Hi KM. Unless the RdV is advertised as VI, don't make any assumptions about its not being infected. VI is not a guaranty there is no infection. All it means is the particular cultivar was treated, tested and no evidence of infection was found. Anyone offering a VI plant of any rose will most often advertise it as such. Kim

To expand -- at one time, RdV was ONLY available in virused form. If a "clean" clone has been developed, I've not heard of it.

Remember that Virus Indexed does NOT mean that all clones from the treated plants are guaranteed free of virus -- tho they may be, and HOPEFULLY are.

Jeri

"VI" does not mean "guranteed virus free". The wording on the Foundation Plant Services site plainly states that. There is no guaranty there isn't infection too low to be detected nor that there will never be a future infection. ALL it means is the plant from which the material has been collected has been treated, tested and not shown evidence of infection. FWIW. Kim

It was our program that cleaned up Reine des Violettes. It has tested clean multiple times, over many years. So while no one can utterly guarantee freedom from virus diseases, I think it safe to say that that strain of RdV is as likely clean as is any rose anywhere.

I think there may be some misunderstanding here -- the concept of a titre "too low to be detected" remaining in a plant. That might happen in some tissues, in certain weather, for a certain amount of time. But if the conditions change, virus titre would rise rapidly to easily detected levels (within days surely; perhaps within hours). So the concept that it could remain too low to detect for months or even years is mistaken. It could not (or at least, again speaking as a good scientist -- I should say there is no evidence for such a thing having ever happened, after more than 30 years of studying the problem). And so in a case like this, where the plant has been tested multiple times, in various weather, over multiple years, by multiple methods, I think we're just being good scientists in not claiming that we're utterly, absolutely certain a plant is mosaic-free. In fact, I don't believe there has ever been a case of a plant once indexed clean, that later showed up infected. Certainly, of the more than 300 varieties we've worked with, there is not a single known case of infection showing up later, and many of those have now been out in the industry for more than 20 years. I think that's a pretty good record (well, ok -- that's a perfect record!) Nevertheless, we'll continue to say that it has been tested and infection was not found, rather than directly claiming "It is virus-free." (Realize that in this case and in such discussions, one generally means "free of the viruses which cause symptoms of rose mosaic disease" when one says "virus-free;" there are other possible viruses that may not have been tested for, and we're not considering those).

'Reine des Violettes' was one of the many OGRs that were sold over the years by Roses of Yesterday and Today, when all of their stock was infected with the same mild strain of PNRSV, apparently from their source of 'Dr. Huey' rootstock. And since they were the only US source of many of the OGRs, we ended up with the entire crop in this country infected. Fortunately, that strain is really easy to remove by heat therapy, and 'Reine des Violettes' was one of our first successes when we started up our treatment program.

Thanks for the background info, Malcolm. That still leaves the original question...who has a VI RdV? How "safe" is the presumption that ordering someone's stock of it will yield a treated plant for her garden? It's great that has been treated and released as VI, but without that information stated by the nursery offering it, how would one know? Kim

The three I know of who have our strain would be Vintage, Antique Rose Emporium, and Heirloom. I don't know if Heirloom still carries the variety.

Malcolm, thanks for all the info. It is reassuring.

Can you post the names of all the varieties that you have treated? Or is there perhaps a URL where they are listed? I would be most interested in knowing which roses have gone through your cleaning program as well as which nurseries might have them.

Btw I bought my RdV early this year from Greenmantle. I don't recall if Marissa said where she got it, but I know she tries to stock roses that are clean. Mine has shown no signs of RMV, and I do look for it in my plants.

I have several plants in my garden that have *very apparent* virus symptoms including a Chrysler Imperial that came in a body bag (I keep it potted), an old grafted climber (unidentified), and Cl. Cecile Brunner. Cl. Cecile Brunner this year threw some canes in spring, and even into the heat of summer, with some of the strangest virus symptoms I've ever seen. Instead of strong yellow mosaic patterns, these are starkly white. This showed up after a radical change in feeding, and the plant looked downright stressed. Boom it started producing canes with strong mosaic patterns which was quite a shock. It rarely, in the over 40 years I've seen it growing, shows even a single virused leaf. Multiple suckers of Dr. Huey are adjacent (which always show mosaic patterns in leaves except in summer), and it was also very close to a very virusy Paul Neyron (from Roses of Yesterday and Today) for over ten years, until Paul Neyron died.

Melissa

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.

Paul Neyron was another one of the first roses from RoYT that we cleaned up.

Great info, Malcolm, thanks! I bought my RdV in a bag from Home Depot about 6 years ago and I have to say I've never seen any signs of RMV on it. Besides that it sure is vigorous. The darn thing has out grown two trellises when it was still in a pot and broken the third (bigger still and metal to boot)now that it's in the ground. I do so love it though!

Seil, our ROY&T RdV grew vigorously here for almost exactly 20 years.
On the achievement of its 20th Birthday, it popped out all over with the signs of RMV, and promptly went tennies up and died.

Several people had postulated that it might be accidentally virus-free, but I was sure it just wasn't showing. And I was right.

Jeri

That's been the problem, Jeri. Symptoms often don't show for many years, decades, even. When I began growing OGRs, ROYAT was the prime source and everything they touched was likely infected before they touched it, and surely was once they had. That, and everything they sold had been treated with Galtrol to prevent symptoms of the crown gall they had everywhere. That, I SAW when visiting and was assured gall shouldn't be an issue because they treated for it before shipping anything. There were so many old, rare, unusual and interesting things they became, if not the ONLY source of, at least the prime source. They did the advertising through their wonderful catalog long before the Inter Net made shimmering, porn images of the beauties previously only described in poetic blurbs, common. What can you do when the only material you can buy has what you don't want it to have? It was something you had to learn to deal with and hope the plants lasted long enough to find some other potentially clean source. What really irked me was my County Ag Agent telling me on one of his import inspections (around the mid 1980s) some of the things they were on the watch for were San Jose Scale (as in San Jose, CA where it was named); RMV, as if we didn't have enough of our own. Dennis said if any imported rose showed those symptoms, he was to confiscate it immediately "to prevent infection into the American rose stock!" Wow! Thank Heavens they were SO diligent! LOL! My tax dollars at work! Kim

Malcolm, could you tell me whether some specific roses have gone through your cleaning program? I have heard in the past that there are no clean clones available of Sombreuil and Rose de Rescht and wondered about it. I'm considering getting Soupert et Notting and La Reine but haven't heard much concerning their RMV status. Have these roses been treated successfully? Thanks!

Melissa

"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."
From following thread:
http://forums2.gardenweb.com/forums/load/roses/msg022235431402.html
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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 innaugural meeting of a California rose plant grower's association meeing 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
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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
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The (formerly) excellent climbing floribunda Cl. Sunflare AKA Yellow Blaze was virus free when first introduced. I know because I had one. I moved to another house and planted a new plant of what had become one of my favorite roses. I soon saw virus markings, and was disappointed to see a noticable lack of vigor and reduced flower production in the new, virused plant. Is Cl Sunflare available anywhere virus free? I emailed RVR once and asked if their Cl Sunflare might be free of virus, but I never received a response.

I have a web page concerning whether viruses have been found to return to heat treated plants (and suggestions as to why).

I have recently updated it as some of the links were no longer active and some new links were found.
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I also have a second web page concerning the rose's (temperature dependent) immune system.

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

Here is a link that might be useful: link for heat treated virus return above

Here's the link to the UC Davis program list of roses they have heat treated and scions available for purchase. I think the deadline for ordering is in mid October. The web address is listed on the top of the document.

I've not ordered any of this material, but I know others here have talked about it. It sounds like fun.

Nastarana, I didn't see the rose you mentioned on their list but I may have overlooked it. Gean

Here is a link that might be useful: UC Davis list of heat treated cultivars

Here also is a link to a great article describing the program; it is on the website for the UC Davis foundation program.

Here is a link that might be useful: The Rose Clean Stock Program

Unfortunately the Davis pamphlet has not been updated since 2004.

Davis has recently published a paper (in which they used PCR to detect the virus) 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."

-------------------------------------------------
It would be nice, if (and when) they update the pamphlet, that they would include typical color pictures of what this virus infection looks like.

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

Looks to me -- if it ain't one virus, it's another. We're doomed.

I think I go back to my original position, which was that if I want a rose, and the only clones known are virused, I will grow it virused.

Jeri

Apparently a Ph.D. thesis investigation is under way at the University of Minnesota. This report recently appeared:

"During 2004-2007 six previously undescribed or uncharacterized viruses were identified in cultivated roses in the USA in the states of Minnesota, New York, Michigan and Oregon. These viruses have been assigned provisional names because their respective roles in the etiology of the diseases with which they are associated is undetermined and still under investigation. These six viruses are Rose yellow mosaic virus, Rose transient mosaic virus, Rosa rugosa leaf distortion virus, Rose yellow leaf virus, Rose necrotic mosaic virus and Rose chlorotic ringspot virus. These six viruses were first detected by transmission electron microscopy using partially-purified extracts of symptomatic rose leaf tissue. Subsequent testing based on virion properties and nucleotide and/or amino acid sequence analysis of viral genomic sequences led to the conclusion that none of these six viruses had been reported or described previously."
----------------------------
Please notice that instead of using ELISA for detection they used a transmission electron microscope.

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

I said I would not plan to comment here again, but since my previous statement has apparently been deleted, I think I must. Notice that none of the "new" viruses being mentioned here by Dr. Kuska are rose mosaic, and none of that discussion is in any way relevant to rose mosaic nor the subject of this thread. Rose mosaic has NOT been shown to spread by aphids nor other methods being suggested here. It is precisely as if we were having a truthful and fruitful discussion of HIV/AIDS when someone came along and insisted that the common cold, kuru, canine distemper, and mad cow disease were all the same thing, and MUST be discussed here, now, as the same thing. It makes no sense at all. Yet here it is. Sorry. The conversation has been hijacked.

Rose Mosaic is not the name of a single virus. It is a group name for viruses that exhibit mosaic symptoms. Please notice how many of the Minnesota viruses above have mosaic in their names.
------------------------------------------
Linked below is a 2004 article by MAREK S. SZYNDEL who some of you may recognize as the person who wrote the rose virus article in the Encyclopedia of Rose Science, pp. 180-189.
---------------------------------------------
It will be nice if someone presents color pictures of the "typical" symptoms for each of these mosaic viruses on, say the ARS website. (Unfortunately there may not be simple "typical" symptoms especially if a rose has a mixed infection.)
Below is the verbal description for one of the "new" ones (new does not mean newly created, only that it was newly recognized).
A 2006) U.S. rose virus with mosaic symptoms.
Title: Association of a previously undescribed filamentous virus with yellow mosaic disease of rose

Authors: B. E. LOCKHART (1), N. E. Olszewski (1)
(1) University of Minnesota, St. Paul, MN 55108, USA

Published in: Phytopathology 96, issue 6, page S70, 2006.

Abstract: "Yellow mosaic is an apparently unrecorded disease of rose (Rosa spp.) that was identified in New York and Minnesota in 2004¨C2005, Symptoms of the disease consist of yellow to bright yellow sectoring and mosaic on leaves.
Necrotic ringspots on stems, similar to those described for rose streak disease, were also observed on one cultivar. Filamentous virions 800 ¡Á 12 nm in size were observed by transmission electron microscopy in negatively-stained
partially-purified leaf tissue extracts form symptomatic, but not asymptomatic plants. The nucleotide sequence of a 1.7 kb fragment of the 3¡ä terminus of the viral genome was determined. Nucleotide and amino acid sequence comparisons revealed no close similarity to any previously described viruses.
The virus associated with yellow mosaic of rose was named provisionally Rose yellow mosaic virus (RoYMV).
------------------------------------------------

Here is a link that might be useful: MAREK S. SZYNDEL link

Recently a rose hybridizer visited the U. Cal Davis rose cleaning laboratory. The link below gives his summary.

Of particular interest (to me) is that Davis is able to get virus free roses from buds:
-------------------------------
"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."
------------------------------
This follows logically from the discovery around 2000 that the viruses were not distributed evenly in the plants.
------------------------------------
It would be nice if Davis looked at this further with the idea of optimizing the conditions (what time of year should one take the buds to get the best yield, where on the plants does one have the highest probability of having "clean" buds, would treatment of the virused plant with an aspirin (or other readily available chemical such as a commercially available harpin) result in more clean buds, etc.
If the odds can be increased, we may have a practical "home remedy" after all.

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

Nope, we're not talking many, many viruses causing mosaic. Just as we're not talking distemper nor the common cold nor any of a host of other viruses when we discuss HIV in humans. Any discussion of those other viruses on this thread is irrelevant.

The simple fact is that the "problem" of mosaic in the USA is caused almost always by a strain of PNRSV, and occasionally by ApMV. We're done now. There are no other viruses that cause "rose mosaic." That there are many other viruses that can attack roses, or that have been found in a rose (notice that this big list from HK was found for the first time, ever) -- that does NOT constitute the "problem" of "virus" in roses! And even if it did, it would be a different problem from "rose mosaic," and irrelevant to this thread's discussion.

The same is true about using buds to get clean roses. That it might work, occasionally, is utterly irrelevant to the current discussion. The writer is simply hijacking this thread to confuse the readers.

There are numerous methods that can be used to remove rose mosaic (the actual disease by that name, caused by PNRSV or ApMV and the only one at all likely to be bought by you at a nursery or ever seen in your garden.) Heat therapy happens to be the easiest, quickest, and cheapest, and has proven to be exceedingly efficient and effective. That's why we use it.

Again I would point out that all references above that seem to indicate that it does not work or that "virus" "comes back," are misinterpretations, talking about the wrong virus, talking about a crop other than roses, are direct misquotations or misrepresentations, or for some other reason are not relevant and truthful to the conversation at hand -- specifically and uniquely the management of rose mosaic disease in American grown roses. I would recommend that readers very carefully read the links provided above -- in every case, without exception, if you read carefully enough you'll realize that they do not demonstrate what the thread hijacker says they demonstrate.

I don't know what bizarre need the writer has to confuse and destroy all such discussions, but there it is -- that's exactly what's happening here.

It always seems odd that someone who has done precisely no work with this disease, ever, and who obviously doesn't understand any aspect of this disease, is constantly telling Davis (and me) what's wrong with us and what we ought to be doing. Yet that writer is without the first hint of a clue. Why are such attacks on this and other forums always occurring? It makes no sense.

Yet we continue to produce mosaic-free roses and make them available, and so the availability of mosaic-free roses in this country has improved dramatically over the last 30 years, despite the insults and ignorance. 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. But despite such rumors and despite all of the statements on this thread so far, rose mosaic disease has never been demonstrated to have come back in a heat-treated rose, and the common methods of indexing really do work. Notice that no one other than the argumentative poster here claims otherwise. That's important -- NO ONE ON THIS EARTH who understands and works with these diseases -- agrees with the poster above.

When a rose grower observes a mosaic infection on a rose, he/she has no way of knowing which specific virus or combination of viruses caused the symptoms. It is unfortunate that the group name RMV (and rose mosaic) is often misinterpreted to mean a given virus.

A recent Davis extension service article about rose viruses does not mention RMV or (rose mosaic) but instead is titled "Rose Viruses" and states the following: "There are eleven known viruses that infect roses."

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

"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."
--------------------------------
"This past year I bought Cornelia virused indexed but it has shown signs of being virused the whole year. Hopefully the seedlings come out well. I used it heavily as a seed parent. I only did a few crosses as a pollen parent only on females I had more than one plant of. Just using one of the plants just in case it did transfer viruses via the pollen."
---------------------------

The above quotes were taken from the link below.

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

Malcolm -- Have I told you lately that I love you???

:-)

Jeri in Southern California

I realize one cannot argue against insanity. So I rest my case.

malcom manners, would you consider adding Cl. Sunflare to your heat treat program? It is an excellent climbing floribunda. The non virused clone I once had was really splendid, grew up to the gutters the first year while other renowned climbers were still sulking. I had it in hot, dry CA, facing west and exposed to hot dry wind, and it still bloomed all summer. It is recommended in a book I read about roses for southern gardens so I am sure there must be a market for a cleansed clone. It has the same shiny green foliage as Cpt. Thomas. The canes are long and flexible, but grow up, not out, and are easy to train.