I have roses here that grew in my garden for 20 years, before I saw a faint sign of the virus I knew perfectly well had to be there. If they can do that, I'm not going to worry about it.

I'll give you an example. The last newly-introduced HT we bought was 'Secret.' We liked it so much, we bought three of it. As it happened, the three plants were from three different sources.

Over the years, we removed them, and replaced them with Old Roses. We removed the weakest grower first. Then, the next-weakest. The third plant was vigorous, grew taller than the others, and repeated more quickly, and we kept it for several years.

It was also the only one of the three that ever displayed RMV. In the early spring, it was downright decorative.

Jeri

"The following study appears to be the critical study for explaining why plant virus infections have high concentration at lower temperatures but are attenuated at higher temperature. This 2003 paper has been already cited by 254 more recent papers (according to Google Scholar).

The abstract contains the following: "Therefore, in cold, plants become more susceptible to viruses,.....".

The Introduction contains the following:

"Plant-virus interactions are strongly modified by environmental factors; especially by temperature. High temperature is frequently associated with attenuated symptoms ('heat masking') and with low virus content of virus-infected plants (Johnson, 1922; Hull, 2002). In contrast, rapid spread of virus diseases and the development of severe symptoms are frequently associated with cold air temperature (Hine et al., 1970; Gerik et al., 1990). Harrison (1956) has speculated that the virus content of a plant represents an equilibrium between replication and degradation and that the activity of the virus degrading system increases with temperature. However, the underlying molecular mechanisms of these effects of temperature are still missing. We hypothesized that RNA silencing might be the postulated virus degradation system and temperature modifies plant-virus interactions through the regulation of RNA silencing." (page 633 and 634))

In the Conclusion section (page 638), they state:
"We find that siRNA-mediated RNA silencing is temperature dependent in three dicot species, thus inefficient siRNA generation at low temperature is probably a universal feature of higher plants."

Please note that statements in a reviewed published scientific paper have to be approved by the editor based on the comments of the manuscript provided to him/her by the reviewers (normally at least 3)."
---------------------------------------
Since its discovery, RNA silencing has been reported in: "RNA silencing functions as an antiviral mechanism in plants, insects and mammals (Csorba et al. 2009; Haasnoot et al. 2007; Shimura and Pantaleo 2011; Wang et al. 2012). Antibacterial immunity has also been demonstrated to be induced by endogenous sRNAs in plants (Jin 2008; Katiyar-Agarwal et al. 2007."

http://forums2.gardenweb.com/forums/load/roses/msg0700560420854.html

"Organisms including plants, fungi and flies fight viruses using an elegant mechanism involving RNA snippets that mammals apparently ditched at some point in their evolutionary history. At least, that is what scientists thought ��" but two controversial reports published today suggest otherwise."

http://www.nature.com/news/mammals-chop-up-viral-rna-to-attack-infection-1.13600

I do live in a mild zone, though.

Evenie

My Earth Song is the one that acts ups periodically--leaves get all marked with zigzags--but that just happens sometimes. The rest of the time, she shows no symptoms whatever--so I don't waste my time getting upset about it.

Kate

I LOVE your name, by the way!

Pickering who states in their FAQ sheet that every rose they sell has been virus indexed to remove RMV. http://pickeringnurseries.com/pickering_nurseries__faqs.htm

Heirloom who state they sell only virus free roses on their site. http://www.heirloomroses.com/care/rose-virus/

If anyone is aware of any other currently operating nurseries actually addressing the virus issue, please make the information public. Kim

http://www.neworleanscitypark.com/botanical-garden

Their next sale is November 16th at the Pelican Greenhouse, 9:00am. The selection of roses is usually pretty sparse this late in the year so you might want to email Kathy at plants@nocp.org
to get the plant list beforehand.

And thanks!

"Infected plants with rose mosaic viruses show different
symptoms such as flower distortion; reduced flower
production, flower size, stem caliper at the graft union
and vigor; early autumn leaf drop; lower bush survival
rates; increased susceptibility to cold injury; and difficulty
in establishment after transplanting (Thomas, 1981,
1982; 1984; Moran et al., 1988; Wong et al., 1988).
Symptoms are highly variable and depend on the
growing season, temperature, species, cultivar and type
of viruses infecting the plant. (Horst, 1996)."

H.Kusks comment. Please notice all of the possible variables.

"Researchers led by Ding, who heads a lab in UC Riverside's Institute for Integrative Genome Biology, have discovered that, like plants and invertebrate animals, mammals use the RNA interference (RNAi) process to destroy viruses within their own cells.

Their findings will be published in the Oct. 11 issue of the journal Science."

http://www.sciencedaily.com/releases/2013/10/131010142743.htm

DA is doing next to nothing about RMV. I went to a rose program last year and one of the growers said to me that DA knew full well of his RMV problem but was too cheap to have any of his roses treated. I couldn't believe it and wrote to DA Texas. I posted the correspondence in another thread--will look for it and repost. I showed the response to Malcolm Manners, RMV expert at Florida Southern, and I think his reply to me referred to what David Austin was doing on RMV was "worthless".

Now I think I have some paperwork from the last order I got from the Antique Rose Emporium (they get some of their stock from Florida Southern) and there was a form from some Texas agricultural inspection agency, and in it it referred to them checking for RMV. I can't recall exactly what it said, but I have to wonder why they haven't come down hard on David Austin, if their own Texas laws indicate some type of prohibition on RMV. I'm going to look for that form, will post it if I do (think it is in a file.....).

IMHO nurseries selling roses with RMV are being highly unethical and dishonest. It is high time people stopped putting up with it. So the rose business is down? Seems like another self-inflicted wound to me. The biggies were also marketing/pushing/selling many very unhealthy roses (highly susceptible to things like blackspot and mildew) without a single care in the world at what the unsuspecting consumer had to deal with in keeping these sicklies alive. So why should they care about selling roses already infected with a disease complex, RMV (as more than one virus is involved)? Such roses may not be suitable at all for their intended purpose, as ordinary garden plants, in many locations throughout the country. In my area, roses with RMV tend to be very short-lived, in spite of my location not being particularly cold. Perhaps it is the scorching heat of the summer that stresses the already-weakened, sick plants, and they can't survive under these conditions for long.

As far as I'm concerned those who sell RMV-infected plants are due not the least bit of sympathy. If they won't clean up their stock, then maybe it is long past time they got heavily penalized by whatever state agencies guard against plant diseases plus those that provide protection for consumers against buying defective products. IMHO if more of the rose sellers had decided years ago NOT to sell RMV-infected roses, then the rest of the industry would have been compelled to clean up their acts. But because of the laziness of some, an unpleasant situation was allowed to continue. Imagine if all rose sellers had a policy on RMV disclosed on their website? If so, how many more consumers would be educated about the problem? If everybody had a policy of not-selling RMV infected stock, just imagine how many varieties could have been cleaned up? And with the higher volume of roses being treated (heat therapy or tissue culture), the price of the treatment almost certainly would have come down.

I'd like to ask forum readers to check the website(s) of those rose nurseries you buy from, and see if they have a RMV policy. Please post here what you find, and if the nursery has no such policy, why not ask them to add one?

Melissa

Melissa

1)
"Posted by Tessiess 9b, SoCal Inland (My Page) on Thu, Jul 19, 12 at 20:10
I have a little bit of info on the virus front. I wrote to David Austin in Texas earlier this year and asked about the virus status of their roses (will have to check my sent mailbox to quote exactly how I posed the question). All I got back was a short message from one of the staff to the effect he or she was asking someone higher up to answer my question. I never got that additional message, so the issue is unresolved as far as I'm concerned.
Aha found it! The message was sent on January 28, 2012 to US@davidaustinroses.com:

"Hi,

Can you tell me which of your rose varieties have gone through either the virus indexing program at UC Davis or the heat treatment program at Florida Southern College? I can find lists with many old and new roses
from various hybridizers and growers that have gone through these testing/treatment programs, but I can't find any David Austin roses on these lists. Is there a reason why?

Thanks,

Melissa"

On February 4, 2012 I received a reply that thanked me for my email and was told the person was, "checking with our stock manager on the correct answer for you and will be back in touch with you very soon!"

I haven't received any additional contact up to now.

Melissa"

2)
"Posted by Tessiess 9b, SoCal Inland (My Page) on Sat, Jul 21, 12 at 14:49
Kate, you are right. So I just sent off a reminder to David Austin Roses. We'll see if I get an answer.
Just out of curiosity, has anyone else contacted David Austin regarding the RMV status of their roses? If so, did you get a response?

Melissa"

3)
"Posted by Tessiess 9b, SoCal Inland (My Page) on Mon, Jul 23, 12 at 22:50
Well, this afternoon I received a response to my questions from David Austin Roses. I was thanked again for my inquiry and given an apology for the delay in replying.
Apart from those pleasantries described above, below is what I was sent.

Melissa

"I can confirm that our varieties have not gone through the virus indexing program at UC Davis or the heat treatment program at Florida Southern College.

The major problem is that the Rose Growing Industry does not have a clear understanding of how the Rose Mosaic virus is spread. A lot of research has been carried out in this field but no substantive conclusions have been reached.

Our decision not to use these two above treatments is that there is no proof that they eradicate Rose Mosaic Virus. We see many rose growing fields in the United States throughout the course of a year. It is true to say that we have seen evidence of Rose Mosaic Virus in all of these crops.

We find it most effective to rogue out any virused plants in the field to keep the virus to a minimum."

I sent this info to Malcolm Manners and on July 23 he replied to me privately. He refuted what David Austin roses wrote to me in detail. Anyone interested could write to Malcolm for this information--I won't post his whole email here without his permission. But I will post the sentence with the "worthless" comment:

"Nurseries that rogue their fields generally only remove symptomatic plants, and that is a worthless venture."

Susan, as to your original question of what percentage in commerce are virused, the latest information I have comes from the Great Rosarians of the World this year at the Huntington. On one of his slides Malcolm Manners wrote that in the 1970s over 90% of US roses were infected, some nurseries were trying to get rid of it, it is still quite common, and that currently he thought less than 50% are infected.

Melissa

Melissa

http://datcpservices.wisconsin.gov/pb/pests.jsp?categoryid=43&issueid=191

Considering Wasco, California's contribution to the RMV issue, wouldn't you think it virtually impossible (as well as highly hypocritical) for US to require nursery stock to be inspected for RMV before permitting it entry into our state? Kim

Jeri

The following link goes to my literature search as to where (and when) rose viruses were first observed:

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

------------------------------------------------
Plus, California would not know which virus was causing the observed symptoms without extensive testing. As has been amply illustrated the last few years many viruses cause mosaic type symptoms.

Here is one recent example:

Title: "Detection of Tomato ringspot virus in rose and almond in Fars Province of Iran"

Authors: M. SATTARY (1), F. Rakhshandehroo (2), J. Mozaffari (3)
(1) Islamic Azad University, Department of Plant Pathology, College of Agriculture and Natural Resources, Science and Research Branch, Islamic Azad University, Tehran, IRAN; (2) Department of Plant Pathology, College of Agriculture and Natural Resources, Science and Research Branch, Islamic Azad University, Tehran, IRAN; (3) Department of Genetics and National Plant Gene-Bank, Seed and Plant Improvement Institute, Karaj, IRAN

Published in: Phytopathology 101:S160

Abstract: "Field surveys were conducted to asses the incidence of Tomato ringspot virus (ToRSV, genus Nepovirus, Family Secoviridae) in rose (Rosa chinensis L.)
and almond (Prunus amygdalus L.) in Fars Province of Iran during 2009��"2010. A total of 100 leaf samples with viral disease symptoms were collected and analyzed by Double Antibody Sandwich Enzyme-Linked Immunosorbent
Assay (DAS-ELISA) and Dot-Blot Assay (DIBA) for the presence of Tomato ringspot virus (ToRSV) with polyclonal antibodies. Serological diagnoses were confirmed by Immuno Electron Microscopy (IEM) and bioassay. Results
indicate the presence of ToRSV in all surveyed gardens. Among the samples tested, ToRSV was found in 21% of roses and 10% of almond trees. By applying RT-PCR to ToRSV-infected rose and almond plants, the expected
330 bp DNA fragment for ToRSV was obtained from all the samples tested.
To our knowledge, this is the first report of ToRSV infecting rose and almond
plants in Iran."

By the way, I'm not sure what that "exchange rate" stuff is all about, but in all the times I have ordered from DA Texas, that subject has never come up on my billing in any way, shape, or form. What did you do that made it an issue on your billing?

Kate

" Unlike the currently known viruses that affect rose, the ilarviruses and the nepoviruses, that only show symptoms and are detected early in the growing season, these new viruses exhibit symptoms throughout the season and can be detected readily during the entire year."

H. Kuska comment. This normally means that these viruses have developed counter measures to nulify the rose's immune system response.

Title: Symptoms, transmission, and detection of four rose viruses

Authors: Mollov, Dimitre1, Ben Lockhart1, and David Zlesak2
1Department of Plant Pathology, University of Minnesota, Saint Paul, MN 55108 USA
2Department of Plant and Earth Science, University of Wisconsin-River Falls, River Falls, WI 55022.
--------------------------------------------
Abstract: Four previously undescribed viruses infecting cultivated roses were identified and fully characterized in Minnesota. These four viruses were transmitted by grafting from infected to healthy roses and found to be the likely causal agents of the diseases that they were associated with. Viruses were provisionally named after the characteristic symptoms in infected plants as follows: Rose yellow vein virus (RYVV), Rose yellow mosaic virus (RoYMV), Rosa rugosa leaf distortion virus (RrLDV), and Rose yellow leaf virus (RoYLV). Unlike the currently known viruses that affect rose, the ilarviruses and the nepoviruses, that only show symptoms and are detected early in the growing season, these new viruses exhibit symptoms throughout the season and can be detected readily during the entire year. Based on virion and genome properties it was determined that RYVV is a member of the family
Caulimoviridae, RoYMV is a member of the family Potyviridae, and RrLDV and RoYLV are members of the family Tombusviridae. Phylogenetic analyses suggest that these four viruses belong to distinct new genera in their respective taxonomic families. The whole genomic sequence of each virus was deposited in GenBank under the accession numbers: RYVV JX028536; RoYMV NC_019031; RrLDV KC166238; and RoYLV, KC166239. Reliable diagnostic protocols were developed for each virus by PCR for RYVV detection, RT-PCR, immunosorbent electron microscopy (ISEM), and indirect enzyme linked immunosorbent assay (ELISA) for RoYMV detection, and RT-PCR for both RrLDV and RoYMV detection.

H.Kuska comment. From earlier in this thread the following was attributed to Austin Roses: "The major problem is that the Rose Growing Industry does not have a clear understanding of how the Rose Mosaic virus is spread. A lot of research has been carried out in this field but no substantive conclusions have been reached.

Our decision not to use these two above treatments is that there is no proof that they eradicate Rose Mosaic Virus. We see many rose growing fields in the United States throughout the course of a year. It is true to say that we have seen evidence of Rose Mosaic Virus in all of these crops."

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

Additional H.Kuska comment. They stated there is no proof; you state that "there is proof". Please provide a link or links to what you consider as "proof" so that I can consider adding them to my web page on the subject of "Discussion of whether viruses have been found to return to heat treated plants."

At present this is the conclusion section:
"CONCLUSION

H. Kuska comments. What I stated in 2005 "It now "appears" (to me) that a combination of heat treatment and / or antiviral drug and tissue culture may "outrun" the virus. Notice I say "may" because this is a new field and there simply is too much that apparently is not yet understood/known to make definite statements. " can now be changed to:

It appears that the field has advanced to the point where scientists can be confident that micro sized growing tips (including root tips) meristem tissue culture techniques have been developed to "outrun" the virus (see 2009 Google Scholar search referred to earlier in this thread). Plus there are now highly sensitive (PCR and electron microscope) detection systems available to guard against the possibility that the virus concentration is not zero but just below the ELISA detection limits."

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

Please notice that I state "It appears". Thus, this is my educated "guess". Time will tell if Nature has any additional surprises such as recombination from fragments. And, my cited web page does not speak to the Austin's scientists comments concerning spread: "The major problem is that the Rose Growing Industry does not have a clear understanding of how the Rose Mosaic virus is spread. ".

I agree with Kim.

It is my position that if I want a rose, and I can only obtain it virused, I will grow it virused.

BUT for a company to charge high prices -- and to infect newly-bred roses in a time when there is no excuse for that -- is simply unacceptable in my eyes.

DA has nothing at this time that I would pay their price for, particularly considering that they have infected what they sell.

Jeri

All of the hooey presented above by that one poster is in grand error.

We do, indeed, know exactly how to cure rose mosaic. No one who actually researches that disease would disagree in any way. But the poster of all the hooey is NOT a rose mosaic (nor any other plant virus) researcher, and continues to exhibit an utter lack of understanding of plant viruses.

Such amazingly silly arguments are the very fuel that DA and others need to continue selling us diseased plants, when they could so very easily and relatively cheaply be selling completely healthy plants, that would in the long run grow better for them, making them more money.

That this one poster has seen no proof that current methods work is not our problem; a head firmly buried in the sand tends not to see much. The rest of us produce and distribute, or buy and grow, mosaic-free roses that never, ever later become infected. While new, improved testing methods are very cool, in this case they are unnecessary, since the "good old" methods are 100% effective. Newer PCR methods and other "modern" methods have NEVER ONCE shown a plant that tested clean by other methods actually to be infected with mosaic. This is assuming the tester did so under the proper conditions; comparing ELISA to PCR in the heat of summer might show a difference, but no qualified ELISA user would be so stupid as to do such a test. That's rather like demanding that we compare making ice cream in a freezer vs. an oven, and anyone who has not tried it in the oven is an idiot. The poster of such ideas seems to think that the actual researchers are mindless fools.

It is really sad that this silliness arises EVERY SINGLE TIME anyone on this forum mentions virus in roses. It serves no good purpose.

To be clear: Yes we do indeed know EXACTLY how to CURE rose mosaic, caused by PNRSV or ApMV (the specific disease DA's roses and those from other suspect nurseries have -- so why discuss other viruses???) Once cured, we have UTTERLY effective methods of testing for the presence of those viruses. 100% accuracy over nearly 40 years, at several institutions. NOT A SINGLE CASE if misdiagnosis, nor of disease "returning" at a later date has EVER been documented. Not one. Not by ANYONE.

Why do I bother...

Let me say, further, that I regret the shrinking of the rose industry has probably slowed down the cleaning and distribution of valuable virused roses.

Jeri

H.Kuska comment. My web page link has done exactly that.

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

Back to the statement by the Austin scientists: " The major problem is that the Rose Growing Industry does not have a clear understanding of how the Rose Mosaic virus is spread. A lot of research has been carried out in this field but no substantive conclusions have been reached."

H.Kuska comment: what does the reviewed scientific literature have to say on this point?
The following are quotes from a 2013 published New Zealand scientific publication.
"PNRSV is known to be transmitted mechanically, by root grafting and by seed (Abdel-Salam et al. 2008; Golino et al. 2011). The virus may be transmitted by pollen in rose although this hasn’t been fully ascertained (Kuska 2003). The high incidence of PNRSV in New Zealand is unsurprising as it is also vectored by the Western flower thrip (Frankliniella occidentalis) which is reportedly spread throughout New Zealand (Greber and Teakle 1992; Teulon and Nielsen 2005) and is known to infest many glasshouse crops (E. Milleza, unpublished data). "
AND
"Reports of pollen transmission of ApMV in rose are inconclusive (Kuska 2003), but in view of the characteristics of other ilarviruses, it is possible that ApMV could be dispersed by pollen."
------------------------------------------------------
The reference that they cite is: "Kuska H (2003) Can North American rose hybridizers use pollen from virus infected roses? Rose Hybridizers Assoc Newsl 34:7-10"

Please note that for a statement to appear in a reviewed scientific publication, it has to be the thinking of the authors, plus it has to be approved by normally at least 3 of their scientific peers (the reviewers) and by the editor of the journal.
-------------------------------------------------
http://link.springer.com/article/10.1007/s13313-012-0191-x#page-1
------------------------------------------------
I subscribe to a plant virus research paper alert service. What a surprise, this come yesterday.
http://www.cabdirect.org/abstracts/20133344990.html

" Like all plant viruses, PPV could not be controlled with treatments and that makes breeding of resistant cultivars and rootstocks a significant tool for limiting its spread."

I did a quick Google Scholar search that produced another 2013 reviewed scientific publication that stated: "For fruit trees, this remains the most, if not the only, viable option for the control of plant viral disease outbreaks in cultivated orchards, due to the difficulties associated with the use of traditional and conventional disease-control measures. "

http://link.springer.com/article/10.1007/s11248-013-9728-1#
----------------------------------------------
H.Kuska comment: I hope that these illustrate that the control of plant viruses is still a valid on-going area of scientific research.

Who are these "Austin scientists" referred to in the quote below (which, I might add came from an email sent to ME directly from David Austin Roses in Texas)?

---------------------------------
Back to the statement by the Austin scientists: " The major problem is that the Rose Growing Industry does not have a clear understanding of how the Rose Mosaic virus is spread. A lot of research has been carried out in this field but no substantive conclusions have been reached."
_____________________

I just looked at the original email, and the person who wrote to me made absolutely no claim to being a scientist of any kind. Their position in fact is in sales. You need to post a retraction.

Melissa

Melissa, you are correct that the person who specifically corresponded with you did not state that he/she was a scientist. You are also correct that he/she did not explicity say that they checked with their scientists. He/she stated that he/she would: "checking with our stock manager on the correct answer for you and will be back in touch with you very soon!" I do not know for sure if the stock manager's position or background is in sales. But, I doubt it. What came back was a scientific answer. It appears that I "assumed" that the scientific answer came from scientists. I cannot imagine that that answer did not come from scientists as I feel that it is an accurate scientific answer (except for "We find it most effective to rogue out any virused plants in the field to keep the virus to a minimum." ) That part could be accurate in a cooler climate rose field, but I doubt that it would be accurate in the heat of Texas. Possibly the answer came from scientists in England.
-------------------------------------------------
The thread that Millisa linked to has this from a northern rose grower, Pickering: A: "We are absolutely sure that we have no virused plants in our fields. The budwood we receive from our sources is Virus-indexed and therefore virus free. Aside from that, we cover many miles walking our field inspecting the plants for issues such as mislabeled/ stray plants and disease/ pest infestations. New varieties are heavily scrutinized. We want to make sure that the variety is a good one and to be sure that it is healthy and lives up to its description."

H.Kuska comment. Please note that Pickering states that they only virus index the understock, not the roses. For the roses they use the same "check the fields approach" as Austin.
---------------------------------------------------
Regarding Elisa and PCR, the link below is to a 2005 reviewed published scientific paper that compares Elisa and PCR for chrysanthemum virus testing. Please see Table 1.

Also, please look at the Conclusion section. We are talking here about virus indexing for clean stock programs. The following appears to apply (and, I feel follows logically from the results presented in Table 1): "However, for generating mother stocks tissue culture industries and nurseries should use RT-PCR indexed mother stocks."

H.Kuska addition. Apparently the full paper is not available to everyone. I changed the link to be to the abstract.

http://link.springer.com/article/10.1007/s10535-005-0152-0#

As I pointed out in the discussion of other published scientific papers, the reviewers and editor had to agree to that statement. Also note the use of the strong word "should".

Silly nonsense. All of it. To demand good science and then to stoop to such utter non-science is shameful.

All of my statements above stand, and any real rose mosaic researcher would agree.

H.Kuska comment. Apparently the 2013 papers' scientists, reviewers, and editor felt it was worth citing.
--------------------------------------
Regarding literature about possible pollen spread. This is one part of my 2003 paper stated: "The second study appeared in a paper published by J. B Sweet. He reported that PNRSV was detected in the pollen of Peace and Queen Elizabeth roses, and in 1 % of two batches of seedling Rosa multiflora rootstocks. As is typical of scientific caution (or at least should be), he points out that finding the virus in the seedlings is not a definitive proof of transmission through the rose seed. However, his statement should not be interpreted that he did not find non grafted seedlings with virus; it means that he cannot be sure that the infected seedlings came from infected seeds (the virus may have infected the seedlings after they were planted (infected shears, infection from thrips, etc.)). What it does show is that there was transmission of PNRSV to non grafted seedlings in 2 different batches. Since multiflora seedlings are grown together in a field, I think that one can exclude the possibility that the seedlings were infected by "root grafts to an infected neighbor plant". If one attempted to use this reasoning, one would be going in a circle logically i.e. one would have to explain how the infected seedling that supplied the root graft got infected."

Also, I included the following later: "In another paper which examined 10 R. damascena seedlings obtained from a Turkish nursery that did not have visible PNRSV virus symptoms and seemed to be healthy, ELISA detected that one of the SEEDLINGS was infected by PNRSV. Of course we do not know if the virus came from infected pollen or from an infected mother, but just like in the Swift multiflora infected seedlings: what it does show is that there was transmission of PNRSV to a seedling."

------------------------------------------------
The following written by Baldo Villegas states: "Some pathologists suspect that mosaic may be pollen transmitted which could prompt removal if other roses in the garden are valuable and not already infected.

-----------------------------------
Regarding the statement: "All of my statements above stand, and any real rose mosaic researcher would agree."

H.Kuska comment: The 2013 New Zealand paper was by "real" rose mosaic researchers.

:-/

~Christopher

The first paper is Sweet�s Journal of Horticultural Science report referred to earlier. He germinated seeds from the two infected plants (36 seedlings from one and 24 seedlings from the other. None showed visual symptoms and 5 random samples from each were grafted on P. Persica GF 305 seedlings (virus test plants) and did not test positive. There are several reasons why I do not consider this report definitive: 1) 10 grafting tests is too small a sample size, 2) the use of visual symptoms on 36 samples can now be considered as both too small a sample and to also be deficient in test sensitivity (often infected plants do not have visual symptoms), and 3) if the infected two bushes were randomly positioned in the same field as 198 healthy ones; it is probable that the pollen came from the healthy bushes (this point will be discussed further later).

The second virus-seed transmission test paper was published in 1984, by B. J. Thomas. He reports on three different experiments that could provide some information regarding virus-seed transmission. In the first experiment he crushed 10 seeds from each laboratory infected virused plant with hips, and could not, using ISEM, detect any PNRSV in the seeds (he did not state the number of batches examined). In the second experiment he examined, with ISEM, 1067 seedlings grown from seeds harvested from the infected bushes and found no PNRSV infected plants. A possible explanation for the failure to detect PNRSV in the seeds or resulting seedlings is that the seeds may have also (like Sweet�s samples) been unintentionally produced from non-infected pollen. The roses utilized were all species roses, R. canina, R. canina, var. Brogs, R. corymbifera, R. multiflora, and R. rugosa. Species roses are normally self-sterile (see footnote 2). He should of been examining the seeds from the non virused bushes that were located between the two infected bushes or better yet did hand pollination with infected pollen..

The third paper appeared in 2007 and was published by the U. California Davis. They did not find any pollen/seed transmission, but they did not conduct any experiments where they used virused pollen to produce seedlings. They did examine open pollinated seedlings of virused mothers (page 218 of full paper "Ripe rose hips were harvested from the following seven varieties that tested positive for ApMV and/or PNRSV by ELISA: Rosa hybrida �Don Juan�, �Fourth of July�, �Red Fountain�, �Arizona�, �Queen Elizabeth�, and �Earth Song�.") In addition a hot summer climate is not the ideal place to study any type of above ground transmission as the rose's immune system has been found to be effective against PNRSV at higher temperatures. At high temperatures the virus concentration has been found experimentally mainly in the below ground parts of the plant. See the following link: http://home.roadrunner.com/~kuska/high_temperature_effect_on_pnrsv.htm"

Of course on a forum you have the option of presenting what you feel that I am ignoring.

----------------------------------------
Help-Me-Find is a web site that is very useful. For rose mosaic virus they utilize a link: "In the USA, many state agricultural cooperative extension services have excellent online information about RMV with good pictures. One example is the pdf file from New Mexico State University Cooperative Extension which can be downloaded at this link."

Unfortunately, their link is outdated. Here is the new one.

http://aces.nmsu.edu/ces/plantclinic/documents/consulting-rosarians-2013_rose-diseases.pdf

This is what it states about possible pollen transfer:
"Rose Mosaic Virus

"Little evidence of spread in the garden
��"
May be through pollen but spread is incredibly slow"

H.Kuska comment. In New Mexico I would not be surprised if pollen spread is incredibly slow or even zero due to the temperature behavior of the immune system. I am recommending research in cool climates.

Jeri

So much bad "science" quoted above. :-(

Or how many people have decided to "wait and see" if maybe just maybe some one in their block used an herbicide and that it really isnt RRD and ended loosing not only their own roses but infected everyone elses?

Maybe it would make some sense if the one poster thought before posting if the posts helps, hurts or confuses.

The following is the abstract of a 2007 M.S. Thesis

"This study was carried out to detect PNRSV on rose in Şanlıurfa province and its districts in 2005. Sampling was made in May. Samples were collected from public gardens. 19 samples expressing virus diseases were tested for PNRSV by ELISA and RT-PCR. The diseases incidence, as percentage of total samples for PNRSV, was found 21.05% by ELISA and 31.57 % by RT-PCR. PNRSV was determined as a new virus on rose in this region."

H.Kuska comment. The average high in May is 83,8 deg F, the average low is 60.4. So of the 19 samples that exhibited virus symptoms Elsia reported that 4 were infected by PNRSV while PCR found that 6 were infected by PNRSV. The fact that there were 2 samples that were found to be PNRSV free with ELSIA but positive with PCR is consistent with studies with other plants that also showed that PCR can detect viruses below the ELSIA detection detection limit (see my web page on viruses returning to heat treated plants).

A Master's Thesis is conducted under the supervision of a faculty member.
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My link also included a quote (with link to a Davis document: "Occasionally, disease may not be detected in only one growing season, so nurseries and growers are cautioned to inspect their plants carefully prior to propagation."

Please notice that this does NOT say something like: it is a theoretical possibility but has never happened. It states OCCASIONALLY it does happen.

After you read that please go back and read what was published by 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. about the detection of viruses in plants in general.
http://ucanr.org/sites/UCNFA/files/62197.pdf
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Have you ever considered that the few and far between studies you pull to support your views may be presenting anomalous results? If one study finds A, and that study is repeated several times but A could not be found again, the proper interpretation is that A occurred because of some error in the experiment, NOT that the other repeat experiments ALL had errors because they FAILED to find A.

My Behavioral Neuroscience professor told us that when we read scientific papers (at least three a week, every week), the first time something is found, we should think "huh...interesting..." but seek further investigation. If the findings could not be repeated, or were actually refuted with further studies, then the original shouldn't receive much (if any) attention. Only when experiments are repeated and similar results are found again should the claims be integrated into the bank of "what we know." Biology is messier than Chemistry -- the pieces don't always react the same way every time, hence the need for repetition and statistical analysis to negate the possibility of errors or anomalies. This is even further emphasized in the area I studied -- psychology.

:-)

~Christopher

We are talking about a rose tested clean by ELSIA but found not clean by PCR. I have given references to the same comparison for other plants and what Davis and J and P have stated for roses. Regarding your statement: "Only when experiments are repeated and similar results are found again should the claims be integrated into the bank of "what we know."" I have presented the similar results.
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In another thread I pointed out that a USDA cosponsered paper had warned about virused ornamentals spreading to other plants.

From the abstract of a new 2013 paper:

"Prunus necrotic ringspot virus (PNRSV) affects rosaceous plants worldwide. In 2011 and 2012, 50 symptomatic bindweeds (Convolvulus arvensis) were collected from rose gardens in Alburz, Mazandaran and Tehran provinces of Iran. Samples were tested for the presence of PNRSV using DAS-ELISA and dot-immunobinding assay (DIBA) with a polyclonal antiserum (Agdia, USA). PNRSV was detected in 38% of the samples with symptoms such as line pattern, mottle and marginal necrosis in all visited regions."

I feel you've come to the point of simply arguing to argue, ignoring the consensus reached by balancing ALL studies, and offer only confusion rather than any usefulness on this topic. I advise anyone else to simply skip past ANYTHING you post regarding viruses from this point on. And with that, I'm not "feeding the monster" anymore.

:-I

~Christopher

See the link below for ApMV.

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Also from the same paper:
"Natural hosts of ApMV include apple, rose, hazelnut,
horse chestnut, raspberry, birch, hops (Rybicki, 1995),
stone fruits (Myrta et al., 2003) and strawberry (Tzanetakis
and Martin, 2005)."
H.Kuska comment: as you can see, the list includes agricultural products that are of interest to the USDA.

You may also find the discussion in this paper about the modes of transmission of this virus interesting.
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Hopefully most of you are familar with Professor Tzanetakis since his group was the group that finally identified the rose rosette virus. The strawberry reference to him listed above can be read at:
http://apsjournals.apsnet.org/doi/abs/10.1094/PD-89-0431A

H.Kuska comment. No documentation. I do not know of a visual test being considered to be definitive . A visual observation may mean that the rose has PNRSV. It could mean that it has another virus (that the specific ELSIA or PCR test will not detect), or it could mean that the plant has a nutritional deficiency.

Here is documentation for my statement: "Some rose samples were noted to have symptoms such as chlorosis, mottling, spots and necrosis, but no viruses were detected. Previous reports have shown that symptom expression, virus distribution and virus detection can be influenced by several factors including cultivar, changing seasons/weather and growing conditions (Manners 1997; Sala-Rejczak and Paduch-Cichal 2005; Sertkaya 2010; Wong et al. 1988). It is therefore possible that the time of year or the environmental conditions prior to and during sampling may have contributed to a reduced titre of some viruses to a level too low to detect. The inability to detect viruses could also be attributed to uneven distribution in the rose plants. Alternatively, it is possible that other viruses were present in the roses which have yet to be described, or that symptoms similar to those caused by viruses were caused by nutrient deficiencies in the roses (Horst and Cloyd 2007)."
H.Kuska addirional comment. Even the thesis' own data show that a visual test is insufficient. They collected "19 samples expressing virus diseases". (For this discussion this was an unfortunate choice of words as all the visual test could tell them is that the plants exhibited "virus like" symptoms.) For 13 of those samples no PNRSV was detected by either method. The documentation that I provided here explains why. The point is that 2 samples that ELSIA reported clean of PNRSV were found to be infected by PNRSV when tested by PCR.

H.Kuska comment: in science we are trained to look at the complete scientific literature. Earlier in this thread, Thu, Oct 17, 13 at 20:30, I gave an example of that in my paper.

If anyone is aware of any papers that challenge the idea that virus levels below the level of detection are a real problem in virus free certification, please present them.

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Please note that we still have no comment on: " My link also included a quote (with link to a Davis document: "Occasionally, disease may not be detected in only one growing season, so nurseries and growers are cautioned to inspect their plants carefully prior to propagation."

Please notice that this does NOT say something like: it is a theoretical possibility but has never happened. It states OCCASIONALLY it does happen."

More evidence that supports the Davis statement (for different plants than roses, but still suportative of the concept that virus levels can be be below the level of detection.)"

"However, totally 38% of pome fruit and 67% of sweet cherry seemingly virus-free clones after the first round of testing were positive in retests for the same viruses as in the initial plants. In the case of this material, the treatment probably depresses the amount of viral particles temporarily below the threshold level of detection of used diagnostic methods. In the course of further cultivation, the virus recovered-up and re-accumulated to a level of detection. Obtained virus-free plants will be included in the established system of certification of initial plant material after repeated testing and long term observation."
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"Our roses are grown on virus free root stock and inspected regularly throughout the season for the presence of virus. While we cannot guarantee complete freedom from virus, in the very unlikely event of you receiving an imperfect plant, we will, of course, replace them free of charge. Simply phone our toll-free number to request a Replacement Form and it will be mailed out to you right away. Your kind feedback will assist us in identifying and correcting occasional problems."

H.Kuska comment: so Austin's present statement is very similar to Pickering's statement. In practice the cooler climate at Pickering may make it easier to spot virused plants than the hotter climate at Austin's fields.