Conerning contaminating other roses by above ground spread, the following link gives a description of an aphid spread rose virus found especially (so far) in California. http://home.roadrunner.com/~kuska/rose_spring_dwarf_virus.htm ---------------------------------------- The following is what I have summarized for northern gardeners and PNRSV, a very common rose virus in the U.S.: http://home.roadrunner.com/~kuska/info_about_virus.htm ------------------------------- Underground root to root transfer has been shown to also transfer rose virus. http://forums2.gardenweb.com/forums/load/roses/msg0710595423501.html ---------------------------------------------------- ---------------------------------------------------- Concerning transfer of rose viruses through seeds. The following link gives the information that I have found concerning infected Blackberry chlorotic ringspot virus (BCRV) rose seedlings. http://home.roadrunner.com/~kuska/Blackberry%20chlorotic%20ringspot%20virus%20(BCRV).htm ----------------------------------------------- The following is an undated version of an article that I wrote for the Rose Hybridizers Newsletter: "Can North American rose hybridizers safely use pollen from PNRSV infected roses?" http://home.roadrunner.com/~kuska/rose%20virus%20and%20pollen.htm

buford, a rose can have cryptic viruses in their lineage since these viruses are passed through the seed. A cryptic virus has been found in RRV infected multiflora. http://www.sipav.org/main/jpp/index.php/jpp/article/view/664/451 I think I read recently that one of the blueberry type viruses that also infects roses and is passed through the seed has been found in RRV infected roses. Perhaps either of the above is what you heard. Often virus coinfections are much "harder" on a plant's immune system than a single virus infection. Here is a link that might be useful: link to cryptic virus discussion

Taoseeker stated: "It would be interesting to compare a few old varieties with the heat treated ones." I am not sure if you are refering to what what I think you are. If you are interested in whether a virused but then heat treated plant does better or worse than one of the same variety that was never virused, this is my response. Plants are very complex, it is possible that the virus and / or the heat treatment may have affected other mechanisms (could be positive or negative). There are many types of examples but since a very recent (2009) example of the "expression of heat stress proteins" has been studied in a rose, I will present that example. The actual research paper is very technical. The paper is at the following link: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=6203748 Rather than looking at the specific details most readers would probably benefit more from the following summary of the field: http://www.cspp.cn/Annual2009/upload/pub09.pdf Please notice the statement: "It is known that rapid heat hardening can be elicited by a brief exposure of cells to sub-lethal high temperature, which in turn provides protection from subsequent and more severe temperature." This does not "prove" that heat treated roses will have better heat resistance. Maybe a longer term of high temperature will result in other effects (positive or negative). I am presenting this to indicate that one cannot assume that other variables are being held constant. It is possible that effects may not show up till years later. Some "cured" polio victims are now finding that many years later problems related to the polio are appearing. -------------------------- The effects of a virus infection can be very unexpected. The following link discusses the observed effect of a virus on aphid population (not done on roses): http://www.springerlink.com/content/uw13564v21223876/ I have posted several times about my experince with a virused Culbert Grant from Pickering. Up to then my best Climber was Illusion. This new Culbert Grant bloomed and grew much better than Illusion all summer. I was very excited. That winter I received a letter from Pickering that it was virused and that they were pulling it off the market. That spring it was dead. Scientists at Cornell University surveyed approximately 2500 roses by visible assessment. They found that 166 had virus symptons: http://www.actahort.org/books/234/234_53.htm From the abstract, it does not appear that anything unusual was observed, but from the full paper a number of unexpected results were reported such as: "Total flower cut weight and total number of flower cuts with nonsymptomatic foliage was greater from PNRSV (severe) inoculated rose plants than from healthy control plants. The data revealed also that PNRSV (severe) and ApMV (severe) inoculated plants outyielded the PNRSV (mild) inoculated plants, which in turn outyielded the healthy tissue inoculated plants. These results were unexpected since reduced yields would be anticipated from virus infections." They then discuss some "maybes. one of these is: "Another speculation is that the initial stage of viral infection stimulates host metabolism by competing and utilizing the host ribonucleic acid polymerases for ita viral replication." i.e. The virus infection may be causing the rose to grow better. ----------------------------------------------- The following non rose paper may be of interest: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=6203748 Explanation of the sympols: (VT) I assume that (VT) means heat treated since I found this using heat treatment as a key work. The abstract is not clear. (My literature search service says the full paper can be down loaded but when I try it states that it is too new and has not been uploaded yet.) (V) is virused infected. (VTR) is virused reinfected. Just to highlight one of the observations: "V plants produced big tubers that weighed more than those from VT plants."

Science can move rapidly. The abstract below was presented at the 2012 Petria -22nd International Conference on Virus and other transmissible diseases of Fruit Crops. Now that it is recognized that plants have an immune system against viruses (RNA Silencing) a logical next step is to use genetic engineering to add more RNA silencing molecular sequences. In the abstract below please note that they recognize that both low temperature and mixed virus infections can decrease the effectiveness of the plants natural immune system: "Since it’s known that some abiotic - low temperature - and biotic stresses - mixed viral infection - could have a detrimental impact on RNA silencing-mediated viral resistances," ---------------------------------------------------- Title: Robust and Wide Spectrum RNA SIlencIng Mediated Resistance TO PLUM POX VIRUS Authors: E. Di Nicola-negri(1), M. Tavazza(2), V. Ilardi(1) (1)Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Centro di Ricerca per la Patologia Vegetale, Rome, Italy; (2)ENEA CR Casaccia, Via Anguillarese, 301, 00123 Rome, Italy Published in: Petria, Vol. 22 (3), 2012, 123-459, Abstract: "Plum pox virus (PPV) is a quarantine virus that causes sharka, one of the most important diseases of stone fruits worldwide. Seven PPV strains have been characterized, of which PPV-D, -M and Rec are the most important from an agroeconomical point of view. The best agricultural sustainable approach to prevent sharka disease consists in developing PPV-resistant plants. In this context we have shown that Nicotiana benthamiana plants transformed with PPV-M sequences (PPVIsPaVe44), covering the 5’UTR region, P1 and HC-Pro genes and arranged to express self-complementary ‘hairpin’ RNAs, are immune to the homologous PPV-ISPaVe44. However, as the RNA silencing-mediated resistance operates in a sequence-specific fashion, transgenic plants harboring the four hairpin constructs were also challenged with viral isolates belonging to different PPV strains. All the transgenic plant lines were resistant to PPV-D, ��"M and Recc strains. Moreover, the transgenic plant line harboring the 5’ UTR/P1 sequence was also resistant to isolates of PPV-EA and PPV-C strains that are distantly related to ISPaVe44. Since it’s known that some abiotic - low temperature - and biotic stresses - mixed viral infection - could have a detrimental impact on RNA silencing-mediated viral resistances, 5’ UTR/P1 plants were challenged with PPV under different conditions. Transgenic plants were resistant to PPV infection both at high (30°C) and low temperature (15°C). Furthermore, no susceptibility to PPV-Was observed in 5’UTR/P1 plants previously inoculated with Potato virus Y (PVY), Cucumber mosaic virus (CMV) or Artichoke mottled crinkle virus (AMCV) suggesting that prior virus-mediated expression of HCPro (PVY), 2b (CMV) and P19 (AMCV) RNA silencing suppressors was not able to defeat PPV resistance. The overall data suggest that the 5’ UTR/P1 hairpin construct can be profitably used to confer resistance to the sharka disease in Prunus species." The above is taken from a 338 page PDF document that gives the abstracts and/or full papers that were presented at that Conference. Here is a link that might be useful: Link to 338 page PDF document (long download)