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What's the best nursery free of Rose Mosaic virus?

Posted by Strawberryhill 5a IL (My Page) on
Tue, Jan 3, 12 at 12:34

I was checking on Rose Mosaic Virus and found an old thread where aimeekitty posted a picture of her "Queen of Sweden" bought from Roses Unlimited in July. The leaves looked just like Christopher Marlowe that I got from RU in July. I chopped all his infected leaves off, and he was robust in the summer.

We have a mild winter this year, but Christopher Marlowe shriveled up early by frost, while other Austins remained green. Henry_Kusha of Ohio warned that RMV infected roses don't survive the winter well.

I'm used to roses dying in my 5a zone - like the hybrid teas that I planted in full-sun in my last house. But for a zone 5b hardy shrub like Christopher Marlowe to shrivel up is rare. I winter-protected him by mounding soil in a bucket like others, and he's right next to the house.

What's the best nursery free of Rose Mosaic Virus? Many thanks.


Follow-Up Postings:

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RE: What's the best nursery free of Rose Mosaic virus?

Who offers the varieties you're interested in propagated from VI stock? Otherwise, all you can expect is what's been supplied has only been asymptomatic, which, as you've read and seen, means nothing. A nursery can claim anything they wish, and a few have for some time, but unless the stock in question has been tested and certified, it doesn't mean squat. Kim


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RE: What's the best nursery free of Rose Mosaic virus?

Many decent nurseries do their best to offer virus free stock, but the only roses that you can be sure of are those that say they are VI (Virus Indexed). Many fine roses are not available as a VI rose. It is an expensive process.


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RE: What's the best nursery free of Rose Mosaic virus?

To add to the confusion, many varieties have never been seen in commerce virus free. They were infected by being budded onto contaminated rootstock during the evaluation and/or initial propagation phase (before RMV was known to be such a wide-spread problem), and the rose we have seen in commerce has always been infected ... whether it's budded or own-root, since each clone of a given variety is technically a genetic piece of the original plant.

I don't put extraordinary effort into searching out VI plants. If a variety I want does well, I add it to my collection. Nothing in my garden (yet) has shown the classic mosaic symptoms, but this doesn't mean that I can claim that my garden is virus free.

Connie


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RE: What's the best nursery free of Rose Mosaic virus?

Queen Elizabeth, introduced in 1954, was introduced infected. The only way you could possibly find it otherwise is from treated stock. Flutterbye was introduced infected as was Showbiz, a European rose which came out here infected. I bought first year plants from the American introducer of both and both exhibited classic symptoms. Martha's Vineyard, a Poulsen landscape rose which was introduced here about 1996, as an own root rose, is infected. I have a first year, own root plant of it from Arena who only produced it own root and it exhibits mosaic symptoms every year. Even if Arena had budded it, he used VI multiflora and VI Huey from mother blocks which were never budded ON to, only cuttings taken from.

Take a look at Foundation Plant Services list. Hopefully, one of these days, Dr. Manner's list will be updated and obtainable. If the rose you want doesn't appear on either of these two lists, you may well be out of luck.

I agree with Connie. If it performs well for me, I grow it. There are MANY which just have never been available as certified material. Expecting anything to be virus free unless it is advertised as having been produced from VI stock is placing unreasonable demands on the nurseries and is unrealistic. Though it MAY be possible something is new enough to not have been infected by being budded on infected rootstock, there is no guaranty. You know plants can be asymptomatic for decades before exhibiting symptoms. Some may never exhibit them and may grow perfectly well for you with infection. Others may not.

Search out the ones you hope to find, but be realistic. If it hasn't shown up on either of the VI producers' lists, there is no way to know until it's tested and certified or grown and expresses symptoms. If it isn't produced from stated VI material, you pays your money and takes your chances. Kim

Here is a link that might be useful: Foundation Plant Services list of treated roses


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RE: What's the best nursery free of Rose Mosaic virus?

You're right, Connie. No, you can't.

I've had roses that grew here for 20 years, before showing signs of RMV. Our Reine des Violettes was one of those.

BUT also like you, if I want a rose, and it is not available VI, I will grow it virused. I'd rather HAVE the rose, even if virused, than not have the rose at all.

nd maybe because I kept it going, someone, some day, with treat that rose, and make it available without The Plague.

Jeri


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RE: What's the best nursery free of Rose Mosaic virus?

  • Posted by TNY78 6b-E TN (My Page) on
    Tue, Jan 3, 12 at 16:12

I have a Nuits de Young that showed signs of RMV shortly after planting 3 years ago. Since its not contagious, I just let her be, and she's still growing in my garden...she's just a little slower than the others. I kind of think of her as my "special needs" rose. :)
~Tammy


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RE: What's the best nursery free of Rose Mosaic virus?

Strawberry,

I'd suggest you read one of the threads here in September of 2011 in which Dr. Malcolm Manners participated. The link is posted below. Read each one of Dr. Manners' posts. He discusses to which nurseries roses that went through his treatment program were sent. Also, from what he wrote, I don't believe "VI" is terminlogy used for roses that were treated at his college (Florida Southern College). I think VI is associated with roses that have gone through RMV treatment at UC Davis.

In one of Dr. Manners' posts (dated Thu, Sep 29, 11 at 13:14), there is a little snippet of info about the use of "VI" terminolgy. In the last paragraph, he writes:

"In an industry as large and diverse as the American rose nursery industry, undoubtedly someone, somewhere, at some point, accidentally shipped or sold an infected rose and indicated it was "VI" (a term we never use), and so the rumors begin."

I asked Dr. Manners about a list of varieties cleaned in his program and which nurseries might have them, and he responded on Mon, Sep 26, 11 at 3:34:

"Melissa, I'm sorry but I don't have such a list readily available. The three nurseries mentioned above (Vintage, Antique Rose Emporium, Heirloom) have received most of them, over the years, but numerous other nurseries have acquired smaller numbers of varieties."

I've ordered from all three of these nurseries for years, and *of the plants I've chosen to get from them*, none has ever shown any symptoms of Rose Mosaic Virus, although plants from others sources have. Does it mean all roses they have are RMV free? No, but if I have a question about RMV status for a rose I'm considering not indicated by info on the web or in a catalog for a particular nursery, I will ask them.

Just as an example I bought Madame Pierre Oger from Vintage last year. I wanted the rose, and what made me decide to get it there was this statement on the Vintage website, http://www.vintagegardens.com/roses.aspx?cat_id=3 (use the link and scroll down to Mme. Pierre Oger):

"A sport of Reine Victoria and extremely popular. One of the "Shell Roses," with very cupped smallish flowers of ivory usually distinctly edged cerise pink, everblooming. Now a new clean virus-free clone has been made available by our dear friend, Siegfried Hahn."

No mention of "VI" for this rose but others at Vintage do have that designation. However, I trust Gregg Lowery, and if he has the above on his website, that is good enough for me.

On the other hand last year I was trying to buy a plant of Marechal Niel. It is in commerce both virused and clean. The one nursery that had it in stock when I was shopping was not one I'd dealt with before. So I wrote and inquired where they had obtained their MN and whether it was free of Rose Mosaic Virus. The reply was really a non-answer and so unsatisfactory that not only did I not buy Marechal Niel from them, I declined to order anything else either.

Fyi, the plant sale described here looks interesting regarding RMV status (and it's for a very good cause too!):
http://www.flickr.com/photos/mmmavocado/

Melissa

Here is a link that might be useful: GW thread on RMV in RdV bands


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RE: What's the best nursery free of Rose Mosaic virus?

I believe this is a pretty thorough and current list of what we have, indexed free of PNRSV and ApMV, at Florida Southern:

Archduke Charles
Arrillaga
Autumn Damask
Bailey Red
Belfield
Bermuda's Anna Olivier
Bermuda's Kathleen
Bon Silene
Brightside Cream
Carefree Beauty
Carnation
Champney's Pink Cluster
Christian Dior
Clytemnestra
Comtesse du Cayla
Cramoisi Superieur
Crepuscule
Devoniensis
Devoniensis (Cl.)
Don Juan
Duchesse d' Auerstadt
Duchesse de Brabant
Fields of the Wood
Flamingo Gardens Tea
Fortuniana
Gartendirektor Otto Linne
Gate Tayloe Musk
Gruss an Teplitz
Hermosa
Kronprincessin Viktoria
Lady Hillingdon
Leveson Gower
Louis Philippe
Maggie
Maitland White
Maman Cochet
Marechal Niel
Marie van Houtte
Mary Manners
Miss Atwood
Mister Lincoln
Mme. Butterfly
Mme. Lombard
Mons. Tillier
Moonsprite
Morgan Spring
Mrs. B. R. Cant
Mutabilis
Nancy Lee
Nur Mahal
Oklahoma
Old Blush
Papa Gontier
Paul Neyron
Penelope
Pink Pet
Prosperity
Queen Elizabeth
R. laevigata
R. moschata (G. Thomas's)
R. moschata(Elmwd. Cem)
R. palustris
R. roxburghii (double)
R. roxburghii (single)
R. roxburghii (spineless buds)
Red Smith's Parish
Reine des Violettes
Safrano
Saluda Musk
Smith's Parish
Sombreuil
Soncy
Souv. de la Malmaison
Souv. de St. Anne's
Spice
Spray Cecile Brunner
St. David's
Stanwell Perpetual
Temple Musk
Tiffany
Trinity
Vanity
Vincent Godsiff

Of course we're a college, not a commercial nursery. So while we make propagating material available to commercial nurseries, we do not make and sell plant directly to the public, except at special sales from time to time when we have excess plants. But these varieties are always available to nurseries who may want to propagate them.

Because of GardenWeb policy, we can't/won't discuss any sale events here, but you can always contact me by email.

Malcolm

Here is a link that might be useful: Roses at FSC


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RE: What's the best nursery free of Rose Mosaic virus?

Thank you, Kim, Tessie, and Malcolm for extensive info. on virus indexed roses. It's a triple wammy against roses with:

1) wimpy own-root that can't get phosphorus from alkaline soil. My own-root Christopher Marlowe gave tiny flowers around 1". Compared that to Pat Austin, grafted on Dr. Huey, which gave me a 4" bloom coming out of a tiny band.

2) wimpy own-root that can't handle -20 degree in zone 5a. I haven't taken the wind chill factor into account yet. The wind in Chicagoland is brutal. Predfern from my area holds the record of losing the most roses to the winter.

3) Add Rose Mosaic Virus to a wimpy own root in a cold zone and we get a death sentence.

Thank you all for your help.


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RE: What's the best nursery free of Rose Mosaic virus?

I'd like to throw this idea out there:

It's not the rootstock that contributes to the decline, but the health of the plant overall. I think any plant that's small & weak at the end of a season would be a candidate for winterkill regardless of whether it's own root or grafted.

I have many, many own root plants because with winterkill, I'd prefer the plant that emerges the following spring to be the plant I ordered & not the rootstock.

My own-roots are smaller the first year because the plant I order is a small band, as opposed to the grafted roses which are normally a year (or more) older when shipped or sold locally at nurseries.


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RE: What's the best nursery free of Rose Mosaic virus?

  • Posted by seil z6 MI (My Page) on
    Wed, Jan 4, 12 at 12:52

If a rose has grown for 20 years before it showed signs of virus how can you complain? Since some of my roses came from my Mom's collection and are any where from 20 to 50 years old, when no one even thought about RMV let alone indexed it, and they're still doing fine I don't worry too much about it. It's said that in cold climates it reduces a roses winter hardiness. Like I said some of my roses are OLD and it hasn't seemed to effect their hardiness at all. But in warm climates, other than the marked leaves, I don't know what difference it makes.


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RE: What's the best nursery free of Rose Mosaic virus?

I felt that I could NOT complain -- which is why I've never worried about it greatly. BUT I live in a particularly mild climate, so it probably matters less to me than it does to others.

OTOH, IF I have a choice, I will always opt for clean/cleaned/VI stock over virused.

Jeri


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RE: What's the best nursery free of Rose Mosaic virus?

That varies greatly because of many factors, Seil. Some roses are more susceptible to decline due to viral infection than others and improper cultural practices can induce them to decline faster. I've encountered many obviously infected roses here over the past nearly thirty years and there have been widely varying effects. Autumn, the old thirties HT, has demonstrated paisley foliage every time I've seen it, but it's also been a huge plant, loaded with flowers in every garden I've seen it. Weaker types such as Amy Vanderbilt, have been stunted runts which appeared rather "arthritic". My best friend's mother had an ancient plant of Cavalcade which was terribly virused. That thing lingered for many, many years, begrudgingly pushing out a few flowers every year, but Dora refused to dispose of it. The plant had been wonderful when they bought the house in the mid sixties and by the late eighties she kept it out of memory of its former glories.

The individual immune system, combined with the severity of infection and probably how many strains of virus are stacked one upon the other in the plant; added to more severe cultural practices and extremes of climate and situation will probably produce widely varying results. But, I do agree with Jeri, IF given a choice, I'll take an uninfected example over an infected one any day. But, if I can only grow it infected, so be it. Kim


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RE: What's the best nursery free of Rose Mosaic virus?

I'll take it just a bit further. If a virus free rose is available for a variety I want, I'll select that one, even if it costs a bit more.

If only virused roses are available for a particular variety, well, I'll think about how much I really need it.

Rosefolly


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RE: What's the best nursery free of Rose Mosaic virus?

Kim Stated: "I'll take an uninfected example over an infected one any day. But, if I can only grow it infected, so be it."

Please note that Kim lives in a warm?hot? climate where the rose immune system will probably be very effective in severely limiting most types of rose virus (that have mosaic leaf symptons) spread. But Kim how do you know which virus a prospective infected rose has? For example the aphid spread RSDaV virus has been described in the reviewed scientific literature as causing "yellow vein chlorosis in leaves". Also: "RSDaV was detected in 24% of the analyzed samples."

Davis has recently published a paper (in which they used PCR to detect the virus) http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PDIS-92-4-0508 where they announced that they found an APHID SPREAD virus in their indexed rose plantings (see page 511):

"In this test, RSDaV was detected in many different rose species and cultivars from the Foundation Rose Collection at FPS. In all, 129 plants in this collection were tested, and 77 were positive for RSDaV. Some of the hybrid rose cultivars tested positive for RSDaV included Queen Elizabeth, China Doll, Heirloom, Lowell Thomas, Jack Frost, New Dawn, Uncle Joe, Bridal White, Butterscotch, and Cynthia. It is interesting that the virus was detected in more than 69 plants in two rows (total number of plants in these rows was 89) of the collection which were planted in the mid 1990s. In all, 162 samples of R. multiflora from the virusindexing rose blocks also were assayed in the spring and RSDaV was found in 94 plants. The majority of RT-PCR-positive R. multiflora plants were symptomatic. Another 40 additional plants from the same virus-indexing blocks were tested in the summer and 6 were positive."

Here is a link that might be useful: paper quoted above for


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RE: link for aboveWhat's the best nursery free of Rose Mosaic vir

This should be the link that did not work in the above post. Sorry.
http://www.springerlink.com/content/n7006m6l7325156m/

Here is a link that might be useful: Link for above


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RE: What's the best nursery free of Rose Mosaic virus?

  • Posted by seil z6 MI (My Page) on
    Thu, Jan 5, 12 at 3:41

I'm not saying people shouldn't look for virus free roses. I'm just saying that finding one in your garden shouldn't be an automatic death sentence. RMVed roses can and do live for many productive years even in cold climates.

Henry, we are so lucky to have you here to interpret these papers for us. I know I could not wade through all of them and make sense of them like you do. Thank you!


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RE: What's the best nursery free of Rose Mosaic virus?

Seil, it is VERY important that the rest of us "wade through" Henry's papers, since they never say what he claims they say. In this case, the paper in question describes rose rosette disease in Chile, a virus long known to spread by aphids, in a family of viruses always spread by aphids. Note that that virus has only recently been discovered in the US, and is not in any way (I should emphasize not in any way) related to nor similar to rose mosaic, the topic of this thread. Therefore it is utterly (let me emphasize UTTERLY) irrelevant to the current discussion, and is designed to obfuscate the current discussion. No form of rose mosaic (different family of viruses) has ever been shown to spread by aphids. Just as you can catch a cold or the flu from a sneeze, but you cannot catch HIV or Herpes from that sneeze, any such comparison is not valid. Different families of viruses behave in very different ways, and they cannot be compared.

Also, in the statement to Kim about his climate being hot, note that the poster of that statement is the only person on the earth who believes it, and that it is not valid. No spread of mosaic diseases (note that I say the mosaic diseases; not just any old virus, which we are NOT discussing here) has ever been demonstrated to spread, by ANY means, in cold/cool climates; the only spread EVER shown has been at Davis, which is quite a hot climate, and that, by natural root grafts, in very closely-spaced plants. No valid researcher of mosaic has ever suggested the idea; it is made up entirely and uniquely by the poster above, who has no evidence for it, when there is vast evidence (hundreds of millions of roses in millions of gardens throughout the world, over decades of time) without a single demonstrated incidence of spread.

I am truly sorry that the value of this thread has suddenly plummeted, and I may not comment here again, in that once the games begin, such threads always decline into craziness until people just quit posting to them and let them die. That's really unfortunate.

Other comments above are quite valid -- yes, some roses perform acceptably with mosaic virus. Yet I'd agree with those of you who have said that, given the choice, you'd choose a clean plant. And clean plants of many varieties are readily available, with no threat of contagion, and no evidence of contagion, in over 40 years of mosaic research.


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RE: What's the best nursery free of Rose Mosaic virus?2

Ah, I see that the paper linked to is NOT the paper from Davis -- again a bit of sleight of hand. Even at Davis (quoted lines, not linked paper, and no link given), notice that we're talking rose rosette disease, NOT mosaic. they're not the same.


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RE: What's the best nursery free of Rose Mosaic virus?3

Sorry, slip of the typing fingers -- not rose rosette (a disease well-known in the US, important in its own right but also irrelevant to this discussion); the "new" virus is rose spring dwarf -- noted in the Chilean as well as the Davis references.


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RE: What's the best nursery free of Rose Mosaic virus?

Some things are best just ignored, Malcolm. :-)

BTW, I THINK I encountered some roses with rose spring dwarf disease, years and years ago. Early 1990's, IIRC.
It wasn't tested, but it sure had that appearance, and ALL of the bundle of 20 or so plants were so-afflicted.

But, of course, that has nothing atall to do with RMV.

Jeri


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RE: What's the best nursery free of Rose Mosaic virus?

What does Rose spring dwarf-associated virus look like? The linked to link at the bottom gives a picture of Rose spring dwarf-associated virus.

http://www.springerimages.com/Images/Biomedicine/1-10.1007_s11262-010-0510-7-0

The David link below gives pictures of virused roses taken in 1977. Please compare Figure 2 to the Chile picture. The caption for figure 2 is: "Fig. 2. Hybrid tea rose infected with rose yellow mosaic." Also: "The disease can be recognized by light-green to bright-yellow mosaic patterns on the leaves of infected plants (fig. 1 and 2)." Please note this is not a "NEW" virus as it is described in 1977. "The second virus-like disease recently found is rose spring dwarf (RSD). This disease may or may not occur simultaneously with RLC. RSD has been found in commercial nurseries, landscape roses, and public rose gardens.
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http://ucce.ucdavis.edu/files/repositoryfiles/ca3103p4-63242.pdf
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Concerning early known spread of rose viruses (same Davis article): "Rose leaf curl has been found only in public rose gardens, usually in or near plants of "antique" roses. Recent data indicate a slow natural spread, although the vector is unknown. Hybrid tea roses exhibit RLC symptoms, but rootstock varieties do not. Symptoms on hybrid tea roses are downward curling of leaves on established plants and dieback of canes (fig. 4). Leaves easily drop off new shoots, and the shoots are characteristically pointed with a broad base." Also from the same article: "The agent causing this disease is very heat stable, remaining infectious after treatment in vivo for 26 weeks at 38 O C."
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The latest paper (July 2011) concerning roses with mosaic symptoms is from the University of Minnesota.

http://www.actahort.org/books/901/901_18.htm

It is based on Ph.D. Thesis work. Hopefully the thesis will include a good historical section and pictures of infected leaves.
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It should be emphasized that because a rose virus has only been "scientifically characterized" recently does not mean it is a "NEW" virus. One of my main original points is that someone may offer you an infected rose (mosaic symptoms). However, how do you know which virus with mosaic symptoms caused the infection? Do you want to run the risk that that particular virus can spread in your garden (whether by root contact, aphids, nematodes, prunning, branches rubbing against each other, and/or other yet to be reported methods)?

Here is a link that might be useful: link for picture of Rose spring dwarf-associated virus


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RE: What's the best nursery free of Rose Mosaic virus?

  • Posted by seil z6 MI (My Page) on
    Thu, Jan 5, 12 at 12:54

I do not understand what games you are talking about, Malcolm, but I'm sorry if I upset anyone. That was not my intention. I do not always agree with everything posted here but I do respect and want to hear everyone's opinions. How else will I ever learn new things? Maybe I'm completely wrong about something (happens all the time) and hearing someone else's view will click and I'll see things in a different light. So please, everyone, do not stop posting your views just because someone else disagrees with them! This place is SUPPOSED to be about that exchange of ideas.


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RE: What's the best nursery free of Rose Mosaic virus?

I agree with Seil 100% - it's a place for learning, and NOT for who's right and wrong. We don't know all the answers, and it's best to get as many different views as possible. My goal is to understand, rather than to judge. Seil is always nice and fair, and I respect that.

Henry_Kuska has helped me A LOT in reading more and trying new things. Thanks to Henry, I learned about suppression pathogens by soil bacteria and manure, with resulting zero blackpots in my 10 Austins.

Kim helps me a lot too. I was set on ONLY OWN-ROOT and planted 10 own-root Austins this summer, but the nursery sent me a grafted Pat Austin on Dr. Huey. I don't mind, since Pat is reputedly puny. She outperforms ALL my other own-roots in terms of winter hardiness. She gives the biggest bloom - and ranks among my top performers. Kim is right that grafted Dr. Huey is best for alkaline soil. Dr. Huey secrets more acid to neutralize alkalinity. Only Pat Austin has dark green leaves, the own-roots don't look that good, with iron deficiency.

It's interesting that Pat Austin is the only one hardy to zone 6b, while the other nine own-roots are hardy to zone 5b. She's 100% green and still has 5 buds on her. Christopher Marlow, the virused one, is brown and shriveled, an ugly winter sight.

If I have my choice, it's virus free grafted Dr. Huey, for more blooms and bigger blooms. Dr. Huey can extract phosphorus better from alkaline soil. I can plant Dr. Huey deeper, like 4" down, and that gives more protection in the winter (I learned this from Karl Bapst from zone 5a, Indiana).


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Dr. Huey goes own-root eventually in high rain

I learned from Karl Bapst that when planted 4" deep, roses grafted on Dr. Huey become own-root eventually in a high rain climate. Sometimes there are 2 roots simultaneously, and it helps to get extra water and nutrients deep down in the soil with grafted rootstock.

If I'm in a warmer zone, I want own-roots for Austin roses. They get too big and wild with octopus arms, and there's less chance for them to become own root with less rain.


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RE: What's the best nursery free of Rose Mosaic virus?

Malcolm, thanks very much for that list. Now I know of additional rose that have been treated. The list does make me curious though. How do you decide which roses to treat? And are you continuing to treat others? Lastly, have there been any roses that weren't able to take the heat of treatment (for instance died before treatment was finished, thus no cleaned material could be obtained from that plant)?

Thanks!

Melissa


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RE: What's the best nursery free of Rose Mosaic virus?

Seil and Strawberryhill -- sorry, I was not in any way inferring that you were playing games. It is Henry alone who is playing games. Specifically, the diseases and the research he refers to are not rose mosaic, are not related to rose mosaic, and are not relevant to a discussion of rose mosaic, any more than a discussion of HIV, Ebola, or the Marlburg virus are appropriate in a discussion of the common cold. Yes, they're all viruses; no they do not behave in the same manner, they are not spread in the same ways, etc. We're not just comparing apples to oranges here; we're comparing apples to elephants. And this is where all of these discussions eventually lead -- we have good, clear information about rose mosaic, and then it is all bemuddled by Henry comparing it to many other, unrelated viruses, entirely without reason.


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RE: What's the best nursery free of Rose Mosaic virus?2

Tessiess, In most cases the plants were sent to us for treatment. In a few cases, they were simply things that interested me. We've done many more than are on the current list (over 300), but our space limits how many we can keep on campus. So there are roses "out there" at ARE, Vintage, Heirloom, etc., that went through our program.

Yes, many roses don't survive heat therapy, and it's somewhat counterintuitive -- those that "like" hot weather usually end up dying (Chinas, Teas, etc.) since they won't go dormant, whereas cold-weather stuff (Albas, Gallicas, etc.) are easy -- they just hunker down in survival mode and stick it out beautifully. So in many cases we had to try several times before getting one through alive. But once a surviving bud has made it through the heat, we always test by three methods ('Shirofugen' cherry, ELISA, and 'Mme. Butterfly' bioindexing) and to date, have never had a plant remain infected with mosaic.

And I'm not trying to cause problems here -- I just think it important to point out that we really do know quite a lot of things about mosaic. It's not mysterious or unknown as Henry seems to believe it to be. If other institutions that deal with the disease disagreed with me, then yes, there would be good reason to wonder. But note that they don't. Everyone who actually works with mosaic at FSC, UC Davis, Oregon State U., University of Washington, elsewhere in the world are in complete agreement about every aspect of the disease. So it really annoys me when someone very knowingly confuses the issue by talking about other, unrelated diseases, and then hinting that they behave the same way, or they make up "facts" about the behavior of the viruses that cause mosaic, based on temperatures in the climate where they occur, when he knows that no one, ever, anywhere, has even suggested those "facts;" rather, that he has simply made them up to be argumentative. That is not acceptable or reasonable in a discussion such as this.


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RE: What's the best nursery free of Rose Mosaic virus?

Malcolm, is there some designation your program puts on the roses you've treated, like the "VI" designation Davis uses? I understand it's completely up to the individual nursery to advertise whether or not their stock has been tested/treated and I realize the space/labor/funding resource issues your institution operates under, as well as not attempting to maintain varieties you've tested which weren't suitable for your climate, but you have to admit it is disheartening knowing you've produced stock from three hundred plus varieties, many of which have been OGRs, and it is virtually impossible for those who wish to grow them, to FIND them. When you browse the wonderful list of previously treated roses and realize these are only a small portion of what's been produced, it hurts there is no way to FIND them in commerce.

You've had many really interesting things run through your program and I know MANY would LOVE to be able to buy them, me for one! I can imagine some don't wish to advertise theirs is treated for fear someone might take issues and over react as has too often been done concerning unstable rose sports, and I can understand not wanting to wade into the virus quagmire unnecessarily. But, surely there is SOME method of finding sources for the material you've produced we can buy other than each person contact each nursery and inquire what the source of their material was? Kim

Here is a link that might be useful: ARS reprint of treated roses and article


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RE: What's the best nursery free of Rose Mosaic virus?

Kim, I know Vintage and ARE will tell you if a plant came from us, and as far as I can recall, except perhaps for some recently "found" roses, anything we've sent them would certainly have been indexed clean. Same with Heirloom, although they no longer carry as large a selection of OGRs as they used to. We have also sent roses to Roses Unlimited and other nurseries in the past, and I really don't know which ones -- it's unfortunate that we did not keep exact such records. So unfortunately, no, I don't know of a better way of finding out, than to ask a specific nursery about a specific variety.


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RE: What's the best nursery free of Rose Mosaic virus?

Dang. Thank you. I guess that's the answer to the thread question. Thanks. Kim


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RE: What's the best nursery free of Rose Mosaic virus?

  • Posted by seil z6 MI (My Page) on
    Thu, Jan 5, 12 at 20:10

Thank you for your explanation, Malcolm. I do look at the papers Henry posts and I was totally aware that the paper concerned was about a virus other than RMV. I just appreciate it when Henry gives a synopsis of the paper in English because scientific jargon is about as understandable as legalese to me.

The list you posted has some wonderful old roses on it But I was wondering if you have done anything with the "older", like 40s to 70s, modern HTs that were pretty much bred virused?


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RE: What's the best nursery free of Rose Mosaic virus?

Well, not "bred" virused, but definitely introduced infected. Ralph Moore had a stand of enormous Queen Elizabeth and radiation induced White Queen Elizabeth Dr. Walter Lammerts gave him prior to the variety's introduction. Both were severely virused. The mosaic patterns (or what appeared to be RMV) were obvious year in and year out for all the many years I observed them. That was why he refused to propagate either of them for sale. I thought the radiation induced white sport quite interesting. If pre production plants were infected, what chance did anyone really stand of obtaining it uninfected commercially?

From two lists referred to here, he's at least worked on these. The ones starting with Capt. Christy are from the 1993 ARS reprint list. How neat it would be to determine where these materials are now! Kim

Christian Dior
Don Juan
Mister Lincoln
Moonsprite
Oklahoma
Queen Elizabeth
Tiffany
Captain Christy 1873 HT
Crimson Glory 1935 HT
Dainty Bess 1925 HT
La France,Climbing 1893 Cl HT
Mme. Butterfly 1918 HT
Nancy Lee1879 HT


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RE: What's the best nursery free of Rose Mosaic virus?

One that is glaringly absent from my list above and should be there is 'Peace'! We do have it, mosaic-free. I recall discussions here many years ago about cultivar degradation, and what caused it, and it was suggested that among other possible explanations might be acquisition of mosaic or, perhaps, other viruses, and that it would be interesting to see if heat-treated plants were rejuvenated. And a prime example, I think, of where that may have happened is in 'Peace', which is vigorous and colorful, as the old descriptions and photos of indicated that it used to be.


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "I do look at the papers Henry posts and I was totally aware that the paper concerned was about a virus other than RMV."
-------------------------------------
H.Kuska comment. As used in garden circles, RMV is not a virus. It is a group name for rose viruses that exhibit mosaic symptoms.

One my web page I state: "As background material the term "rose mosaic virus" means different things to different people. Here are 2 scientific literature examples of the complexity of this subject (which illustrate why I decided to use the term "Rose Viruses" in the title instead of "Rose Mosaic Virus").

1)

Title: Roses: virus and virus-like diseases.
Author: V. Lisa
Published in: Colture-Protette. 1998, 27: 5 Supplement, pages 35-38.
Abstract: "Notes are given on the viruses and virus-like diseases that are known to affect roses around the world. The most common and widespread virus disease is rose mosaic, associated especially with prunus necrotic ringspot ilarvirus (PNRSV), apple mosaic ilarvirus (ApMV), arabis mosaic nepovirus (ArMV) and strawberry latent ringspot nepovirus (SLRV), but also with tobacco ringspot nepovirus, tobacco streak ilarvius and tomato ringspot nepovirus. Tobacco mosaic tobamovirus and an unidentified closterovirus are found sporadically. The virus-like diseases of unknown aetiology include rose ring pattern, rose flower break, rose streak, rose rosette (or rose witches' broom), rose leaf curl, rose spring dwarf and rose wilt. Other disorders are caused by hormonal imbalances or other types of incompatibility between the graft and the rootstock of unknown aetiology, such as rose bud proliferation, rose dieback (or rose stunt) and frisure. Techniques for diagnosing viruses in roses and methods for their control are described."

(The actual articles are copyrighted. This is why one will only see the abstract on public forums.)

AND 2)

Title: Characteristics of rose mosaic diseases

Author: Marek S. Szyndel

Published in: Acta Agrobotanica 57(1-2): 79-87, (2004)

Summary: "Presented review of rose diseases, associated with the mosaic symptoms, includes common and yellow rose mosaic, rose ring pattern, rose X disease, rose line pattern, yellow vein mosaic and rose mottle mosaic disease. Based on symptomatology and graft transmissibility of causing agent many of those rose disorders are called "virus-like diseases" since the pathogen has never been identified. However, several viruses were detected and identified in roses expressing mosaic symptoms. Current1y the most prevalent rose viruses are Prunus necrotic ringspot virus - PNRSV, Apple mosaic virus - ApMV (syn. Rose mosaic virus) and Arabis mosaic virus - ArMY. Symptoms and damages caused by these viruses are described. Tomato ringspot virus, Tobacco ringspot virus and Rose mottle mosaic virus are also mentioned as rose pathogens. Methods of control of rose mosaic diseases are discussed."

Link for Szyndel's abstract:
http://agris.fao.org/agris-search/search/display.do?f=2009/PL/PL0907.xml;PL2009000639

Please note: "Currently the most prevalent rose viruses are Prunus necrotic ringspot virus - PNRSV, Apple mosaic virus - ApMV (syn. Rose mosaic virus) and Arabis mosaic virus - ArMY." He does not say ONLY, he states "Currently THE Most Prevalent".

( Marek S. Szyndel, is the author of the chapter "Viruses" (180-189) in the Encyclopedia of Rose Science (2003).)

---------------------------------------------------------------------- ------------------------------------------------------------------
Heirloom roses has a link about rose mosaic virus. They do not identify the scientific names of the individual viruses that together are called RMV, but instead (wisely, I think) identify RMV by symptoms. Please look at symptom 4, vein banding, and the corresponding picture.

http://www.heirloomroses.com/care/rose-virus/

Here is a link that might be useful: link to my web page


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RE: What's the best nursery free of Rose Mosaic virus?

Another yellow vein virus in roses of interest to members of the Antique Rose Forum:
"Genome characterization and transmission of Rose yellow vein virus, a new caulimovirus occurring in garden rose
D. MOLLOV (1), B. Lockhart (1), D. Zlesak (2)
(1) University of Minnesota, St. Paul, MN; (2) University of Minnesota, Andover, MN
Phytopathology 99:S87
A previously undescribed caulimovirus was identified as the causal agent of a vein yellowing disease of rose. The virus has spherical particles 48�50 nm diameter containing a circular dsDNA genome approximately 8.6 kb in size.
The virus was named rose yellow vein virus (RYVV) and occurred in an unnamed Damask rose in Minnesota and in the varieties �Belle Poitevine�, �Madame Pierre Oget�, �Mozart�, �Prosperity�, and �Schnezzwerg� in New York. The virus was not transmitted by mechanical inoculation or by Macrosiphum euphorbiae, but was graft transmitted to healthy plants of the variety �George Vancouver� in which characteristic vein yellowing symptoms developed and the presence of RYVV verified by PCR using virus specific primers. The genome organization of RYVV was similar to that of known caulimoviruses but the degree of sequence identity between homologous genomic regions was low (22�51%).

Here is a link that might be useful: Use your search command to find the paper.


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RE: What's the best nursery free of Rose Mosaic virus?

"As used by gardeners," rose mosaic in the USA is well more than 99% PNRSV, substantially less than 1% ApMV, and so exceedingly much less than 1% all other viruses combined as to be completely ignorable and irrelevant. Arabis Mosaic is not currently believed to be present in US-grown roses. If other viruses developed significant populations among American growers, we'd rightly become more concerned. But they have not. So if a grower has "mosaic" in his/her garden, One can be WAY more than 99.99% sure they're talking about PNRSV/ApMV specifically and uniquely, and therefore, as I've stated too many times, other discussions are merely confusing and meant to destroy the discussion. Again my comparison, if someone develops a runny nose and feels like they're coming down with something, and say they think they have a cold, we do not immediately quarantine them for ebola or smallpox or something else deadly, and start proclaiming that their death is imminent, start the air raid sirens and run screaming from the cities! Fear mongering is not merited here. Yes other viruses are interesting, and these publications get written because they are interesting new discoveries that are not the norm. But they are not (and should not be) a consideration in this discussion. The rather simple facts remain -- In all questions on this forum that I've ever seen that have started out about "mosaic virus," the discussion then continues for a bit, with reasonable and knowledgeable discussion of the common mosaic disease. Then suddenly, the entire conversation is hijacked by someone who suggests a plethora of other diseases, all of which are vanishingly rare and are NOT what the questioner asked about at all, but nevertheless, the conversation is taken over to the point it will never again be useful. Suggestions are made that their disease is spreading by all kinds of means known or unknown for other viruses, etc. It is also suggested that local weather has caused some of us to misunderstand the disease (never pointing out that that concept was made up by the poster in question -- it is not even considered by anyone else, and it is demonstrably utterly false). The whole thread is worthless at that point. Here, it has happened yet again. Sorry. I'm done talking now. Another mosaic discussion down the drain. Those who actually know something about the disease will continue to grow healthy roses and provide them to the nursery industry who will continue to grow and sell healthy roses, and we can only hope that the irrational panic will be appropriately ignored.


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RE: What's the best nursery free of Rose Mosaic virus?

hoorah - a good scientific spat for the new year, yay! I returned to gardenweb after an absence, when a full-on row was developing between the two eminent rosarians - you know who they are) which went on for pages and pages - fantastic. A bit more flaming, a few choice epithets would have been perfect - all add colour to a humdrum day. I could almost touch the exasperation emanating from Florida. And hey, these fairly gentlemanly disagreements have nothing, NOTHING on how historians behave. Surprised the courts are not stuffed with defanation cases. True, Mr.Kuska is the king of obfuscation but there is considerable pleasure to be found following Mr.Manners descent from gentle chiding to full-on outrage. A happy plea from the queen of contention - keep it up, guys, this is the web equivalent of bare-knuckle fighting.


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RE: What's the best nursery free of Rose Mosaic virus?

A scientific discussion includes references for one's statements. The link that I gave for Davis (which one reader is unable to find) on Thu, Jan 5, 12 at 0:01 gave the percent of rose spring dwarf found in their treated beds. There was a post somewhere where someone wanted to order a virus index rose from Davis only to be told that it contained rose spring dwarf. Unfortunately, I cannot find it. Has anyone communicated with Davis lately about the rose spring dwarf problem in their virus indexed roses?

My original post in this thread was directed to Kim. Does Kim have to be concerned about receiving an aphid spread rose spring dwarf infected rose if he accepts a rose with yellow vein symptoms? Please see the link below.

http://www.prevalentviruses.org/subject.cfm?id=58465

Do the California readers feel that the above is consistent with the statement: "and so exceedingly much less than 1% all other viruses combined as to be completely ignorable and irrelevant." I try to present scientific information with documentation. I am saddened that someone feels that "True, Mr.Kuska is the king of obfuscation"
------------------------------
I suggest that the readers read the following thread to get an example of what a rose virus discussion can be like:

http://www.rosebreeders.org/forum/read.php?2,37093,page=1
AND
http://www.rosebreeders.org/forum/read.php?2,37093,page=2

Here is a link that might be useful: One view of the situation in California


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated (Without documentation): "It is also suggested that local weather has caused some of us to misunderstand the disease (never pointing out that that concept was made up by the poster in question -- it is not even considered by anyone else, and it is demonstrably utterly false)."

H.Kuska comment: My information (with documentation) is presented at the following link:

http://home.roadrunner.com/~kuska/high_temperature_effect_on_pnrsv.htm

I will pull out some key statements in an attempt to get the reader to read the whole document.

"The heat of summer inhibits virus activity." (Univ of Illinois)
AND
"Cool temperatures tend to favor virus multiplication and disease development within the rose plant." (Univ of Arkansas)
AND
"Same test on September 1, 1999 - all samples were ELISA negative - they could not detect the virus!" (Reviewed published scientific paper from France)

Here is a link that might be useful: discussion of high temperature effects


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RE: What's the best nursery free of Rose Mosaic virus?

Obfuscation indeed. Notice that I did not claim that temperature has no effect of virus titre -- I've known and acknowledged that for the last 30 years. Rather, what I said was that he has made up the concept that those of us who live in warmer climates don't understand how the disease works. In fact, we understand, quite clearly, exactly how the disease works. All of the documentation on Henry's site appears to be true and valid, and yet none of it supports his arguments here in any way. Some of it refers to other, unrelated viruses, and is therefore irrelevant to this discussion, whereas the temperature information is all stuff we already knew and agreed with entirely. But notice what is entirely missing from all that documentation: Henry claims that mosaic is contagious in cool climates, and the reason we in hot climates don't know that is that we live in hot climates. None of the documentation provided on that site (or that exists in the published literature anywhere) supports, nor even suggests, that concept.

The other concept that he has touted in the past, related to this concept, is that those of us in hot climates are incapable of reliably testing for the presence of mosaic. Again, silly nonsense. We're actually very good at that. In more than 30 years of work with the disease, we've never claimed a single plant was clean, only to have a cool-weather grower (or any grower anywhere) later discover that it was not clean after all. I suspect the same is true for Davis and other facilities -- the system of indexing isn't merely good; it's utterly, perfectly good. Yes, there are times when an individual test is inconclusive. And guess what! We don't then conclude anything! We test again later. All tests always include known positives and known negatives, and are tested "blind" by the lab that does the testing. For a conclusive "VI" certification, the plant will test clean by all three methods used, while in the same tests, all control negatives will have been declared negative and all control positives will have been declared positive. It's slow and expensive, but it works. And again I would note that there appears only to be one person on this earth who doesn't think the system works, and he thinks that without shred of evidence. Interesting.


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RE: What's the best nursery free of Rose Mosaic virus?

Concerning the above first paragraph. "Henry claims that mosaic is contagious in cool climates,..."
H. Kuska comment: Is that stated in my temperature link? NO.
Is it stated by me in this link? NO.
Is it stated in the earlier link to another thread in this thread? NO.
In what thread is that stated?
Unfortunately most of the virus discussions have scrooled off the board. My memory is that I consistently have stated that the evidence does SUGGEST that and that cool climate experiments are needed to test it.

Regarding cool climate published scientific literature for a yellow rose veining virus.

"Tobacco streak ilarvirus was found by R. H. Converse and A. B. Bartlett naturally infecting roses in the U.S. (in 4 locations). They published a paper in Plant Disease Reporter, volumn 63, pages 441-444, (1979). They studied 21 wild rose plants from 17 Oregon, U.S.A. locations. 5 plants out of the 20 that were tested by agar-gel diffusion (1 plant was not tested) were found to have tobacco streak virus (often the "ilar" is dropped). The positive testing plants came from 4 of the 17 sites (2 positive out of 2 tested from one site; 1 out of 1 tested from another site; 1 out of 3 from another; and 1 out of 1 from another)."

(Tobacco Streak virus is another leaf vein yellowing virus).

The general transmission information (not specific to roses) is:
"Transmitted by a vector; an insect; Frankliniella occidentalis and Thrips tabaci; Thysanoptera (possibly by allowing virus from the surface of infected pollen to enter through feeding wounds; Sdoodee and Teakle, 1987). Virus transmitted by mechanical inoculation; transmitted by grafting; not transmitted by contact between plants; transmitted by seed (in Chenopodium quinoa, Phaseolus vulgaris, Datura stramonium to different extents); transmitted by pollen to the pollinated plant."

http://www.agdia.com/testing-services/Rose.cfm
http://www.acdiainc.com/rose.htm
http://www.agls.uidaho.edu/ebi/vdie/descr811.htm
---------------------------------

In my web page concerning possible spread by pollen, I state:

"I conclude that the studies indicate that natural field infected pollen transmission in cooler climates will probably be low. But, for a cool climate hybridizer who shields the mother from foreign pollen the existing research cannot be used to exclude the possibility that some infected seedlings will be produced if one uses infected pollen.

----------------------------------------------------------------------

I would like to suggest what I consider to be a definitive experiment regarding PNRSV transfer from infected pollen through rose seed to seedlings: hand pollinate a statistically significant number of fertile non-infected roses (that had their own pollen removed) with diseased pollen from an infected rose (or several infected varieties) that is (are) known to cross with them. The hand pollinated flowers would then be covered to prevent stray pollen from contaminating the chosen flowers (the seedlings raised from the seeds resulting from these crosses would have to be kept in an insect free environment, and sanitary procedures utilized to prevent "after germination" contamination in order for the experiment to be considered truly definitive). The experiment would have to be carried out in a cool climate or in a temperature controlled greenhouse. The seedlings would then have to be tested by one of the sensitive methods as visible symptoms alone is not sufficient."

END OF QUOTE from my web page.

Present H.Kuska comment: Please note the suggestion that the studies be done in a cool climate.
----------------------------------

The second part of the above posters statement contains: "And again I would note that there appears only to be one person on this earth who doesn't think the system works, and he thinks that without shred of evidence. Interesting."

H.Kuska comment. The above can be compared with my web page on the subject:

http://home.roadrunner.com/~kuska/discussion_of_whether_virus_have.htm

Here is a link that might be useful: my web page


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RE: What's the best nursery free of Rose Mosaic virus?

I'm done. I knew from the beginning it was hopeless, but I hope a few silent readers have learned some things along the way. That's the only reason I keep such arguments going for a while. I stand by all my statements above, and all mosaic researchers would agree with me.


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RE: What's the best nursery free of Rose Mosaic virus?

It's above the call of duty, Malcolm, but most here really DO appreciate your willingness to share knowledge -- PARTICULARLY when it is made difficult in this way.

So, though I have said it before, THANK YOU.

Jeri in SoCal


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RE: What's the best nursery free of Rose Mosaic virus?

I find it very disappointing that someone feels that statements about others can be made and not documented.

I had forgotten that Google keeps records of garden.web sites even when the garden.web search no longer reports them.
If you enter:
site:forums2.gardenweb.com kuska roses rmv mosaic
into the Google search engine, you can find 57 of my earlier postings on the subject of rose viruses. Of particular interest is what I have said about virus spread in northern rose gardens:
---------------------------------
"In addition there "may be" above ground spread in northern climates. Previous research was carried out in hot summer climates; recent science reports that the plants' immune system defences are efficient at high temperatures but do not function well at lower temperatures (against PNRSV). See the following link for details:

http://home.roadrunner.com/~kuska/info_about_virus.htm
------------------------------------------
One of the most common viruses under the collective name of "Rose Mosaic Virus" (RMV) is PNRSV. This virus is a temperature sensitive virus. In southern climates the risk of transmission is probably small as the virus will probably be mainly in the roots for much of the season. In Northern Virgina I would have some concern about spread.
-------------------------------------------------
Based on this investigation I feel that shoot contact (branches of nearby roses rubbing against each other) should be investigated. Of course, because I feel that PNRSV is a temperature sensitive virus, I feel that a northern University would provide the most unambigious results.
-----------------------------------------------
In my link above, I state:
"Summary

Contrary to early "thinking" plants do have an immune system (natural defenses). As the temperature increases: the plant's natural defenses are better able to overcome the virus so the concentration of virus is decreased (or possibly even eliminated in the above ground parts of the rose. So any type of above ground spread such as: use of pruners, branches touching, pollen spread by insects, seed transfer) would be decreased. Thus, until spread research is done in northern climates, I recommend that basic precautions be utilized to prevent/minimize the possibility of above ground spread."

Here is a link that might be useful: link referred to


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RE: What's the best nursery free of Rose Mosaic virus?

July 22, 2011 rose virus information from the University of Florida.

Please look at page 31. It appears that they think that RMV is a name of a particular virus.

Please look at page 34 regarding spread (I wonder if they are referring to root contact???).

Here is a link that might be useful: Univ of Florida slide (?) show


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RE: What's the best nursery free of Rose Mosaic virus?

Rose Spring Dwarf has been reported in Turkey. See:

http://cat.inist.fr/?aModele=afficheN&cpsidt=21817476
http://www.springerlink.com/content/t3j217248h36n325/

Here is a link that might be useful: second link above


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RE: What's the best nursery free of Rose Mosaic virus?

I haven't read through all the comments here. I just want to say, I even noticed some strange water mark pattern on my garden weeds.

My assumption is, sucking insects could probably pass the virus to any plant. I'm starting to get used to seeing this virus on my roses. I'm not bothered by this virus as long as my roses are performing. Plus, it gives me the reason to try out new roses.

I don't thing nursery people will sanitize every secateurs they used when they prune roses.


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RE: What's the best nursery free of Rose Mosaic virus?

jumbojimmy, yes it is possible that rose spring dwarf could be spread by aphids from weeds to roses. I am saying this becaus a virus very similar to rose spring dwarf has been been reported to spread from clover to soybeans by aphids (but at a low rate).
-------------------------------
I would like to comment about the use of non rose based studies. Very little rose virus research is done relative to the amount of research on food crops. A good "rule" in science is that nature is consistent. If a certain virus is spread by aphids in, say, apple, and the same virus has not been observed to spread by aphids in roses; one must look for the reason(s) for the observed differences. One possibility is that the rose spread study was done in an area that did not have the correct type of aphid while it was present in the apple area. Another possibility is that the apple study was done in a cool climate where lots of virus was in the apple sap and the apple immune system was not very effective due to the lower temperature in the cooler climate where apples are grown while the rose spread study was done in a hot climate where during the peak aphid population time the virus was mainly in the roots and the enhanced high temperature immune system was able to "control" the small amout,if any, of the virus that was passed to the roses by the aphids.

Of course. actual controlled experiments have to be designed to test the possibilities.

Here is a link that might be useful: clover to soybean report


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RE: What's the best nursery free of Rose Mosaic virus?

The Davis Extension Service rose virus article has moved to a new link with a 2012 copyright. I do not have a copy of the old version to see what changes, if any, were made.

http://ceventura.ucdavis.edu/Gardening/Coastal/Landscape_578/Viruses_Menu/Rose_Virus/
-----------------------------------
The following University of Georgia 2009 (updated on Tuesday, January 10, 2012) article may be of interest, especially to southern rose growers:

http://www.caes.uga.edu/publications/pubDetail.cfm?pk_id=5977
"Viral Diseases
There are several viral diseases of roses. Most of these maladies are transmitted to non-infected plants through vegetative propagation processes used by commercial rose producers or through pruning. There is some evidence that at least two of these viral diseases are transmitted to other plants by insects or spider mites. Viral infected roses tend to be less vigorous, are more susceptible to other diseases, and are less likely to tolerate environmental stresses as healthy plants do.

There are at least six known viral diseases of roses. Yellow and green mosaic patterns, leaf distortion and ring spots are possible symptoms of virus infections. (Figure 12) Others that exhibit viral-like symptoms have not been linked to a particular virus. It is not unusual to encounter plants infected with more than one virus. Also, such occurrences usually cause problems in positive identification.

Some chemical toxicities and nutrient deficiencies express symptoms similar to those caused by viral diseases. Removing severely infected plants may be the only solution. Preventive measures to prohibit the spread of viruses include disinfecting pruning shears when moving from one plant to another, and a good insect control program is a must. Also, buy plants that are apparently healthy and exhibit no peculiar foliar symptoms (Figure 13)."
---------------------------
Please notice that neither article has utilized the term "RMV" ).
-----------------------------
Here is another newly characterized rose virus that is in the U.S.: "The novel virus, named hereafter Rose virus 1 (RsV-1) shared about 70% nucleotide identities with Strawberry necrotic shock virus (SNSV) and Tobacco streak virus (TSV) and less than 50% identities with the other two rose-infecting ilarviruses, Prunus necrotic ringspot virus and Apple mosaic virus." This virus was renamed: "Blackberry chlorotic ringspot virus (BCRV)" due to its near identical " 85-90% nucleotide identity (85-93% amino acid identity) ".
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3059.2006.01410.x/full

Here is a link that might be useful: Davis extension service article


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RE: What's the best nursery free of Rose Mosaic virus?

Thank you, Malcolm. You've given me interesting and reliable information for a long time, and I appreciate your being on this forum. Lou


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RE: What's the best nursery free of Rose Mosaic virus?

Although this article does not specifically mention roses, it sounds familar to what has been reported for roses:
"These procedures work well to produce virus free materials most of the time, but my research has shown that virus levels may be temporarily reduced below the level of detection resulting in a negative virus test, but after some time (several weeks), as the plant matures, virus levels return to normal allowing a positive test result. This time frame means that initial screening will declare a plant as virus free, it is sold to growers and just about the time plants are ready for propagation they test positive and responsible growers eliminate them from the production cycle. This can cause huge losses in time and money especially if large scale propagation of cuttings has already occurred. Another pitfall is the presence of new, unknown viruses for which there are no available detection methods. If there are no symptoms and no appropriate tests, virus infections can be missed."
A QUOTE FROM:
Title: Optimizing detection and management of virus diseases of plants
Author: Deborah M. Mathews, Ph.D.
Author's affiliation: Assistant Cooperative Extension Specialist/Plant Pathologist
Department of Plant Pathology and Microbiology
University of California, Riverside
Riverside, CA 92521

Here is a link that might be useful: Plant Pathologist article


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RE: What's the best nursery free of Rose Mosaic virus?

If one is interested in why/how plant virus infections result in mosaic symptoms, the following paper appears to give the answer.

Here is a link that might be useful: 2011 major breakthrough


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Thank you, Henry_Kuska for the articles you posted

Hi Henry: I read all the links you posted, and appreciate the info. very much. The articles you posted are from creditable sources, Ph.D's. in plant microbiology. While furthering the understanding of plant virus, you got judged. Henry, I feel bad that you are misunderstood. Your intention is to enrich our understanding about other plant viruses, and NOT to undermine Malcolm's work. I started the thread to gather info., and thank you all, Malcolm, you Henry, Kim, and others for your input.

From the Genetics and Microbiology classes I took in college, the heat-treatment work that Malcolm did is 100% valid, it's the moist environment of the nursery that is more conductive to virus-transmission. Virus lives on moist medium, or live tissue. In humans, new strains of flu develop in Asia, starting in birds or pigs, and then moving to human. Information about influenza: "Flu passes from one person to another through droplets in the air. When a person coughs or sneezes, millions of viral particles are sprayed in the air. When the virus is inhaled, it multiplies."

The nursery's green house environment of misting and spraying facilitates the transfer of plant virus. That's DIFFERENT from our garden environment of full sun and dry air. Again, virus needs a moist medium or live tissue to survive. I don't sterilize my garden shears, I just wipe it dry with a paper towel, or let the sun zap all bacteria and fungi. However, I don't underestimate the mites and aphids' ability to transmit virus - since virus needs a live tissue to survive.


A wise man once said, "First seek to understand, rather than to judge." I asked my friend who was completing both her M.D. and Ph.D. in biochemistry what she accomplished, she said, "we spent all our research just to understand how things work, we are not proving anything." That's also my goal.


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "However, I don't underestimate the mites and aphids' ability to transmit virus - since virus needs a live tissue to survive."

Since the main "known" virus to spread by aphids to roses is "rose spring dwarf" (a member of the Genus Luteovirus, Family Luteoviridae), I will only present information concerning this family.
"Aphid transmission of luteoviruses is persistent, circulative and nonpropagative. The viruses are acquired during long-duration feeding, when aphid stylets probe into infected phloem. Virions circulate in the aphid body before being injected into new phloem cells together with saliva during feeding (Figure 3). The viruses do not replicate in vector tissues. Once the aphid has acquired the virus, it can be transmitted throughout the life of the aphid, even after molting (FE Gildow, in Smith and Barker, 1999; Brault et al., 2007)."

Here is a link that might be useful: link for aphid - luteovirus behavior


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RE: What's the best nursery free of Rose Mosaic virus?

I am sorry, once again the link stops working. Try putting the authors' names ( Veronique Brault, Etienne Herrbach, Caren Rodriguez-Medina ) into Google Scholar. When I do that, I get the full paper. Please let us know if that works.


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RE: What's the best nursery free of Rose Mosaic virus?

Thanks Henry, for that very interesting paper. It always amaze me how virus hijacks the DNA system. That paper does a good job in explaining aphids as a vector. I haven't figure out how new strains of flu develop in birds and pigs, then jump on to humans in Asia.


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RE: What's the best nursery free of Rose Mosaic virus?

The virus group at U. Cal. Davis has just published a reviewed scientific paper that (I feel) relates to the general question of sensitivity of plant virus detection methods.

Title: "Comparative procedures for sample processing and quantitative PCR detection of grapevine viruses"

Authors: Fatima Osman (a), Tammi Olineka (b), Emir Hodzic (b), Deborah Golino (a), Adib Rowhani (a)

Authors affiliation: a) Department of Plant Pathology, University of California, Davis, CA 95616, USA
b) Real-time PCR Research & Diagnostic Core Facility (TaqMan� Services), School of Veterinary Medicine, University of California, Davis, CA 95616, USA

Published in: Journal of Virological Methods,Vol 179, pages 303-310, (2012)

"1. Introduction
Diagnostic methods for the detection of grapevine viruses have evolved throughout the years. These methods include, biological indexing using woody indicators and herbaceous hosts (Habili et al., 1992), enzyme-linked immunosorbent assay (ELISA) (Engel et al., 2008; Nolasco, 2003; Frosline et al., 1996; Walter and Etienne, 1987; Demeke and Adams, 1992; Hu et al., 1990; Rowhani, 1992; Rowhani et al., 1997), PCR (Wetzel et al., 2002; Fattouch et al., 2001; Rowhani et al., 1993; Minafra et al., 1992), multiplex PCR (Gambino and Gribaudo, 2006; Faggioli and La Starza, 2006; Dovas and Katis, 2003), quantitative PCR (qPCR) using TaqMan� probes (Pacifico et al., 2011; Bertolini et al., 2010; �Cepin et al., 2010; Osman et al., 2007; Osman et al., 2008; Osman and Rowhani, 2008), low density array (LDA; Osman et al., 2008) and microarrays (Engel et al., 2010; Abdullahi and Rott, 2009). Limitations of biological indexing include the requirement of indexing space and the prolonged period of symptom development, whereas ELISA�s disadvantages include its inability to detect low titer viruses (Rowhani et al., 1997) and the absence of multiple antibody preparations capable of detecting all of the known types of grapevine leafroll associated viruses (GLRaVs; Frosline et al., 1996). Due to the complexity and constraints posed by these two methods, rapid high throughput and reliable PCR-based methods are used more commonly for the rapid detection of viruses in grapevine. These methods are more sensitive, specific, and fast and can be 100�1000 times more sensitive than ELISA (Rowhani et al., 2000). qPCR�s practical simplicity together with its combination of speed, sensitivity, and specificity have made it a method of choice for grapevine virus diagnostics (Pacifico et al., 2011; Bertolini et al., 2010; �Cepin et al., 2010; Klaassen et al., 2011; Osman et al., 2008; Osman and Rowhani, 2006, 2008; Beuve et al., 2007; Osman et al., 2007). In addition, RT-qPCR assays have broad range of detection and could detect virus isolates previously undetectable by conventional RT-PCR."
-----END OF INTRODUCTION QUOTE --------------
SEPARATE ARTICLE. The following link:
http://ucanr.org/sites/natcpn/files/86252.pdf
gives an "insider" meeting discussion that one may find interesting.

"She warned that, even with upgraded and more precise MST techniques, RSP was always detected when testing techniques were upgraded."

"As testing has become more sophisticated, the new technology has increasingly revealed more viruses. Maher Al Rwahnih indicated that if everyone would use the QPCR technology to test their respective vineyards, all of them would result in some positive results for RSP and other minor viruses, regardless of the results of prior testing. Rhonda Smith agreed that consistently raising the bar by using more sensitive technology in testing will always result in discovery of new pathogens and stacked viruses."

Please read the full report to put the above quotes in proper context.

Here is a link that might be useful: link for Davis scientific article


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RE: What's the best nursery free of Rose Mosaic virus?

Malcom... Thank you for the excellent explanations. I am looking around right now to find virus free stock to start my own collection (I think the fortuniana I have is diseased) and the information you have provided is very useful in determining where to replace it... which I sadly probably will.

i have a question then...
What causes the degradation of the variety then over time?
If the rose returns to its original state, is it the plant getting weaker, or the virus getting stronger? i'm guessing the virus has a slow mutation rate and could


Henry, you don't seem to understand anything you talk about...though there is no way to convince you of this.

lol.

Strawberryhill. I appreciate you wanting to jump in and defend your friend, but your comparison of a plant virus to a human one was so humorous I have yet to stop laughing.

Both of you would do well to listen to those that understand this and stop relaying bad information. Unfortunately some people will believe the two of you.

I say this as someone who has at least some minor experience working in scientific labs. Your conjecture contains so many inconsistencies that it betrays a complete lack of understanding in regards to the material and biochemistry involved.

Cheers.


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RE: What's the best nursery free of Rose Mosaic virus?

Sorry... I didn't finish my question...

*could not quickly adapt to a particular variety... even over a 50 year time span.

I'm curious about what causes the actual decline. Since the rose returns to 'normal' does that mean that it must be the virus that is changing some way?

for instance... does a rose like peace that its infected at some point have a window within which it will be viable... say 50-60 years ... before the virus simply completely adapts

its probably far fetched.

i am also curious though about the pressure that mosaic viruses put on a species in general... does the presence of a mosaic virus influence the propagation cycle in a particular direction? if it takes maybe an average of 50 years for a mosaic virus to kill a certain species, does that place a selection pressure on the offspring related to to that time window?

of course if the virus doesn't mutate quickly at all, that would be moot right? it would have to be some damage that the plant was sustaining.


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RE: What's the best nursery free of Rose Mosaic virus?

Darn, I got virus indexed for the flu last year and, well, you guessed, I had it anyway. Are roses the same? Roses Unlimited roses are greenhouse grown, so unless their roses were contaminated by other means and they were received from Dr. Manners and were not contaminated by another rose in their nearby vicinity, then they are not contaminated, but .... I digress, I had the flu last year after getting the vaccination.


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RE: What's the best nursery free of Rose Mosaic virus?

well, there are many different flu viruses (or is that virii?)


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RE: What's the best nursery free of Rose Mosaic virus?

Judderwocky I was not going to post on this thread again, and will plan to stop after this, realizing all "H - E - double hockey sticks" is likely about to erupt. But good questions.

"Deterioration" in a rose is one of those things that has never been proven to exist, let alone to have a cause. I do believe in it, although I think the reasons often given (especially "over-propagation") are without merit. And even among those who think such deterioration may be viral, no one has ever pinned it on any of the specific viruses causing rose mosaic. Rather, there are many "cryptic" viruses in roses, as in most plants, which are "symptomless" in the sense that you can't just look at a plant and see it. Nevertheless, such a virus could perhaps cause the cultivar to be less vigorous, flowers to be of lower quality, etc. Of course that's not to say that it is NOT caused by one of the viruses that also cause mosaic; just that we don't know that.

What we DO know is that some varieties that were widely claimed to have deteriorated ('Peace' is the classic example, and also 'Reine des Violettes') are rampantly more vigorous, with bigger, more colorful blooms, after heat therapy than they were before. Yes, we removed mosaic in that process. But what else might we have removed? We just don't know. In any case, the heat therapy seemed to have a beneficial, long-term effect. My theory (for which I have no direct proof) is that we have knocked out something viral.

You also asked about mosaic's effect, long-term, on a species. If you mean rose species, that's probably not a useful question, since the disease is believed (by all but one person) never to be contagious, by any means other than human activity, in the field (by "human activity" I'm including planting them in very close proximity -- inches -- a way one would never grow a rose in a garden). So yes, the point is moot. Our garden experience has been that mosaic-infected plants sometimes do decline to the point of death, but that others may live many years in apparently good health. Yet they'll always test positive for the virus. So I don't think we can generalize about any such long-term effects.

As for mutant forms of the virus -- I'm sure they must mutate, just as does flu virus. On the other hand, in our short life span on this earth, no one seems to be seeing that either -- plants that can be traced back to the old Roses of Yesterday and Today nursery always carry that same mild strain of PNRSV that can be used as a fingerprint for that nursery! (I've wondered where they got it, originally). There's also a Florida nursery with their own strain of PNRSV that is consistently testable.

And Patricia -- perhaps you were joking -- but "indexing" is a method of testing to see if a virus is present, for the purpose of diagnosis. It is not in any way like a flu shot, which is an actual dose of the virus, killed or weakened, to which your body then makes antibodies. A very different scenario.


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RE: What's the best nursery free of Rose Mosaic virus?

Of course, Malcolm, I was...and I know the difference, but I was also trying to say that we can never know when our body is free of or our rose if it has been exposed. If you index a rose and you send it off for resale, who is to say that it does not come in contact with another sick rose and get infected although it was virus-free after the indexing and there is no guarantee that even with a vaccination (which we do not yet have for roses) that it will not come in contact with and be "infected by" another rose, not even of the same name. We have become a susceptible society, roses and people. So upwardly mobile and so worldly, we are.


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RE: What's the best nursery free of Rose Mosaic virus?

A scientifically studied factor contibuting to variation in the properties of a variety is "Topophysis" (the influence of the position of axillary buds along the shoot on bud and shoot growth, fresh biomass accumulation, and flower development).

http://www.ncbi.nlm.nih.gov/pubmed/10506462
----------------------------------
The following 2 links lead to popular press (not reviewed scientific papers) articles by "2 big names in roses" on the subject of deterioration.

http://www.plant-care.com/do-roses-grow-old.html

http://paulbardenroses.com/McCann001.html

Here is a link that might be useful: reviewed scientific paper


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "As for mutant forms of the virus -- I'm sure they must mutate, just as does flu virus. On the other hand, in our short life span on this earth, no one seems to be seeing that either -- plants that can be traced back to the old Roses of Yesterday and Today nursery always carry that same mild strain of PNRSV that can be used as a fingerprint for that nursery! (I've wondered where they got it, originally). There's also a Florida nursery with their own strain of PNRSV that is consistently testable."
----------------------------------
H.Kuska comment: Mutations are point events. The most probable situation is that only one virus will have a given mutation at one time. Thus the fact that the observed viruses in a given variety of plant that originated from a given nursey appear to always test the same says very little to nothing about whether virus mutations have occured in that variety. Particularly, since most mutations are negative mutations such that the mutated virus will not be as effective as the original. (At the other extreme, a "super positive" mutation would possibly kill the original plant and not be of further interest.)

As an example of what has been done, a limited amount of research has been published on the rate of mutations of RNA plant viruses (PNRSV is an RNA virus).

http://rsbl.royalsocietypublishing.org/content/5/3/394.full.pdf

-------------------------------------------
See Figure 4 of the following link for a "map" of different strains of PNRSV identified up to 2009.
http://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS-93-6-0599

See the explanation for the origins of the "map" on the top left of page 603.

Here is a link that might be useful: reviewed scientific paper


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RE: What's the best nursery free of Rose Mosaic virus?

I recently read a "reviewed scientific paper" on why zebras have stripes. It's a good paper. Good scientists. Good work. Excellent writing. Thoroughly peer-reviewed. We ought to believe it. Yet it is irrelevant to this conversation. Just as topophysis (a well-known phenomenon in many plants, including roses, observed rather thoroughly by nurseries over the years) is irrelevant to any discussion of viral diseases or, for that matter, cultivar deterioration, which it cannot explain, for several reasons (which I'd be happy to discuss elsewhere with those interested, but refuse to continue to fan the flames of silliness here). And yes, any first-semester plant science or biology student knows that mutations occur at single points in single viruses. Again irrelevant to the current conversation, where we're talking at least billions of replications in many thousands of plants, over many years.

I really am trying to stop replying to all the blather, and wish this thread would just die a quiet death. But the teacher in me wants to be sure other readers will recognize blather when they see it. So I'll risk a bit more masochism for that cause.


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RE: What's the best nursery free of Rose Mosaic virus?

Malcolm, you are the one that stated: ""Deterioration" in a rose is one of those things that has never been proven to exist, let alone to have a cause. I do believe in it, although I think the reasons often given (especially "over-propagation") are without merit."
---------------------------------------
Notice that he used the statements:

"never has been proven to exist, let alone to have a cause"
ALSO
"without merit".

This is a forum. If someone makes a statement, he/she can expect to have the statement challenged if someone else feels that it is not accurate.
--------------------------------------
Regarding the statement: "Again irrelevant to the current conversation, where we're talking at least billions of replications in many thousands of plants, over many years."
------------------------
H.Kuska comment. Yes, that is my point. Your experience with a very limited number of plants ("On the other hand, in our short life span on this earth, no one seems to be seeing that either -- plants that can be traced back to the old Roses of Yesterday and Today nursery always carry that same mild strain of PNRSV that can be used as a fingerprint for that nursery!") Notice that you say "no one" I suggest that what you actually can say scientifically is that you did not.
My actual statement was: "Thus the fact that the observed viruses in a given variety of plant that originated from a given nursey appear to always test the same says very little to nothing about whether virus mutations have occured in that variety."


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RE: What's the best nursery free of Rose Mosaic virus?

The following statement was made: "If you mean rose species, that's probably not a useful question, since the disease is believed (by all but one person) never to be contagious, by any means other than human activity, in the field....."
______________________________
H. Kuska comment: Please notice the statements: "by all but one person" and "never". Is this a scientifically accurate statement? I expect that many of the advanced rose growers are familar with Dr.Austin Hagan, Extension Plant Pathologist, and Professor at the Department of Entomology and Plant Pathology at
Auburn University since he has done considerable rose disease blackspot research. The link below is to a 2007 article coauthored by him. Please note the following: "Pollen transmission of one virus, PNRSV (prunus necrotic ringspot virus), is suspected due to the slow spread of the disease within roses."

Here is a link that might be useful: Auburn University 2007 article


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RE: What's the best nursery free of Rose Mosaic virus?

Often scientists are able to use well studied plants to develop models for the behavior of less studied plants. Concerning virus mutations, earlier I presented a "map" of known PNRSV mutations. The following paper attempts to explain "why" all mutations do not simply disappear on their own. I interpret it as saying that if the mutation does a better job of overcoming the plant's immune system (or another plant that is similar that it can come into contact with) it will multiply/compete. Of particular interest is that if the other plant is a hybrid, it may be easier to infect i.e. the hybrid has a broken down (less effective) immune system. "Remarkably, either of two genes was sufficient for infection of some citrus hybrids."

"These findings suggest that CTV acquired multiple nonconserved genes (p33, p18, and p13) and, as a result, gained the ability to interact with multiple hosts, thus extending its host range during the course of evolution."

Here is a link that might be useful: 2011 National Academy of Sciences Paper


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RE: What's the best nursery free of Rose Mosaic virus?

If you are considering utilizing a rose with a known virus infection, you may find the following very recent (Posted online on 10 Feb 2012) scientific paper (with a USDA co-author) of interest .

http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-11-11-0928-FE

"Some of the viruses associated with desirable effects in ornamental plants include virus species that are capable of causing disease in economically important crops. Therefore, regulatory procedures may have to be implemented with some of these viruses to minimize their dissemination."

Here is a link that might be useful: Posted online on 10 Feb 2012 reviewed scientific publication,


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RE: What's the best nursery free of Rose Mosaic virus?

It's like talking to a wall. I totally give up. It's pointless and worthless. The point is always missed utterly, and obfuscation sets in, twisting everything said. Enough.


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RE: What's the best nursery free of Rose Mosaic virus?

thanks for the info Malcom!

Very interesting. :)

If anybody is interested in a good site for learning more about viruses in general... I listen to the virology podcasts...

mostly human viruses, but occasionally they touch on viruses that affect other things

Here is a link that might be useful: virology with Vincent Racaniello PhD


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RE: What's the best nursery free of Rose Mosaic virus?

Dec 04, 2007 comment in a Rose Hybridizers Thread by Ph.D. David Zlesak who is currently working on rose virus research.
Please particulary note his concluding recommendation:
"In the meantime I think, if possible, we should remove plants with obvious signs of infection and try to use good sanitation and pruning practices."

-----------------------------------------------

"This is a very interesting line of thought. Elisa isn't always that accurate depending on ones threshold for color (background color can vary depending on things inherently in the rose tissue which can be partly cultivar dependant) and how concentrated the virus is. I help Ben Lockart on his rose virus projects. PCR tests are more sensitive. If you know the sequence of the DNA or RNA (depends on the type of virus of course) of a virus and identified selective primers one can determine if the virus is present even at relatively low concentrations in tissue. The presence of an amplified DNA product (through PCR) that is the appropriate length between the primers for your virus would be present or not when the sample is ran out on a gel and DNA fragments are separated according to size. If it is an RNA virus, one converts it to cDNA and go from there. It takes careful DNA or RNA (depending on virus) extraction and more skill and different lab equipment than in a typical Elisa lab, but is very possible in a modern molecular biology laboratory to do this work.

There are many more viruses out there in roses and relatively little has been done to identify more in many decades. There are different types or classes of viruses among what Ben is identifying and documenting. It takes someone with electron microscopy skills (dying art) like Ben to isolate and observe the shape and size of virus particles from tissue. In order to make significant headway it takes someone, also like Ben, that from that can work with different primers common to classes of viruses to see if there are amplifed regions with the primers and sequence those fragments to see what characterized viruses these sequences most resemble. Sometimes it may be a virus already documented in another crop, or a new one with relatively little similarity to what has been characterized in any crop. Transmission studies are important to understand that the symptoms associated with a virus actually are caused by that virus. One way to do so is to take virus-free roses and graft or otherwise innoculate it to get the virus in it. Mode of effective transmission can be documented and is also associated with class of virus and how it moves in the plant as well. One can then watch for symptoms to develop on the virus free rose (hopefully of the same cultivar it was originally found on so you know it should display the symptoms if it actually is the causal agent). One can sequence more of the virus and use PCR and electron microscopy to learn if the virus free rose is now infected with that virus and innoculation was successful, even before symptoms may appear. Symptoms may be transient as it takes particular environmental conditions before it is expressed. At some point a rabbit can be injected with the virus to generate antibodies for Elisa tests. The sensitivitiy of the antibody can be tested to see how specific it is and useful for Elisa. Some of the hosta antibodies and other antibodies used by Agdia and other companies were provided by Ben.

There are many different kinds of viruses. Some can survive in the soil outside of the host for quite a while, while some die soon after being removed from a host. Some are "cryptic" and seed transmitted and do not supposedly reduce much vigor in the host. Some express more severe combinations in the presence of other viruses. There is a lot more to learn. Some are mechanically transmitted, while others are not because they are mainly in the phloem and the phloem plugs up fast when cut and even if some virus got at the cut it typically doesn't enter then.

I don't think virus is a hopeless battle. I think eventually we may need to change our mind about "virus-free". I hate that some nurseries claim this about their roses. They have "virus indexed" roses using Elisa for the few major, characterized viruses out there. I think we'll eventually accept some viruses as not too harmful and not worry too much about them, while for others there is more concern. Some viruses will be very difficult to impossible to clean up even with heat treatment and meristem culture because of their nature and how they develop and spread. For instance, there is a class of crytic virus that is seed transmitted. It is in every cell, even those in the growing point from the beginning. It would be relatively rare to find a seedling from an infected maternal parent that did not get it. There may be a rose virus that is like that. It takes time and money to make progress with these viruses and Ben is working on it out of the kindness of his heart without funding in his spare time. I should encourage him again to apply for some of the limited ARS research funds.

In the meantime I think, if possible, we should remove plants with obvious signs of infection and try to use good sanitation and pruning practices."

http://www.rosebreeders.org/forum/read.php?2,14137
----------------------------------------------------
Rose hybridizers can have a significant advantage if they make an attempt to understand as much of the biology of roses as possible in order to be successful at producing new roses (rather than the classic "trial and error" approach).
As an example of the above please see the link below which gives a discussion of stripes in roses.

http://www.rosebreeders.org/forum/read.php?2,20475,page=1

I particularly suggest that you read the Jim Sproul post on March 21, 2009 which includes: "For whoever might be interested, I wrote an article several years ago following a discovery of a striped sport branch on a 'Lynn Anderson' plant that was growing adjacent to a 'Scentimental' plant( http://sproulrosesbydesign.com/stripes.htm ). What I think happened, is that a stray "CHANCE" pollen from 'Scentimental', where the transformed DNA released viral particles that upon pollination of the 'Lynn Anderson' bloom, "infected" it. I then think that what happened is that the virus did not move very far into the plant before it reinserted itself into the host 'Lynn Anderson' plant DNA so that it didn't "infect" the entire plant. The branch that contained the stripe mutation did come from a distal tip of the" (see link above for the rest)

Jim Sproul is a medical Doctor and the present Director of the Rose Hybridizers Association. He has a series of "spotted roses" - "Eyeconic" that are now being introduced.

http://www.rosebreeders.org/forum/read.php?2,36581

Here is a link that might be useful: discussion of stripes in roses


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RE: What's the best nursery free of Rose Mosaic virus?

LOL. ...

You are like a parrot. You don't understand anything of what you are saying.

You are the quintessential stonefruit.

Have you ever suspected that you might be infected with RMV?


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RE: What's the best nursery free of Rose Mosaic virus?

"The standard immunological test (ELISA) did not detect the PNRSV infection, highlighting the greater sensitivity and value of molecular tests"

And in another section:

"Electron microscopy of several samples has not revealed any virus."
--------------------------
Yes, these are not rose tests, but the information contributes to what scientists know about the limitations of prior "state of the art" methods and presently preferred methods of plant virus checking.
------------------------------------------

Here is a link that might be useful: November 2011 Australian report


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RE: What's the best nursery free of Rose Mosaic virus?

The paper in the link below is titled: "Symptom Remission and Specific Resistance of Pepper Plants After Infection by Pepper golden mosaic virus"

We are fortunate that the complete paper is available to the public.

This experiment reports on a study where only a single leaf is infected. Thus, it differs significally (in my mind)from what happens when a plant is grafted to a virus infected rootstock but appears (to me) to be similar to what happens when a plant is infected by above ground natural infection (sort of point contact) routes.

Points of interest: "However, a general view could be expressed as follows. Plant defenses (e.g., RNA silencing and possibly others) initially triggered in the symptomatic tissue (S) due to the high levels of viral RNA are responsible for reducing viral RNA in the emerging R1 leaves. Low concentration of viral RNAs results in a lower level of viral replication, which results in a viral concentration below a threshold required for symptoms. Low DNA titer, in addition to the still-acting PTGS, results in low expression of viral transcripts."

ALSO and potentially the most interesting aspect (to me) of this paper is the following:

"In the system reported here, the recovered tissue failed to be reinfected by the same geminivirus"

Also of interest (to me)is their finding that with infections with 2 different viruses, the immune system could not defend the plant to the level that the symptoms were not observable.

Here is a link that might be useful: 2007 reviewed scientific paper


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RE: What's the best nursery free of Rose Mosaic virus?

I really don't know why Gardenweb has deleted my question that I posted in the "La Ville de Bruxelle" thread. After all, that thread was about collecting seeds and pollinating.
Since this discussion is about viruses, I really hope the experts on here can tell me if I cross a healthy rose with a rose that appears to have a virus, will both the offspring and the healthy rose be infected? I want to know this because I am planning on hybridising my roses soon and I certainly don't want to infect the healthy roses that I have.


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RE: What's the best nursery free of Rose Mosaic virus?

Jumbojimmy, It's been established that virus infection can be transmitted via pollen in certain fruit trees, including apples (which are related to roses).

In roses per se, however, it's my understanding that the only PROVEN means of transmission is through vegetative propagation using either infected root stocks or bud wood. Crosses using an infected pollen parent can be expected to produce virus-free seedlings. If vegetative propagation is, in fact, the only vehicle for transmission in roses, then the same would hold true even if both parents are infected.

Your question about infecting a healthy seed-bearing parent with pollen from a virused plant should therefore be of no concern.


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RE: What's the best nursery free of Rose Mosaic virus?

jumbojimmy, I suspect you are going to regret asking that question in context of this thread!


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RE: What's the best nursery free of Rose Mosaic virus?

The key word in the hybridizing question answer above is "proven". Scientifically "proven" requires an experiment with a statistically sufficient number of plants and controls. One cannot determine what number will be statistically sufficient without having some idea of the % spread. Here one looks at the literature. 1 % virused multiflora seedlings have been observed in 2 batches of seeds in an English publication. The French observed 1 % spread which could not be statistically separated from zero. Hybridizers have occasionally (but rarely) observed virus symptoms on their seedlings but did not test them.

In another thread I examine the statistics: "I am interested in what is the natural spread of rose viruses. In designing any experiment one normally calculates the number of samples required to obtain a result that has a 95% confidence level. I think the results of this type of calculation for rose virus spread are interesting.
If the natural spread in a field is 1% a year and one checked the field at the end of one year, one would have to examine 2377 plants to be able to report the results as having a 95% confidence level (1.0 +/- 0.4)%.
If the natural spread in a field is 4% a year, and one checked the field at the end of one year; one would have to examine 9220 plants to be able to report the results as having a 95% confidence level (4.0 +/- 0.4)%. To be able to report a (4 +/- 1)% spread, the number of plants should be 1475. To be able to report a (4 +/- 2)% spread number, one would need to examine 369 plants. To be able to report a (4 +/- 3)% spread number, one would need to examine 164 plants."

http://www.uk.gardenweb.com/forums/load/roses/msg071057108109.html?17

The Florida spread experiment used 10 plants. The most recent California experiment used: "Dr. Huey included 60 virus-negative" and "R. multiflora included 20 virus-negative".
http://forums2.gardenweb.com/forums/load/roses/msg0710595423501.html
The Florida 10 plants were looked at for 3(4?) years; the California plants were examined for 5 years. The simplist correction for a multi year trial is to assume that they are equivalent to a one year trial with 30(40) and 400 samples. Still not enough to "prove" lack of slow (1 to 2 % spread). In fairness to the California study, they did not interpret their results as "proving" no above ground spread. They "proved" below ground spread.
------------------------------------------
I now understand the limitations of ELISA testing and the contribution of the immune system. For something involving "point contact" spread at least PCR will probably be needed, of course electron microscope examination would be the ideal choice.
Also, since the immune system is temperature dependent; I predict that the results will be different under cool climate conditions than will be found in southern warm climates. Please read my link below.

Here is a link that might be useful: link to my web page treatment of this point


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RE: What's the best nursery free of Rose Mosaic virus?

Jimmy, I understand your concern and have shared your desire not to willingly infect "clean" roses through breeding. Realistically, you have little control over any of it. IF it eventually proves to be possible to easily infect roses through tainted pollen, it would likely happen even without your efforts. IF you could be sure of every rose you touch not being infected, you might have a chance. It's a documented fact that infected plants can grow perfectly well for decades without showing any symptoms of infection. Unless you have the resources and patience, and can find somewhere to have all of your roses tested for infection, you can't be sure none of them are.

All you can really do is to resist using plants which show obvious symptoms; practice good plant hygiene whether there is any evidence of spread via tools or not; and hope for the best. I don't think you have sources for VI treated and tested material in Australia, do you? Barring sources for certified tested stock, it's really something you can't do much, if anything about, so just make your crosses and have fun doing them.

The strongest evidence is the percentage of 'clean' stock is significantly greater now than it was thirty-five years ago; and that little, if any, transmission in roses is possible through breeding or tools. Should you choose to bud your seedlings, make sure you obtain root stock that is verified uninfected or every effort you've made may well have been in vain. Perhaps raising your own from seed might afford you that luxury. Propagating only through rooting cuttings will permit you to prevent infection from "dirty root stocks". I'm afraid that's about the best you can do, so don't worry about it. Just explore and have fun doing it. Kim


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RE: What's the best nursery free of Rose Mosaic virus?

Based on the information in the USDA paper and the Australian Biosecurity report, I suggest that universities that are interested in rose virus research funding stress the importance of funded rose virus research in the following areas:
1) obtaining knowledge concerning what viruses do infect roses
and
2) developing reliable, easy to use, methods to detect these rose virus
and
3) developing reliable, easy to use deactivation methods for each known rose virus
to prevent roses from being a source of contamination to food crops.

i.e. It appears to not really be that important in the grand scheme of things to know if roses infect each other at a rate of 2, 1, or 0.1 percent per year. What appears to be important is to develop methods to remove (decrease to a minimum) the possibility that roses will infect our food plants.


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RE: What's the best nursery free of Rose Mosaic virus?

Probably, and isn't that the most beneficial? As resources further decline and greater pressures placed on them, food is much more important than "ornamentals". Statistics show in a little over the past decade, the American rose industry sales have declined more than 60%, from roughly 50 million to fewer than 18 million plants. Demand for food increases daily. Where else would you expect the shrinking budgets to be spent? Kim


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RE: What's the best nursery free of Rose Mosaic virus?

In case someone wonders if a rose virus has been shown to infect a food plant, from my 74 year old memory I seem to remember a number of such reports in the literature, but I will just report one here where the full paper is available to the public. It reports which strains of PNRSV will infect cherry (P. avium). In this paper strains R1, R2, and R3 came from roses.

See page 20 (Photo 9).

Also of importance to understand is that not all PNRSV isolates were able to cause infection (I suggest that the reason is because the immune system of the cherry was "fine-tuned" to only specific isolates).

One can ask" so what, if the rose virus only causes 1 or 2 % spread in the new host and minor growth damage like it does in roses; it will be no big deal.
Our colds are no big deal, yet they killed the American Indians because their immune systems were not "tuned" to the cold virus. There is one "theory" that polio was initially a plant virus (due to similarity in structure). You know what damage it caused.

Thus there is a real possibility that a species transfer virus can cause real economic problems.

Here is a link that might be useful: 2007 reviewed scientific paper


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RE: What's the best nursery free of Rose Mosaic virus?

To head off the comment: but I was taught that plant viruses do not cross over to animals, see the National Academy of Sciences 1999 paper link to below as one example. It has been cited 140 times by other reviewed scientific papers.

Here is a link that might be useful: National Academy of Sciences 1999 paper link


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RE: What's the best nursery free of Rose Mosaic virus?

Perhaps I should just stay shut up and let this pass. On the other hand, by writing this post, I'll undoubtedly elicit the remaining number of zany replies needed for this thread to reach the magic 100 and be forced to die!

One wishes for some Twilight Zone music here -- the place has gotten so other-worldly weird. We started out with a simple question about nurseries, and now we have mutant plant viruses killing off us humans. I suggest we step back a bit, take a deep breath, and look at reality:

1. We have a chemist (perhaps a very good chemist?) with precisely zero knowledge of plant virology, lecturing the rest of us on plant virology. This person demonstrates daily an utter lack of understanding of any aspect of plant viruses. He ignores the valid researchers, or misquotes or misinterprets them. He presents vast numbers of good, peer-reviewed references, absolutely none of which ever support his bizarre claims.

2. He creates straw men in order to insult and denigrate the people who understand the subject in question. In this case, we have post after post after post about lack of statistics (when in fact we have hundreds of millions of plants in gardens everywhere, over more than 80 years, without the first case yet of documented spread of rose mosaic in a garden).

3. He points out that the "problem" the real researchers have is that they live in climates too hot to understand the problem, or they use poor methods of diagnosis, and so they just don't see the horrible spread of this disease. Yet he ignores, completely, the fact that NO ONE ANYWHERE has EVER documented spread of PNRSV or ApMV in roses, via pollen, insects, nor ANY other means than grafting (man-made or natural), and the natural grafts have been demonstrated in one location only, in closely planted plants.

4. He looks for means of explaining the "slow spread" of the disease, when in fact there is precisely zero evidence that any slow spread is occurring at all. Why try to solve a problem that does not exist?

5. The supposedly dreadfully poor methods that have been used for years, for indexing, have in reality given a 100% perfect record of accuracy. No one ever, anywhere, has demonstrated rose mosaic in a rose that we've declared clean. Not one. No suggestion even, of it, other than from this one person. Again, there is not a problem here. There is not a suggestion of a problem here. It's all made up by one non-pathologist who is on his soap box, trying to deceive us. Of course each method if indexing has its weaknesses. We all know that. We all deal with that. We understand that situation completely, FAR, FAR, FAR better than this one writer has any clue of.

It seems to me that we can choose to follow one of two camps:

1. All real mosaic researchers are without a clue; they are unintelligent idiots who need to be lectured as small naive children.
2. Mosaic is killing the earth. We will all now die of polio or worse, which we will catch from our roses.
3. Mosaic spreads daily, via pollen, seeds, bugs, and likely garden pixies, so that within minutes, all of the roses on the earth will be destroyed, then we'll all die of the polio.
4. All of the methods we've used to test for virus have been faulty and so no one has any clue about what is or is not infected.
5. Methods used by people who don't deal with roseviruses will, by definition, always be better than methods used by actual virus researchers. And rose virus researchers would never even think of looking at the literature on our subject -- we feel the deep need to wait for chemists to read it for us and then explain it to us here.
6. All viruses behave in exactly the same way -- they all cause rose mosaic and the common cold and HIV-AIDS. We're all going to die now.

OR

We could follow a different view of the facts:

1. Rose mosaic is a very well-understood disease that has been rather boring, in that it has not presented us with any big surprises in many years.

2. The only thing even slightly surprising about it in the last decade was the discovery that roses planted in very close proximity do sometimes form natural root grafts, and as expected, the virus can then move through that root graft.

3. Except when very closely planted (inches), there is not the slightest shred of evidence that rose mosaic (defined by virtually everyone as PNRSV, ApMV, and AMV and excluding all other viruses, none of which are present in significant populations in this country anyway)has ever spread naturally, by any means at all. Never by pollen, never by seed, never by pruning equipment, never by ANY method other than grafting. Not once. Not ever. Any claims to the contrary had better be backed up by true evidence, not the hogwash we've been reading here. And of course they won't be -- such evidence does not exist.

4. Heat therapy is extremely effective, with a success rate of precisely 100%. Indexing methods that have been used for the last 30+ years are also extremely effective WHEN USED CORRECTLY, (and we all do), so that there is not a single documented case (note that -- not one documented case) of a plant once determined to be mosaic free later showing up with mosaic. That is equally true for cold climates as it is in hot climates. Of course it's likely that some nursery, at some point in history, accidentally sent out the wrong plant, so that a customer received an infected plant when they thought they were getting an uninfected plant. Such mistakes are bound to occur. But note that that has nothing whatsoever to do with a failure of heat therapy nor of the indexing methods used. Their record is flawless.

5. The claim that the disease behaves differently in cold climates is simple insanity. Obviously, we all know (and have known for decades) that virus titer rises and falls with temperature. But the suggestion that hot-climate people are just ignorant because they live in hot climates is ridiculous. Notice that there is just one cold-climate person who disagrees with that statement, and it is he who I'm refuting here. All of his countless references to "real, scientifically reviewed papers" do not support his claims. In every case, they either deal with a different virus, a different crop, or if they do deal with the viruses causing rose mosaic in roses, his interpretation of their results is not what they were actually saying. 100% of the time.

6. There really, truly is no problem here! We understand mosaic. We cure plants of rose mosaic. They stay cured forever. We are not seeing any spread in the field at all. No one is.

Wow, I wish we had Twilight Zone music...


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated:
"It seems to me that we can choose to follow one of two camps:

1. All real mosaic researchers are without a clue; they are unintelligent idiots who need to be lectured as small naive children.
2. Mosaic is killing the earth. We will all now die of polio or worse, which we will catch from our roses.
3. Mosaic spreads daily, via pollen, seeds, bugs, and likely garden pixies, so that within minutes, all of the roses on the earth will be destroyed, then we'll all die of the polio.
4. All of the methods we've used to test for virus have been faulty and so no one has any clue about what is or is not infected.
5. Methods used by people who don't deal with rose viruses will, by definition, always be better than methods used by actual virus researchers. And rose virus researchers would never even think of looking at the literature on our subject -- we feel the deep need to wait for chemists to read it for us and then explain it to us here.
6. All viruses behave in exactly the same way -- they all cause rose mosaic and the common cold and HIV-AIDS. We're all going to die now."
-----------------------------
H. Kuska comment. Those are not my statements. Please see the following link:
http://en.wikipedia.org/wiki/Straw_man

Scientists can do research in a field by doing experiments and/OR by doing literature research and "connecting the dots". I agree that I appear to be the first to recognize that the research on plants having a temperature dependent immune system offers a probable explanation for some of the perplexing observations reported with roses. I have communicated my findings in personel e-mails to scientists that have indicated an interest in this area (some do not reply, others including what I consider some of the important ones not only reply but keep me up to date on their work), by developing web pages, and by participating in forum discussions.
I have attempted to document my statements. I am particularly interested in any scientific based comments on my specific statements (by scientific, I mean if at all possible please document your statements).

I am a physical chemist, our training is explained below.

My interest in viruses is partially based on my being a polio survivor. My older sister contacted the disease at the same time and died. A neighbor girl (2 doors down) also got it at the same time. Also, my father was sent home from the army to die from the infamous flu that wrecked havic then (world war 1). He survived but had permanent health damage. He was a college graduate in agriculture and taught at the high school level. Of course he was also interested in virus problems and even attempted sulfur based experiments (you can guess what my mother thought of that).

Here is a link that might be useful: explanation of a physical chemist


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated:
"As used by gardeners," rose mosaic in the USA is well more than 99% PNRSV, substantially less than 1% ApMV, and so exceedingly much less than 1% all other viruses combined as to be completely ignorable and irrelevant."
------------------------------------
H.Kuska comment: Please note, no documentation.

Scientists from Cornell University published a paper "SYMPTOMATOLOGY AND OCCURRENCE OF APPLE MOSAIC AND PRUNUS NECROTIC RINGSPOT VIRUSES ON ROSE IN NEW YORK".
They reported: "The proportion of PNRSV (78.5%) in ELSIA positive samples was much higher than that of ApMV (16.)%). The average frequency of detecting the presence of both viruses in ELSIA positive samples was 5.4%(Table 2). It is not known whether this 5.5% average represented a true mixed infection of two viruses or represented the presence of intermediate serotypes (Casper, 1973) or both...........................Perhaps PNRSV may cross protect against ApMV despite the mode of transmission."

----------------------------------

Their data base was 794 leaf samples that were collected based on showing visible symptoms.

According to Google Scholar, the above paper has been cited by 10 papers.
-------------------------------

Here is a link that might be useful: 1988 New York Cornell research paper


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RE: What's the best nursery free of Rose Mosaic virus?

Ah, the Wong paper -- the same one that claims 'Nearly Wild' is resistant since they never saw symptoms and couldn't find any virus in it, while it is symptomatic and easily tests positive everywhere else. (We've never been able to find a clean one in the trade.) That alone makes that entire work highly suspect, and other virus researchers have considered it unfortunate for the past 24 years.

Documentation is a good thing when it exists, when it is reliable, when it actually says what the writer claims it says, and when there is a real controversy needing backing up. We've been seeing a rather amazing amount of "documentation" in this thread, virtually none of which supports what the writer is claiming. That misuse of documentation is commonly called "lying."

And if documentation is needed for every statement here, why are we having this conversation at all, since there is no documentation to say that rose mosaic is different in cold climates, that it is spreading by any means, or any of the many other claims being made by this one writer? Certainly none of the documentation provided so far has supported any of the bizarre claims.

Still wanting Twilight Zone music...


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RE: What's the best nursery free of Rose Mosaic virus?

Regarding Nearly Wild, I have no problem with the Cornell paper statement concerning their observation. I feel (from my reading the scientific literature) that there can be expected to "POSSIBLY" be a difference between an immune system being able to fight off a spot type one time infection and being able to fight off an infection caused by being grafted to an infected rootstock. I feel that your observation "MAY" simply mean that all of the plants that you were aware of were initually infected by "dirty" understock. See the paper introduced by me on Wed, Feb 15, 12 at 19:45. I also recognize the "POSSIBILITY" that PCR and, if not it, than an electron microscope examanination "MAY" find that the Cornell samples were indeed infected. Please see my discussion of what they actually stated below and recognize the meaning of the word: "APPEARED"

The Cornell researchers clearly state their inoculation method: "Patches of leaf tissue were inserted under a flap a flap cut in the stem at the site of stem buds of the receptor plant. Grafts were firmly wrapped with parafilm strips." If a scientist wanted to dispute another scientific papers observation, the experimental conditions should be duplicated. Please notice that they stated "Only Nearly Wild appeared to be resistant to both viruses because ......". (I wish I could put "APPEARED" in bold type.) Please notice the difference of the above actual statement and the use of the verb "IS" statement: "claims 'Nearly Wild' is resistant". i.e. They did not claim what was stated that they claimed.
---------------------------------------
The Cornell paper was cited by 10 other more recent papers. Looking at citations can be a useful scientific step if one "feels"/"suspects" what was stated in this thread about the paper: "That alone makes that entire work highly suspect". Was there communication of concerns to Professor Horst? At least in the scientific circles that I was familar with, valid scientific criticism is welcome.
----------------------------------------
My most recent statement regarding documentation was: "(by scientific, I mean if at all possible please document your statements)". That is different than: "if documentation is needed for every statement here,...". Please notice the words "IS" and "EVERY". The comment is not a comment about an actual statement. Please read the straw man link given earlier. An earlier statement of mine concerning documentation was: "I find it very disappointing that someone feels that statements about others can be made and not documented." This is from a different context (please note "ABOUT OTHERS". When someone states someone said "such and such" and does not provide the actual quote so that the reader can put the statement into context and/or see if the person actually even ever said that; yes, I am very disappointed.


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RE: What's the best nursery free of Rose Mosaic virus?

Post 92. 8 to go... The insanity continues.

Twilight Zone Music PLEASE!


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RE: What's the best nursery free of Rose Mosaic virus?

Now in rereading this I must say I'm puzzled -- how could we easily and consistently find virus in a rose by the faulty, old-fashioned, highly flawed, ignorant method of ELISA in a hot climate (where we're all ignorant, haven't a clue how real science works, are unfamiliar with statistics or the peer-review process, and are generally slovenly swine), whereas "real" scientists at Cornell (I believe their climate would not be considered hot, and therefore, by definition, they must be intelligent and well-trained) were unable to find it? That just doesn't make sense, considering what we've been lectured about here and in countlessly many other posts over the years.

Of course I jest. I hold Horst's program in highest regard. But in this case they were in error. I merely point out that the interpretation here seems quite odd to me. In reality, I suspect their plants were not infected, and no PCR nor any other method would have found the virus. Again, we are being lectured on a problem that does not exist, since ELISA, Shirofugen, and 'Mme. Butterfly' are HIGHLY accurate and reliable and repeatable methods of indexing with a precisely zero failure rate. Yes, certainly PCR can detect a lower titer. But since titer rises within hours of cooling a plant off, why not just do that, as we (and all other real virus researchers) have known to do for decades! Once again, we're hearing solutions to a problem that exists only in the mind of one writer, a writer who, so far as we know, has never actually done ANY research with rose viruses himself, and who continues to misinterpret the work of others.


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RE: What's the best nursery free of Rose Mosaic virus?

I assume most of the advanced readers are familar (or can look up) Professor Horst's credentials. Now what about the student, Sek-Man Wong, who's Ph.D. Thesis was the basis of the publication?
First was Dr. Sek-Man Wong familar with ApMV? Judge for yourself. Please see the 1993 reviewed scientific research paper that he and Professor Horst published.

--------------------------------------
Has Dr. Wong had addition contributions to plant virus knowledge and was he successful in his career?

http://www.dbs.nus.edu.sg/staff/wongsekman.htm

AND

http://www.dbs.nus.edu.sg/staff/cv/wongsekman.pdf

Please put the following (including the quotes) into Google: "A research-intensive university with an entrepreneurial dimension, NUS is ranked consistently as one of the world's top universities."

Here is a link that might be useful: 1993 Wong and Horst ApMV paper


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "Yes, certainly PCR can detect a lower titer. But since titer rises within hours of cooling a plant off, why not just do that, as we (and all other real virus researchers) have known to do for decades!"
--------------------------------
I have documented that EISA tests of PNRSV in non rose plants in the field did not find as many infected plants as PCR did. With the first order assumption that all of the plants were exposed to the same general temperature variations, why did they all not have the same virus concentration when measured? I suggest that the answer is that the above reasoning is not taking into account the efficiency of each plants immune system. I have documented that there are reviewed scientific papers that report that even within an individual rose plant, not all of the leaves show infection either visibly or by ELISA.

I should give further credit to the 1988 Cornell paper. At that time it was common to hear rose virus statements similar to: "Cuttings from an infected plant will be infected - no matter what portion of the plant they were taken from. The disease is systemic: The entire plant is infected, whether visible signs of the disease are present, or not." see:
http://www.goldcoastrose.org/
The Cornell paper stated: "Virus distribution in apple, plum, and cherry trees is irregular" (they then give 1963, 1973, 1984, and 1986 references.) it is likely that virus distribution in rose is also irregular. This explanation appears to be reasonable since virus inoculated plants frquently exhibited some shoots expressing no symptons. It is possible that the virus has not been distributed throught the plant."

Davis had stated the Following: "The second assumption was that the viruses that caused leafroll disease were evenly distributed through infected vines. (Rowhani and Golino, 1995). New technologies and many deteriorating vines later proved both assumptions inaccurate."

I have placed the reference below as it is long and will throw off the line length of the thread.
http://fps.ucdavis.edu/WebSitePDFs/Newsletters&Publications/GrapeNewsletterOct2008.pdf

Here is a link that might be useful: Davis report


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RE: What's the best nursery free of Rose Mosaic virus?

How many posts do you need, Malcolm?


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RE: What's the best nursery free of Rose Mosaic virus?

3 or 4 more!
Yes, the more advanced readers (who of course live in cold climates -- we in the hot climates are the neanderthal readers) can look up Horst's credentials...

Again, quite obviously, the point is being missed (or avoided) entirely. As I said, "I hold Hort's program in highest regard." Nonetheless, the suggestion that 'Nearly Wild' was in some way resistant (notice I say suggestion!) was in error, an error they and everyone else involved recognize as an error, that will remain in print forever as an error.

Now, of course, we have great emphasis in recent posts on the plant's immune system. Again, the writer utterly (and I would emphasize UTTERLY) misunderstands and misinterprets the concept of an immune system in plants, and his musings would be considered ludicrous by those who actually work in that area of research.

Once again, other viruses are being used in unrealistic comparisons, and good research is being grossly misinterpreted. And silly reasons for someone's being unable to find a virus are being suggested. Why not just assume their plants were not infected at all? This is very inconsistent -- a post or two ago, 'Nearly Wild' was just too immune to get infected by the inoculation method the researchers used; NOW they were unable to find it because they didn't have the latest method of indexing and the virus must surely have been unevenly distributed! Which is it???

It is also stated above "I have documented that EISA tests of PNRSV in non rose plants in the field did not find as many infected plants as PCR did. With the first order assumption that all of the plants were exposed to the same general temperature variations, why did they all not have the same virus concentration when measured?" This one should also be rather obvious. As I've said before, no one disagrees that PCR is the more sensitive test, so when titer is low, it would be more accurate, and the specific situation here is said to be "in the field." Well duh! Neither the folks at Davis, nor we, nor anywhere else would collect ELISA test samples from the field unless weather conditions were good for high titer, if our goal was to identify mosaic infection! In the past 30+ years, we've ALL known better than to do that! Just as you wouldn't have a huge breakfast on the way to your doctor for "fasting" blood tests! Of course the tests would be wrong! But you should not then blame the tests as being antiquated or weak; rather, you should fast before you go! DUH! Of course people who don't use ELISA probably didn't know that, but EVERYONE who uses ELISA (with 100% accuracy) have known that since long, long before this discussion began. Obviously, it would be nice to have a method that would work in the field at any time, so research to compare PCR (which, by the way, we've been using for years for rose identification work, but have not used for virus indexing, since other methods have remained cheaper while 100% accurate) with ELISA are quite reasonable and their results quite predictable. No surprises there.

Notice that the statement "Cuttings from an infected plant will be infected - no matter what portion of the plant they were taken from. The disease is systemic: The entire plant is infected, whether visible signs of the disease are present, or not" remains utterly true, and everyone (without exception) who has ever actually worked with rose mosaic would agree with it. To date, there is not a single documented (nor suggested) case of a cutting of a known infected plant turning up as a clean plant later. Not one example. Yet the writer is using a misinterpretation of Davis research to "prove" his point! He demands a refereed paper to back up every claim, but he'll not find one for this one. Every cutting or scion taken from an infected plant (we're talking uniquely genus Rosa and uniquely PNRSV or ApMV here) that has ever been tested has come up infected. Can I promise that in the billions of propagations that were never tested not even one clean plant resulted? Of course not! There are people who win the state lottery. But in every case where the tests were actually done, the infection rate is precisely 100%.

Again, that sort of misinterpretation is called lying. (or lunacy)


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RE: What's the best nursery free of Rose Mosaic virus?

The French reported that: "A total of 89% (59 out of 66) of Anna stems was entirely PNRSV negative when axillary shoots from these stems developed after the decapitation of the floral stem, after the development of cuttings,
or grown in vitro were tested by ELISA. ELISA tests of leaves from these stems were all negative. Since IC-RT-PCR conducted in parallel on all the explants from three (out of seven) of these stems also were negative, we suspect that these stems were virus free, even if they belonged to infected plants, or that the viral titer was very low in the stems."
http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PHYTO.2000.90.5.522

Thus, the French reported in a reviewed published scientific journal that they suspect that they were able to obtain clean plants from cuttings (as determined by the use of ELISA or PCR). They leave the door open that a more sensitive method may find a low amount of infection.
----------------------------------
This is what was reported concerning California Davis ROSE VIRUS experience:
"Oddly enough, one way they eliminate virii is by clonal propagation. Simply put, if you culture enough buds (~100) some small number of them (two or three maybe) will be virus free. The drawback is space, labor and the need to index all the test plants."

Here is a link that might be useful: Report on Davis visit


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RE: A possible rose cleaning procedure to try

In a rose hybridizers thread I made the following statement: "The following grape virus paper suggests that rosarians near/in the California desert MAY be able to naturally "clean" virused roses.

Link: onlinelibrary.wiley.com/doi/10.1111/j.1439-0434.2006.01142.x/abstract
Reply Quote
David Zlesak
Re: Does anyone know about the AARS trials?
October 05, 2011
Thanks for this link Henry!! Wow, it would sure be great to use the strong heat of some of climates to help clean roses of viruses. Even if whole plants are not cleaned up, if we can at least take cuttings or buds from the terminals produced under higher temperature conditions that limit virus replication, it would sure be a great and accessible method for us. Maybe even a hot greenhouse!!

Reply Quote
Kim Rupert
Re: Does anyone know about the AARS trials?
October 05, 2011 Registered: 2 months ago
Posts: 1,454
That's something I often wondered about at Sequoia. At the height of the season, those greenhouses could hit 120 F and they frequently propagated from the plants growing under those conditions. Budding was done infrequently with cuttings making up 99% of everything created. You haven't lived until you've been "pressure cooked" at 120 F with 100% humidity while being dragged through them to "look at THIS one!" Kim"

Here is a link that might be useful: A possible rose cleaning procedure to try


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RE: What's the best nursery free of Rose Mosaic virus?

I have found much of what H has offered here as "documentation" of his ideas to involve a great deal of misinterpretation of the quoted articles, and has little (or nothing) to offer the hobbyist rose growers who reads the forum. None of this answers the original poster's question and only serves to confuse the issue.

What most of us need to know is: do rose viruses spread through the use of cutting tools? Almost certainly not. If it does happen, the rate of infections-per-cut is so low as to be irrelevant. Do rose viruses spread via pollen transfer? Again, almost certainly not. While some research suggests it is possible, clearly it is a rare occurrence (or never happens at all) or we would see every known variety infected with multiple viruses after fifty years (arbitrary number) in commerce. Pollen transmission should be regarded as no concern to hobby rosarians. Do rose viruses transfer through "root grafting" (where one rose's root system fuses with a neighboring plant)? Yes, its possible, but the number of incidents documented are rare. Again, something the average gardener need not worry about.

Viruses in roses spread primarily (read: almost exclusively) by the grafting of one infected cultivar onto an uninfected cultivar. This is how the industry has created the situation we have today; ZERO attention was paid to avoiding grafting uninfected scions to infected root stock, and so many roses we have known and loved for decades (and older) were infected through the carelessness of an industry that thrived on "fast and cheap" production methods. While things are better now in some parts of the industry, (those "discount" roses you buy in bags of sawdust are almost always infected with virus; just because you don't see it doesn't mean its not there) not all roses you buy are guaranteed to be clean, even the newest selections.

You know, I often say to people that fretting and gardening make poor bedfellows. There is no end of phenomenon in horticulture you can read about that can give chronic worriers something new to fret about. Rose viruses, in my opinion, fall into the category of moderate concern: make every effort to acquire "clean" plants, and beyond that, your energy will be best directed to learning how to cultivate happy plants in your circumstances rather than worrying endlessly about the myriad research papers that "suggest" the endless possibilities for virus transmission in numerous genera and how that might affect roses. I don't know about you, but I've got better things to worry about.

What Dr. Manners has said about this subject is all you really need to know. Seriously.


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RE: What's the best nursery free of Rose Mosaic virus?

Paul, I entered this thread by commenting to Kim about what is know about an aphid spread rose virus in California (Thu, Jan 5, 12 at 0:01).
I referenced Davis's report, a Chile report with a color picture of an infected leaf, and on Fri, Jan 6, 12 at 11:43
I stated: "My original post in this thread was directed to Kim. Does Kim have to be concerned about receiving an aphid spread rose spring dwarf infected rose if he accepts a rose with yellow vein symptoms? Please see the link below."

http://www.prevalentviruses.org/subject.cfm?id=58465

(The above link is a report that this virus is widely prevelent in California.)

Here is a link that might be useful: virus distribution report


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RE: What's the best nursery free of Rose Mosaic virus?

I notice that the "Report on Davis Visit" is hearsay, not from a peer-reviewed published paper, and therefore, by Henry's own set of rules, utterly worthless and to be ignored, and indicative that the person posting such a link must be an idiot. I didn't make the rule; I just keep being hit by it, so fair is fair. We are mandated to assume it's entirely a lie.

In all seriousness though, I do have to doubt that the writer clearly understood what was being said there. Now as for apical meristem culture in tissue culture, yes, that has been well-known and documented for many years. We've not used it since heat therapy is easier and more successful (100% successful). But it is certainly used for many plants.

Then, of course, the last-posted link is about an unrelated virus, and so must also be ignored completely in this thread.

And even if the claim about buds is true, my statement is still completely valid -- never once has such a claim been validated in the literature, and in this case, I have to agree (can you believe it?!?!?!?!) with Henry -- without that having been published formally, it must not be accepted as fact.


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RE: What's the best nursery free of Rose Mosaic virus?

The visitor/reporter in his report distinguished between apical meristem culture in tissue culture and bud propagation. Hopefully this link will serve to help explain why I take his report seriously (plus that there existed a published reviewed scientific article that reports doing the same with infected rose cuttings).
http://www.rosehybridizers.org/embryoculture.pdf
--------------------------------------
The statement challenged by me (H.Kuska) was: " To date, there is not a single documented (nor suggested) case of a cutting of a known infected plant turning up as a clean plant later." Please notice that I used the actual quote (in order to be scientifically accurate).

I do not understand why anyone could conclude that the reviewed, published in a science journal, French article is not sufficent to indicate the quoted statement is not accurate.
----------------------------


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RE: What's the best nursery free of Rose Mosaic virus?

Would someone please answer one question? How did the original rootstocks become infected? You guys have stated that the virus is not transmitted by cutting, pollen, proximity to roots etc. Was the first instance a naturally occurring virus in the rootstock? How did it end up on so many pieces of rootstock?


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RE: What's the best nursery free of Rose Mosaic virus?

jackie_o the link that I gave on on Sun, Feb 12, 12 at 21:46
refers to the strains of PNRSV that have been characterized. Hopefully this type of information will someday be useful to trace the evolution of PNRSV as it spread from species to species.

Possibly a good control group will be the Damask rose as it has apparently existed as a cutting propagated rose for a long time. One of the papers that I linked to on: on Sun, Jan 8, 12 at 23:55 is given below. If the long term cutting propagation description is accurate, I would of predicted a very uniform type of virus distribution if natural infection was zero.

Please especially look at the mixed infections.

Here is a link that might be useful: Turkey rose virus situation.


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RE: What's the best nursery free of Rose Mosaic virus?

Here is the reference for suggesting that it may be an appropiate study rose:
"The cultivation of R. damascena in the country was initiated during the 16th century (52)."
"Bulgaria is based on the cultivation of a single genotype of the thirty-petaled R. damascena Mill f.Trigintipetala (47) which has been vegetatively propagated for centuries."
"As mentioned before the same genotype has been reported by several authors as the main genotype used in Turkey and Iran for production of rose oil."
"Crossings between R. damascena and other rose species and especially R. galica have been attempted by rose breeders (51), however these hybrids have never made their way to industrial cultivation because they show changes in the rose oil composition."

Here is a link that might be useful: ROSA DAMASCENA � GENETIC RESOURCES AND CAPACITY BUILDING FOR


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RE: What's the best nursery free of Rose Mosaic virus?

Oh oh -- a report from Turkey -- a hot climate, so obviously it could not possibly be true. But let's assume it is true -- obviously they could not competently test for the presence of any of those viruses -- they are in a hot climate! They use the evil ELISA method! EEEEEK! All of what they say must, by definition, be false.

But let's assume they really do have mosaic and they really do know how to test for it (Henry cannot possibly agree with this, but I can believe it) -- then he says "If the long term cutting propagation description is accurate, I would of predicted a very uniform type of virus distribution if natural infection was zero." But wait! That's totally backward logic. It is only if natural spread is NOT occurring that we could have differences in infections, in a crop grown from cuttings! Natural spread would tend to make the infections uniform. Something they are NOT seeing.

Again, obfuscation and blather.

I'm really annoyed that GardenWeb did not stop this thread at 100 posts. Now we have to put up with more nonsense. Oy!


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RE: What's the best nursery free of Rose Mosaic virus?

Malcolm, have you any theories about where the RMV in the US rose industry originated? Nothing requiring scientific studies nor officially filed documentation, but based upon anecdotal information, educated conjecture or other experience? Of course, I've heard the conjecture it originated with Burbank and his Island of Dr. Moreau experiments budding fruit and roses together. Thanks in advance, Kim


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "I would of predicted a very uniform type of virus distribution if natural infection was zero." But wait! That's totally backward logic. It is only if natural spread is NOT occurring that we could have differences in infections, in a crop grown from cuttings! Natural spread would tend to make the infections uniform. Something they are NOT seeing."
------------------------------------
H.Kuska comment. My suggestion is based on roses having an immune system. i.e. not all roses will get an infection if exposed, especially not all roses will get the listed dual and triple infections. If all roses were cuttings from an ancestor infected plant(s) from some original grafted plant being smuggled in, they will all show the same infection (if the virus was evenly distributed as some here apparently still believe) all cuttings would produce identical virused plants.

Of course the actual behavour will probably be more complex than the first order model. I assume that new cuttings will be selected from the best preforming plants. Thus, there probably is a selection pressure abainst virused roses. Plus there ia reviewed published scientific paper that virused cuttings are harder to root. In virus spread studies, computer programs are used to fit the observed spread pattern to the possible models.

Here is a link that might be useful: rooting of virused roses


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RE: What's the best nursery free of Rose Mosaic virus?

Kim, Yes, the accepted idea of where it came from (accepted by virtually everyone except one) is that it was introduced by failed attempts to graft fruit trees and roses together. This is conjecture, but makes complete sense. And since the disease was noticed only after 'Dr. Huey' became popular as a rootstock (rooted from cuttings rather than seed-grown), that system of growing stocks from cuttings allowed it to spread quickly and thoroughly through the U.S. crop. Of course one person disagrees with this, and will undoubtedly produce countless "valid, reviewed, scientific papers" to "prove" that it's been around for eons before that, but as usual, a careful reading of those papers will demonstrate that he is again misinterpreting or reading into those papers things that were not actually said.

Notice that all discussion here of an "immune system" in roses is more of one person's made-up silliness. Yes, there is RNA interference in plants -- a subject he totally misunderstands and misrepresents, and it has long been known that one viral infection can affect the ability of a second virus to establish in a plant. But the concept of an immune system as suggested here, is not valid.

Of course all of these bizarre arguments continue to be presented to support a false view of the entire situation -- that researchers are not able to determine where infection exists, that the disease is spreading in the field, that it behaves differently in different climates, etc. All of these concepts have been made up by one person and are completely at odds with what the entire rose virus research world knows or believes.

So, we just keep producing clean plants, that remain clean forever. We see no surprises or conflicts at all. We have absolutely no trouble testing for the presence of the disease with 100% accuracy and efficiency. The subject is nicely cut-and-dried. All else here is a lot of hullabaloo for no possible benefit to anyone.


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RE: What's the best nursery free of Rose Mosaic virus?

Well, in answer to the original question by Strawberry, Heirloom says they have imported most of their roses from Europe, where this virus isn't a problem.

Thought that was mentioning. Okay, back to our regularly scheduled program.


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RE: What's the best nursery free of Rose Mosaic virus?

The idea of importing from Europe to avoid virus is a very romantic one...except, by the middle of the last century, European nurserymen were already complaining about the virus infection we had already exported to THEM. Remember that virtually all AARS introductions were made by Armstrong. They supplied the budwood for them and they were well known for their infection of roses which passed through their hands. Remember also, many OGRs were exported to Europe from Roses of Yesterday and Today, who was also well know for their strain of virus.

In Jack Harkness' book, Roses (published in 1977), he addresses the virus issue, speaking about the British irritation over our "sharing" it with them. He further states that one prominent American nurseryman stated he actually thought it added a "decorative effect" to the roses. We had it first and we've shared it freely around the world.

In the 1990s, while visiting Vintage Gardens and being taken on a tour of the Korbel Winery by Philip Robinson then of the nursery and home gardens by Philip and Gregg Lowery, we spoke of our observations about the breadth of obvious symptoms. They stated they had personally observed symptoms on BRITISH RAISED ROSES, not American exports, but roses created in Britain, in Queen Mary's Rose Garden in Regent's Park.

Granted, the use of seedling stocks for production should help prevent spread of infection. But, for any bud wood taken from already infected varieties, using seedlings for roots won't prevent the crop from being infected. Perhaps newer varieties may be prevented from infection, but anything older and already tainted will remain tainted until and unless it is destroyed or "cleaned", including infected Old Garden Roses. Kim


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RE: What's the best nursery free of Rose Mosaic virus?

The following link gives what I found concerning what was known about early observations of rose viruses.

Of course as a scientist I am interested in hearing what the basis(bases) of the statement: "but as usual, a careful reading of those papers will demonstrate that he is again misinterpreting or reading into those papers things that were not actually said." is(are).

Here is a link that might be useful: first observation of rose virus infection


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RE: British rose virus problems

Did we also provide the British with nematode causing rose viruses?
---------------------------
A reviewed scientific publication concerning rose virus in England has stated: "only SLRV was readily seed-transmitted, particularly in R. rugosa.". Please note the appearance of the word "readily".
Also, please note: "Nevertheless, in soil containing viruliferous nematodes, AMV and/or SLRV were transmitted to c. 80% of healthy plants." Please note: "80%".
-----------------------------------
It appears to me that England would be hard pressed to blame the U.S. for what appears to be their most severe rose virus problems, AMV and SLRV.

Here is a link that might be useful: In plantings of up to 7 yr none of the viruses was transmitted through pollen to healthy roses grown in nematode-free soil


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RE: What's the best nursery free of Rose Mosaic virus?

Why is this discussion valuable?

If you are the owner of a small rose distribution company, you are possibly/probably operating on a very low profit margin. Lets say you make every effort not to ship virused roses. Someone buys a rose (at a premium price relative to the big box store price) that sooner or later shows mosaic symptoms. You check the "common" literature such as the 2 articles on the ARS web page and find (for example): " Means of Transmission RM is believed to be non-contagious in the field, except possibly through rare natural root grafts. There is no evidence that it ever spreads naturally in the garden or nursery, or through pollen, seed, or seedlings 2. Extensive tests also have failed to transfer RM mechanically (e.g.,on pruning tools, grafting knives, etc.) 3. The only known means for transmitting the disease is by vegetative propagation."

Also lets say you read in this thread the following: "If you mean rose species, that's probably not a useful question, since the disease is believed (by all but one person) never to be contagious, by any means other than human activity, in the field (by "human activity" I'm including planting them in very close proximity -- inches -- a way one would never grow a rose in a garden)."

----------------------------------------
Lets say you did have a known virused rose planted (2 to 4 feet?) away from your new purchase. Sometime later you observe virus symptoms, call the owner of the company, he/she gives you what you feel is an unsatisfactory answer that his/her roses are not virused. So you post on a rose web page that this dealer should be avoided.
---------------------------------------
It is important for dealers and rose growers both to know that the cited tests are possibly deficient in one or more of the following ways: 1) were not statistically valid, 2) used detection methods not appropriate (sensitive enough) for "real world" spot contact infection detection, 3) were carried out in warm areas in which the known temperature dependent virus immune system may of been able to fight off the attack.
------------------------------
-------------------------------
As an aside, Turkey's climate varies with area. The cited Lakes Area is sheltered from the heat by a mountain range. See the link below. The month with the highest average temperature is July (22 deg C (71.6F)) and the month with the lowest average temperature is January (-0.02 deg C (31.64 F)).
http://balwois.com/balwois/administration/full_paper/ffp-1934.pdf

Here is a link that might be useful: a rose hybridizers discussion with references to dealers


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RE: What's the best nursery free of Rose Mosaic virus?

I for one REALLY appreciate what FSC & DR Manners have done over the years concerning RMV. I saw first hand his work. I lived in Winter Haven for 20+ years and spent MANY hours on campus. I remember when the whole thing got started with a mass planting of a bunch (32 I think) of Double Delights'. You would have to be on campus to understand the work that goes into a project like this. When you see it first hand, you understand what's going on with RMV and how hard it is to clean up.


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RE: What's the best nursery free of Rose Mosaic virus?

"---------------------------------------
It is important for dealers and rose growers both to know that the cited tests are possibly deficient in one or more of the following ways: 1) were not statistically valid, 2) used detection methods not appropriate (sensitive enough) for "real world" spot contact infection detection, 3) were carried out in warm areas in which the known temperature dependent virus immune system may of been able to fight off the attack.
------------------------------ "

Again, and as always, these statements are false and ridiculous. If people were seeing any spread in the field, they might be worth considering. But since there is no evidence for such spread, this discussion continues to be utterly without value. Again, as far as statistics are concerned, in the informal "experiment" of millions upon millions of roses in gardens, worldwide, for there to have never been even one demonstration of spread is pretty good statistics. And even if it were spreading at, say, a rate of 0.000000001%, the probability of it happening in YOUR garden to YOUR rose is likely far less than the chance of you winning the lottery while being struck by lightning. It's really, truly, not worthy of consideration.

As for insensitive detection methods -- as I've stated many times, only one person in all the world would argue that we have ever failed, even once, to detect PNRSV and ApMV when they have been present. There is no inadequacy at all to the indexing methods being used -- they are 100% effective. NO ONE else disagrees with that. The claim that sometimes ELISA can't detect a virus in the field is misleading -- no one who knows what they're doing would consider trying ELISA under inappropriate conditions. The research showing that PCR was more sensitive was a very valid test to show that it could detect the virus when conditions were inappropriate for ELISA -- good information to know -- but note that those same researchers would NEVER routinely use ELISA as a means of diagnosis under those conditions! We're really not idiots. Since there is precisely zero evidence that any researcher using the "standard" methods of indexing has EVER failed to get the diagnosis right, even ONCE, in all of rose research history, again indicates that the continuation of this discussion is ridiculous.

And the concept of warm climates affecting an "immune system" is unique to this one writer, completely lacking in any evidence for it. It's preposterous. He keeps proposing it over and over and over, as if it will become true at some point just because he says so. It is not true. He's mistaken. Notice that NO cold-climate researcher is claiming to see any spread at all, by any means, nor is any cold-climate researcher seeing/reporting ANYTHING different from the hot-climate researchers. It's entirely a made-up story believed by one very persistent person!

And as always, all of his peer-reviewed references, while excellent papers, really don't claim what he says they are claiming, and they do not support any of these wild claims in the least.


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "If people were seeing any spread in the field, they might be worth considering. But since there is no evidence for such spread, this discussion continues to be utterly without value."
--------------------------------------
H.Kuska comment. Professor Horst (Cornell University, Plant Pathology) wrote: "PNRSV is pollen-transmitted in fruit trees. Pollen transmission is suspected to occur in roses also, since spread in the field is slow."
Horst, R., K., book "Compendium of Rose Diseases", published by The American Phytopathological Society, St. Paul, Minnesota. pages. 26-27, (1983).
A Google Book search with the search term "since spread in the field is slow" suggests that the information is also in the 2007 edition. Can anyone verify?

=====================================
The following appears in one of the 2 ARS web pages concerning rose mosaic viruses (linked to at the bottom of this post):
"There have been some lively debates over exactly how mosaic spreads in roses. Aphids,thrips,pruning shears,contaminated soil,root contact and pollen have all been suggested (Cochran,1988;Davidson,1988;Horst,1983,Manners,1988)."

AND

"It seems likely that the unsubstantiated reports of natural or mechanical spread of the disease,which appear from time to time,are due to misinterpreted observations either the plants which appear to have contracted mosaic were infected all along and have just begun showing symptoms,or perhaps symptoms which are interpreted as being those of mosaic are in fact something else."
----------------------
H.Kuska comment. Since a reference to: "Davidson H 1988. Letter to the editor. The American Rose Magazine.29(15):16." appears in the same ARS article, I am presenting a link where Davidson's letter is discussed.
The link below which references Davidson's letter (he is a northern California rose hybridizer (with All American sRoses to his credit)).
-------------------------------------
http://www.rosebreeders.org/forum/read.php?2,1467
==================================
Back to the ARS Rose Mosaic paper (linked to at the bottom of this post). The author states: "Only carefully defined and controlled test conditions,and indexing or ELISA testing for the presence of virus before and after the experiment,can give useful information on contagion. Other researchers have found no evidence from such properly controlled experiments that rose mosaic spreads by any means other than grafting or budding (L. C. Cochran,Oregon State University;Charlene Harwood,Bear Creek Nurseries;George Nyland,University of California; ). Our results completely support that premise:no contagion occurred from pruning shears,insects,or any other means."
-------------------------------
H. Kuska comment: Please notice that all of these references are personal communications. Have they later been published in reviewed scientific journals? Also, this is what I found about something published by the THE PROCEEDINGS OF THE FLORIDA STATE HORTICULTURAL SOCIETY.
"III. MANUSCRIPT REVIEW AND PUBLICATION COSTS
A. Review. Papers presented for publication in the Proceedings are generally published with some editorial changes. However, editors may request revisions if manuscripts are verbose, unclear, not in the proper style, or contain extraneous or improperly documented statements. The Society reserves the right to reject papers or to publish them as abstracts only as determined by the Section Associate Editor with concurrence of the Editor. In a case where the Editor does not concur with the Associate Editor, he shall notify the Associate Editor of his reason in writing."

http://www.fshs.org/PDF/FSHS_Author_Instructions.pdf

Was this the policy when this paper was submitted? i.e. Was it submitted to outside review by your peers?

Here is a link that might be useful: ARS Rose Mosaic paper


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Who chooses which roses to treat?

Dear Dr. Manners,
First of all let me say thank you for doing this work. The plants I have gotten may have come from your program and they are well worth many times the price I have paid for them. There is no doubt that these roses are getting to be stronger plants with each passing year compared to infected ones I started with in the early 80s which have declined and mostly now replaced.

Most of my questions have been answered but one. How do you choose which roses to treat and can this be done by request. I have a very pretty sport of a famous 70's AARS winner but sadly it came from a virused plant ( still going strong but is virused just the same ). I imagine it is time consuming and expensive to do the work so I wonder how you choose which roses to work with.

Another question is
If I want to try and save my sport should I try to have it budded onto stronger roots. Right now it is just one own root plant doing well.


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RE: What's the best nursery free of Rose Mosaic virus?

Notice in the last HK post that all of the citations on slow spread in the field are from the 1980s. It's been nearly 30 years, folks! In all that time, any such "suspicions" have been laid to rest -- still NOT ONE INCIDENCE of spread in the field has EVER been demonstrated. How many times must one say this? Notice that even Mr. Peer-Review himself has not cited a single peer-reviewed paper that has demonstrated such spread. NOT ONE! And that's because there aren't any.

Remember, if peer review is needed for something to be true, then nothing HK has said on this thread (nor any other, ever) has been true, since NONE of his writing on rose mosaic nor any other aspect of roses has ever been peer-reviewed. I don't really believe that -- while peer review certainly has its place, it is NOT necessary for something to be believable or true. But apparently those are the rules here! And of course, the assumption above is that all of those great and respected rose mosaic researchers write one thing in their peer-reviewed papers, but then they tell blatant lies when they give personal communications! How amazingly ridiculous is that??? How low can one stoop? How naive can one be?

Kitty, we have mostly treated plants sent to us by nurseries. There is a fee involved, which doesn't quite cover the real cost of the process (I have never received a penny of it myself -- I do the work strictly on a volunteer basis). We've also tried to emphasize the older varieties that UC Davis has not had an interest in. Email me if you want to discuss this further.


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "Notice in the last HK post that all of the citations on slow spread in the field are from the 1980s. It's been nearly 30 years, folks! In all that time, any such "suspicions" have been laid to rest -- still NOT ONE INCIDENCE of spread in the field has EVER been demonstrated."
-------------------------------------
H.Kuska comment. The Horst's quotation appeared in 1983 and appanently in 2007. What 2007 is telling me is that the suspicions have not been laid to rest. To use your own words ""Only carefully defined and controlled test conditions,and indexing or ELISA testing for the presence of virus before and after the experiment,can give useful information on contagion."
I have attempted to document my statements that ELISA has been shown to have sensitivity limitations. I have attempted to documented my statements concerning present knowledge of temperature dependent immune system behavour. I have pointed out that scientifically valid experiments have to take into consideration sample size. One of the e-mails that I have received stated that he/she had contacted one of the top rose virus researchers and asked about proof of spread. The answer came back along the lines: there is no proof of lack of spread.
--------------------------
Observed spread has been reported. Until the properaly designed experiments are done, on my web page

http://home.roadrunner.com/~kuska/info_about_virus.htm

I state:

"Thus, until spread research is done in northern climates, I recommend that basic precautions be utilized to prevent/minimize the possibility of above ground spread."

Thus, I agree with the most recent California Davis Extension Service recommendation (which has survived at least one revision) to: "In the meantime, you need to remember that viruses can be transmitted by pruning and cutting shears. Virus-infected plants should be pruned last and/or have their flowers harvested last. To be extra cautious, wipe your cutting shears with alcohol (rubbing alcohol is good) or a 10 percent bleach solution between plants."
---------------------------------
I feel that the ARS membership would be better served to have this paper as a source of information concerning viruses. Apparently the California Extension Service, Davis feels that way for the citizens of California.
----------------------------------
As I cite on my web page this is what their function is: ("Extension is the other part of our name, Extension, indicates what we do. We extend research-based information from the University of California, other universities, and federal agencies, as well as our own local applied research.").

Here is a link that might be useful: most recent California Davis Extension Service recommendation


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RE: virus spread in roses What's the best nursery free of Rose Mo

Please notice that the extension article cited earlier did not say RMV, it said rose viruses. I feel that attempts to limit the discussion to one or a few viruses (which even cannot be justified by the literature) is missing my point that rose gardeners should be informed that a rose virus may appear in their rose beds that is not there because of the fault of the seller.
A quote from the link below: "Purchasing virus indexed (VID) stock GREATLY enhances the likelihood that you will get disease-free roses. It is not, however, an absolute guarantee. I'm not the only one to have purchased a VID selection of a certain hard-to-find rose, only to see those unmistakable signs of virus appear as the rose matured. The article Diane linked above encourages customers to quiz vendors about the VID status of their stock. That's certainly a fine thing to do. Just be aware, though, that the answers and/or evasions you're likely to elicit, even from some highly reputable vendors, may serve only to increase your frustration. Most small rose businesses do their best to acquire healthy stock, but few (if any) of them have the resources to have those highly technical & fairly costly lab tests performed on each variety they sell."
http://forums2.gardenweb.com/forums/load/roses/msg022235431402.html
--------------------------------
Back to a discussion of the following statement: "Notice in the last HK post that all of the citations on slow spread in the field are from the 1980s. It's been nearly 30 years, folks! In all that time, any such "suspicions" have been laid to rest -- still NOT ONE INCIDENCE of spread in the field has EVER been demonstrated."
Posted by henry_kuska z5 OH (kuska@neo.rr.com) on Fri, Feb 5, 10 at 18:05

If one is interested in old garden roses, then one should be aware that another rose virus (rose leaf curl) may be a problem.
"In the United States, the infectious agent of rose leaf curl occurs in many �antique" roses in community rose gardens. The disease is widely distributed in the United States, but when it is seen in hybrid tea roses in public gardens, "antique" roses are usually nearby."

http://web.aces.uiuc.edu/vista/pdf_pubs/632.pdf

Is it still considered a problem? The following is from a March 2009 University of California paper:

"Infected rose plants. Slow natural spread."

http://www.ipm.ucdavis.edu/PMG/r280112611.html
---------------------------------------------------
Please notice the statement: "The disease is WIDELY DISTRIBUTED in the United States," and compare that to the earlier statement: ""As used by gardeners," rose mosaic in the USA is well more than 99% PNRSV, substantially less than 1% ApMV, and so exceedingly much less than 1% all other viruses combined as to be completely ignorable and irrelevant."
-----------------------------
Please notice that the extension article cited earlier did not say RMV, it said rose viruses. I feel that attempts to limit the discussion to one or a few viruses (which even cannot be justified by the literature) is missing my point that rose gardeners should be informed that a rose virus may appear in their rose beds that is not there because of the fault of the seller. As indicated by the above this appears to be particularly important for those interested in antique roses. ("The disease is widely distributed in the United States, but when it is seen in hybrid tea roses in public gardens, "antique" roses are usually nearby.")


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RE: What's the best nursery free of Rose Mosaic virus?

Malcolm, can I offer you a martini??!

I would like to draw attention to a statement Kim made in this discussion, regarding the importation of roses from the UK and the infection status of those plant materials.

What Kim said is quite accurate: many of the OGRs that were in commerce in the UK from the late 1960s onward had been imported to the UK from the US, from sources that are well known to have been the primary source of virus infected roses in the US. (in that era of commercial rose production) Any US nurseries that claim their roses are virus free just because they have imported plant material from non-US sources, is spouting misleading marketing rhetoric and nothing more. If you choose to believe that kind of statement, that is your choice, but in no way does it represent some kind of infallibility or superiority of stock offered by that nursery. Caveat emptor, and all that....


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RE: What's the best nursery free of Rose Mosaic virus?

Well, as I said before, it's truly hopeless. Just hoping thinking readers will realize where the lunacy lies, here. Interestingly, when the public asks Davis for advice concerning rose mosaic, they often refer them to what I've written (personal communication from them -- Yes I know, all "real" scientists lie every time they give a personal communication). I've also had many discussions with the folks at Davis, and yes, they and we agree utterly, absolutely, on every aspect of rose mosaic.

Whatever hooey is referred to above, no, no spread in cold climates has ever been demonstrated, nor is there any reason at all to think that it might be spreading.

Davis deals with many viruses on many crops. True, some are equipment-spread. The viruses causing rose mosaic are not among those.

Since virtually all of the "virus" that American rose growers are interested in is rose mosaic or rose rosette, yes, there is indeed good reason to limit this discussion to mosaic, since that was the original purpose of the thread.

As always, the goal here seems never to be truly educated; rather it is blather and obfuscation, over and over and over and over and over again. It never ends. Yet nothing useful ever comes of it. It just makes people annoyed (and they should be annoyed!). What a waste of time.


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RE: What's the best nursery free of Rose Mosaic virus?

Malcolm -- It's been said that the only good thing about beating one's head against a wall is that it feels so good when one stops.

We can do nothing to guarantee world peace, or save the planet from the loonies who are convinced that humanity is duty-bound to despoil the environment UTTERLY before the prophesied arrival of the rapturous end of days. Ergo, why be dumbfounded that some choose to obsess over RMV and ignore the science that you have so patiently & so astutely attempted to convey?

At your request, here's an altogether appropriate coda to this impossible exchange . . .

Here is a link that might be useful: This Song's For You


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RE: What's the best nursery free of Rose Mosaic virus?

Oh, I was so waiting for someone to post that music! Thanks jaxondel! Love the comment about heads and walls, too.


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RE: What's the best nursery free of Rose Mosaic virus?

One of the cited scientists in the ARS paper is "Charlene Harwood,Bear Creek Nurseries."
-------------------------------------
She was the Ph.D that was in charge of the J&P virus cleaning program.

The reader may find this of interest:
"I have an acquaintance here in Southern California. She is of the mentality, "absence of light black and Resurrection White", no gray areas in anything. She was, for many years, a rabid exhibitor, to the point of having multiple florist freezers in her home to hold her blooms for shows. She had dozens of portable gazebos to move around her garden to protect the buds as they formed. She was determined to grow uninfected varieties only as symptoms would disqualify her entries. J&P had begun their VI program and reserved the VI plants for specific states as the laws in those states had changed, making it illegal to supply virused stock across their state lines. She badgered J&P for their VI stock, then had it tested. Surprise! The results were that the VI stock was infected with the specific viruses tested for. She loosed her wrath on J&P and the PhD who ran the VI program. They replaced the plants, which, in turn, tested positive. When she contacted J&P again, she was told the program had been dismantled and the woman PhD in charge, reassigned as they found, even when grown in "sealed greenhouses with no possibility of spread, the viruses spontaneously regenerated". They refused to replace the stock a second time."

The above was posted on Fri, Nov 5, 2010. Please read the following link to put in context:
http://www.rosehybridizers.org/forum/message.php?topid=31712#31864

Please note: "they found, even when grown in "sealed greenhouses with no possibility of spread, the viruses spontaneously regenerated"

Here is a link that might be useful: link for above


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RE: What's the best nursery free of Rose Mosaic virus?

Thank you, Paul. That is a point I have endeavored to make clear for a very long time. Should anyone wish to know WHAT roses we could be talking about, please refer to this archive of availability on HMF. And remember, this only represents less than HALF of the catalogs, hence potential varieties infected and distributed by this source. Anyone obtaining material from this source for sale or production, or providing propagating material from any plants obtained from them, spread the infection further. In those years, it seemingly didn't matter. It's only been less than half the time the issue was identified and known that anything could be done about it. In many cases, they were the ONLY source for the variety. In many cases, only plants originating from them have been the only plants to be found.

In all the years I sought Fiesta, the striped sport of The Queen Alexandra Rose, I have only encountered three plants. One was grown by a fellow Huntington volunteer, which she purchased from Roses of Yesterday and Today. The second was grown by a gentleman I met while working a Friends of The Huntington Plant Sale, which he purchased from Roses of Yesterday and Today. The final plant is the one Vintage grew, which per page 91 of their Big Catalog (1996), they obtained from Roses of Yesterday and Today. Kim

Here is a link that might be useful: Historic Archive


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RE: What's the best nursery free of Rose Mosaic virus?

Well that's an interesting (but completely wrong) take on the history at J&P. Unlike "personal communications" from scientists, which tend to be true, what one hears from a corporation trying to save money often varies considerably from the truth. 'Nuff said...

I do know that J&P's heat therapy system was quite non-standard, and I used to wonder how they could get clean plants out of it -- obviously they couldn't -- no surprises there.

We'll probably never know for sure what all happened at J&P in those days. What we DO know is that nothing of the sort every happened anywhere else, so what one hears by hearsay is very likely not true.

As anyone who knows anything at all about virus will tell you, viruses do not "spontaneously regenerate," ever. The concept is ludicrous.

Jax, I did enjoy the music! Thanks!


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Enough!

Henry, stop it. Attempts have been made to figure out how to find material which may have potential for not being infected with RMV. All of the stuff you have drowned us with, you have previously regurgitated here and elsewhere. Your efforts are not intended to answer the original question, nor to assist in finding solutions.

Your quotes, including the one above, have been previously been hashed and rehashed and serve no beneficial purpose. Kim


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RE: What's the best nursery free of Rose Mosaic virus?

"the viruses spontaneously regenerated"

Baloney. Absolute baloney. I have had sufficient personal interaction with J&P representatives to know that no statements on their so-called "clean up" program can be believed.


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RE: What's the best nursery free of Rose Mosaic virus?

Threads now run to 150 messages.


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RE: What's the best nursery free of Rose Mosaic virus?

Thanks so much for the input on the comment by Heirloom that its roses are virus free. I'd thought it was a rather bold statement and have been curious about it.

Kim, I looked up that quote in the Jack Harkness book and thought I'd write it out as it's quite interesting. One thing that finally makes sense to me now from reading it is why any cuttings taken from the plant will have RMV. This has been very interesting reading, thanks. I have just blinked hard as I scrolled down.

from "Roses" by Jack Harkness

The 1950s marked the greatest dominance which American rose breeders had ever known; I have tried to pick out the most significant Hybrid Teas of the decade, and about half of them come from the United States. Perhaps I should add here that the American growers gave us free with their roses the unwanted gift of a virus called rose mosaic, which they knew perfectly well inhabited pretty well their entire stocks. Their view was that it appeared to have no detrimental effects on the roses, and was therefore not worth worrying about; indeed some went so far as to advance the possibility that might be beneficial. This mosaic may be recognized as yellow tracery upon the leaves, and it always adopts a symmetrical pattern, and may thereby be identified. It is most likely to be seen in very hot weather; although if it cannot be seen, one should not conclude that it is absent. It lies within, latent, ready to do its stuff when conditions invite, just like countless other organisms which inhabit living bodies, including yours and mine. It lives in the sap of the plant, and may be transmitted by intrusions of the sap, which occur mainly through the bites of insects or the tools of the rose growers. The great means of transference in America was through the roots they grew their roses on. In Europe, these were supplied by rootstocks grown from seed, through which mosaic is rarely passed. But in America, they grew them from cuttings, and once the stocks from which cuttings were taken were infected, then every rose granted on them was infected too. After much complaint from Europe, the Americans began some cleaning up, but I don't know that they have much heart in it. Well, when you consider that every plant of 'Queen Elizabeth' most probably has rose mosaic, you can understand their skepticism. p. 102-103

and from comments about 'Queen Elizabeth' p. 124, just to make sense of the last sentence above, "Looking back through the years of my life as a rose grower, I think this is the best rose raised during that time. Its vigour ensures easy growth and good performance..."


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RE: What's the best nursery free of Rose Mosaic virus?

Thank you Gean! Sorry for mis-remembering it a bit, but I did remember it was there. Great book, isn't it? Kim


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RE: Jack Harkness book

Kim, it is a book I am very glad to own and have you to thank for recommending it to me! :)


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RE: What's the best nursery free of Rose Mosaic virus?

The following was stated: "Your quotes, including the one above, have been previously been hashed and rehashed and serve no beneficial purpose. Kim"
-----------------------------------
H.Kuska comment. Kim please provide a link(s) for where my last quote has been hashed and rehashed. Also, was that quote one that you made? I assume that that thread is still open. Are you going to retract it?
Are you also going to retract your part of the following:
"Posted by Jim Sproul (zone 9) [email] on Wed, Nov 10, 2010
Hi Henry,

Asking questions and seeking the answers are marks of a good scientist. I think that you have done an excellent job scouring the literature to find information to help answer the questions that you pose. I agree with you that it doesn't all add up yet, that there are still unanswered questions, that the evidence is conflicting.

My purpose in this discussion is to encourage the enjoyment of rose breeding. I wouldn't want new rose breeders to worry too much about RMV type viruses being an important factor in their new hobby. They haven't been an important obstacle for me over the 20 years that I have been breeding roses (with the exception of my mentioning the instance where some of my seedlings were grafted onto virus infected rootstock by one of the commercial growers).

I understand that there may be different experiences among northern rose breeders, but even then, I suspect that the absolute effect of RMV type viruses on a breeding program would be small. You are right that the question has not been answered. It would be interesting to conduct controlled experiments to get a better handle on the degree to which the rose immune system is challenged by cooler climates, and whether there is a greater impact there with respect to RMV type viruses.

Jim Sproul

----------------------------------------------------------
Re: Yellow Queen Elizabeth
Posted by Kim Rupert [email] on Wed, Nov 10, 2010
Yes, I join Jim in thanking you for sharing such a great breadth of information and research, Henry. While many questions do remain unsatisfied, many others now make a whole lot more sense. Thank you! "
===============================================
The following was stated: "As anyone who knows anything at all about virus will tell you, viruses do not "spontaneously regenerate," ever. The concept is ludicrous."
-----------------------------------
H.Kuska comment: Please notice the use of the word "EVER" and compare it to the following reviewed published scientific statement: "Temperature sensitive mutants that have the same mutation in the same gene will for example not be able to complement each other. It is important to distinguish complementation reactivation where a higher dose of inactivated mutants will be reactivated and infect a cell because these inactivated viruses cooperate in a poorly understood process. This reactivation probably involves both a complementation step that allows defective viruses to replicate and a recombination step resulting in new genotypes and sometimes regeneration of the wild type."
http://science.jrank.org/pages/7190/Viral-Genetics.html
---------------------------------
H. Kuska comment: I do not think that actual regeneration was what J&P is referring to, I feel that it was what I gave a quote (and link for) for on Fri, Jan 13, 12 at 11:58. "that virus levels may be temporarily reduced below the level of detection resulting in a negative virus test, but after some time (several weeks), as the plant matures, virus levels return to normal allowing a positive test result.
==================================
Concerning the following quote: "What we DO know is that nothing of the sort every happened anywhere else, so what one hears by hearsay is very likely not true."
H.Kuska comment. I have given the links to 2 statements stating that they were told by California, Davis that it happened.
"The following statement was made in 1988: "Well, Malcolm, then you had better speak with the folks at Davis!
Because some years ago they reported to the group at the inaugural meeting of a California rose plant grower's association meeting at Davis that virus DID in fact spontaneously reappear. AND said plants were in an screened, isolated green house, to boot!
I know what I heard that day at Davis, and other people in that audience heard it, too."
http://groups.google.com/group/rec.gardens.roses/msg/61458eaadecee942?dmode=source
AND
"The following link contains the following 2005 statement: " I've had the opportunity to attend a couple of the GRC meetings, including one where various RMV's were discussed. I think that the reference to "supposedly clean blocks" was made in a discussion of varieties that had been heat treated. They were surprised to see virus infected plants showing up again after they had been indexed at Davis."
http://www.rosehybridizers.org/forum/message.php?topid=5948#6012


Here is a link that might be useful: My link on return of virus information


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RE: What's the best nursery free of Rose Mosaic virus?

Same old gossip so I'll repeat my mantra of the last 12 years: Never seen a case of RMV in any OGR in any garden or collection in the UK. Never heard a report of any such sighting - even from dear American rosarian visitors over many decades. One would assume that had virused budwood from California been imported to the UK, propagated here and distributed widely across the UK and Europe, Australia, South Africa, New Zealand, etc through OGR nurseries, then those plants - even down to today's descendants - would be virused, and even the dim-witted foreigners might have noticed and reported same.

Apparently the Lester/Tillotson virus is so stealthy that it lies completely hidden until it hears an American accent and knows it has come home - an early form of bio-terrorism?

We have enough pathogens of our own, and any responsible nurseryman would follow Harkness in roguing-out and destroying weak or diseased material before it got to market. Harkness's remarks were specific to the American-raised HT's of the 1950's. Most of which I am delighted to have seen the back of:)

I would be glad to see *factual* information - not the usual gossip from the same old sources (who, as far as I know, have never visited English rose gardens themselves) - on what varieties of OGR's are said to have taken this route. To say 'all of them' is patently ridiculous. By far the greatest proportion of OGR's imported into the US from Europe (and that obviously includes almost all varieties) did not originate from Californian stock.

On a related matter of interest to me - some years ago the collection with which I am associated sent budwood (gratis) of a great many OGR varieties to the group responsible for the start-up of the San Jose Heritage Rose Garden. The propagation from that material was carried out by Tom L, who has since - and frequently - been lambasted by rosarians on this forum for selling virused material. Does this mean that all the OGR's supplied to the Heritage are virused? And all those distributed from there to the majority of well-known OGR nurseries/collections in the US? And which of them were already virused from their earlier trans-Atlantic voyages? And why are those varieties clean elsewhere in the World?

*Just the facts* please, gentlemen! The rose world is too full of under-researched, hurtful and damaging 'apocrypha'.

Best wishes
Jon


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RE: What's the best nursery free of Rose Mosaic virus?

Jon, I've not yet found a rose that went through the RYT nursery that was not infected with that same characteristic strain of PNRSV. I don't know when they first acquired the virus -- it's entirely possible that they were in business for quite a while before that happened. So perhaps some of their earlier releases were clean.

In thinking about mosaic in Europe -- I've seen quite a lot of it at Kew, but as I recall, that was always on modern HT/G/F classes of roses. I can't recall ever seeing it on an OGR. I do believe that most of Europe's own roses remain clean.

And in some defense of Heirloom, in addition to importing their stock, it was my understanding (from direct correspondence with John Clements) that he was having the entire collection indexed by Washington State's ELISA lab. I don't know that that got completed before John's passing, but he had the concept anyway.

And HK again brings out the old "H.Kuska comment. I have given the links to 2 statements stating that they were told by California, Davis that it happened.
"The following statement was made in 1988: "Well, Malcolm, then you had better speak with the folks at Davis!
Because some years ago they reported to the group at the inaugural meeting of a California rose plant grower's association meeting at Davis that virus DID in fact spontaneously reappear. AND said plants were in an screened, isolated green house, to boot!
I know what I heard that day at Davis, and other people in that audience heard it, too."
http://groups.google.com/group/rec.gardens.roses/msg/61458eaadecee942?dmode=source
AND
"The following link contains the following 2005 statement: " I've had the opportunity to attend a couple of the GRC meetings, including one where various RMV's were discussed. I think that the reference to "supposedly clean blocks" was made in a discussion of varieties that had been heat treated. They were surprised to see virus infected plants showing up again after they had been indexed at Davis."
http://www.rosehybridizers.org/forum/message.php?topid=5948#6012 "

So I must again point out that after that, I talked with the head of FPMS Davis as well as their main field manager, both of whom were unfamiliar with those statements, but assured me that they most definitely were NOT true, that they had never seen any such thing, and someone (perhaps their own spokesman at some meeting) had their "facts" wrong. Notice again, that was 24 years ago. One would think that if those "facts" were correct, someone would have noticed. But what we have here is mistaken hearsay from a meeting, not, as HK would normally demand, a peer-reviewed published paper. It is not true, FPMS Davis themselves say it is not true, and there is no documented record of it. As for the 2005 comment "I think that the reference to "supposedly clean blocks" -- how iffy and hearsay can you get? Again, FPMS themselves say is not a true statement.


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RE: What's the best nursery free of Rose Mosaic virus?

"ann peck
Re: Mosaic virus or what?
July 17, 2011
A problem with Elisa is that it's visual and it can only identify viruses that are in plants with a high titer of virus.

The coming thing in plant pathology is virus extraction and then replication and the resulting material is sequenced and compared with known primers. (The work done to isolate the Rose Rosette virus give detailed descriptions of the procedures; they're in Alma Lacey's M.S. work.

This sort of approach is far more definitive that Elisa tests; it's also how Rose Spring Dwarf was isolated and described.

I don't know who's doing comparable virus work in Europe. Kaminska and his collegues in eastern Europe have done similar work on phytoplasmas in roses (in Glass House roses in Europe) as well as in many other plants."

http://www.rosebreeders.org/forum/read.php?2,37093,37093#msg-37093
---------------------------------------
Also please read carefully the statement that I posted on Wed, Feb 15, 12 at 0:38 by Dr. Zlesak, one of the scientists that is doing Rose Virus research.
" "This is a very interesting line of thought. Elisa isn't always that accurate depending on ones threshold for color (background color can vary depending on things inherently in the rose tissue which can be partly cultivar dependant) and how concentrated the virus is."
---------------------------------------
I would like to blacken "HOW CONCENTRATED THE VIRUS IS".
==========================================
Help-ME-Find has a rose virus link to a New Mexico State report that is no longer active. I recommend that it be replaced with the California Extension Service report or possibly it and Dr. Zlesak's concluding paragraph:

"In the meantime I think, if possible, we should remove plants with obvious signs of infection and try to use good sanitation and pruning practices."

http://www.rosebreeders.org/forum/read.php?2,14137
========================================


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RE: What's the best nursery free of Rose Mosaic virus?

"Threads now run to 150 messages."

Which means we are close to done with this, thankfully.


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RE: What's the best nursery free of Rose Mosaic virus?

The following link is from Paul Barden's web page.

Here is a link that might be useful: link referred to above


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RE: What's the best nursery free of Rose Mosaic virus?

In reference to Tom L -- I seem to remember that he had plants budded by a third party vendor, and discovered to his dismay that all the rootstock they used was diseased. It was a bad year for him. In that case, healthy budwood became contaminated by the rootstock. Could that have been the budwood you are describing, Jon? I had no idea that it was such valuable material. This would have been sometime in the early 1990s when I was still fairly new to old roses. Perhaps someone else who was active then could remember the details more clearly. It was much discussed here on this forum before mention of Mr L's name was banned on GW and he became known as the Unmentionable Rose Grower.


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RE: What's the best nursery free of Rose Mosaic virus?

Since Harkness (and now Jon) both say that virused roses started showing up in Europe in the 1950's, isn't that when the bulk of the American production was being budded onto selected multiflora? Not seedling multiflora, but carefully developed clones. Somewhere in the old ARS Annuals upstairs there are articles on the best rootstock, and those are always the top rated ones.


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RE: What's the best nursery free of Rose Mosaic virus?

Again, ELISA, when properly done, is 100% effective, and has never once, in the 30-ish years we've used it, failed to give an accurate analysis. This is considering the following:

1. We always enclose "blind" samples of known infected and known uninfected tissue -- blind to the lab -- and unless the results come back with them correctly identifying all of those, we would not believe their results on our unknowns. That assures that virus titer is in a usable range on the day the test was done. In actual fact, in all those years, they (WSU Prosser's ELISA lab) have NEVER gotten one wrong, even once. Pretty good record.

2. Once that's done and a rose is "certified" clean (notice that ELISA is just one of the tripod of tests we run -- they're also tested with 'Mme. Butterfly' and 'Shirofugen' cherry -- all 3 must come out unambiguously clean) -- no rose once certified in that way has EVER later been found to have rose mosaic. Not one. Not ever. Not even in cold climates where all the intelligent people live. On rare occasions, the lab has said a test was somewhat ambiguous, and in those cases, we ignored all of the results from that run, and re-ran them later.

3. While we use the three tests for redundancy, we've never seen a case in which one test came out positive while the others came out negative -- in 100% of the roses I've ever tested, all three methods have agreed on their result.

So obviously, the point of this long, drawn-out discussion with all kinds of complaints, is moot -- there is no problem here. We have no problem at all identifying where the disease is. No evidence to the contrary has been presented here.

I would like to say that you can't argue with absolute 100% success, but obviously, there is one person who is determined to argue continuously with absolute 100% success! So yes, I'm just working our way toward the 150 posts mark, and hoping to keep us focused on the real issues, rather than being constantly drawn into perfectly silly little side arguments that are in and of themselves without merit.


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RE: What's the best nursery free of Rose Mosaic virus?

If you have decided to disinfect your pruners, the following link from Washington State University may help get you started.

"To disinfect your tools or not - what's the bottom line? To make an informed decision, you need to know your pathogen and its life history, and use common sense:

♦ if it's a virus or viroid, disinfect your tools."

.......

♦ if you are pruning irreplaceable plants, disinfect your tools."

Here is a link that might be useful: pruning plants fact sheet


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RE: What's the best nursery free of Rose Mosaic virus?

"To disinfect your tools or not - what's the bottom line? To make an informed decision, you need to know your pathogen and its life history, and use common sense:

♦ if it's a virus or viroid, disinfect your tools."

At no point in the Chalker-Scott article cited (pruning plants fact sheet) does the author speak about rose virus/RMV/PNRSV. And yet we know that some viruses have been demonstrated to be transmissible by cutting tools, while others are not (or the infection rate is extremely low/negligible) So why cite an article that isn't speaking to the issue of RMV transmission? It isn't relevant.


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RE: What's the best nursery free of Rose Mosaic virus?

Jon -- Re. the Heritage.
I actually asked that question. The answer was that the roses planted in the Heritage were NOT grown with Mr. L's commercial stock, and they were planted on VI Huey rootstock.

Jeri -- Who gets curious, sometimes, and asks.


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RE: What's the best nursery free of Rose Mosaic virus?

Thanks, Jeri - that's good to know.

Best wishes,
Jon


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RE: What's the best nursery free of Rose Mosaic virus?

Again there is not the vaguest evidence for tool-spread of rose mosaic. PNRSV and ApMV are very fragile viruses and not at all easy to spread. Even when grafted, it takes about 3 days for the virus to begin to move from the infected side of the new graft to the uninfected side -- after mitoses have begun and a callus bridge has begun to form. Until then, even intimate tissue-to-tissue contact does not result in spread.


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RE: What's the best nursery free of Rose Mosaic virus?

Thanks Malcolm. 150 you say? Kim


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