Brief Summary of Minutes of Annual Meeting

WERA-20 Annual Meeting
McMenamins Kennedy School, 5736 NE 33rd Ave., Portland, Oregon
July 11-14, 2011

The meeting was called to order at 1:00 PM by chairman, Joseph Postman. Minutes were to be taken by Simon Scott who volunteered to host the next annual meeting in South Carolina on some date in 2012 that takes into account the potential diseases, temperature, and humidity. Participants introduced themselves and Ralph Cavalieri provided a few comments as the administrator of the project. He gave a brief explanation of the role and function of WERA 20. The hatch act authorizes 25% of the funds for multistate research. WERA 20 is a coordinating committee in which people with similar research interests can co-ordinate efforts. It is less restricting than formal research projects. The committee rewrites its project every 5 years. WERA 20 has been rewritten and the project is approved from October 2011 to September 30th, 2016.

Administrators at NIFA are not sure of the outcome of current budget negotiations. The house cut 12-13% from the budget however it is expected that the senate will reinstate these funds.

State Reports began: Brief synopses of the information are presented in the minutes and may be supplemented by the annual reports from individual states.

Lydia Clayton/Alex Karasev, Idaho.
Reported on surveys of viruses in grape vines completed over the past 3 years. There are approximately 1600 acres of grape vines in Idaho with about 25 of these being located in Northern Idaho. The industry was the first to be established in the west in 1864 but then disappeared because of Prohibition and began to re-establish itself in 1970. An initial survey of viruses completed in 2008/2009 by Karasev, Martin, and Rayapati detected Leaf Roll (3) and the rugose wood complex in both Northern and Southern Idaho. A survey by ISDA indicated that only the grape mealy bug (Pseudococcus maritimus) and not the vine mealy bug (Planococcus ficus) were present in the state.

2009 survey 100 samples from 7 counties, 2,000 individual tests coordinated with the ISDA survey. 6% of samples infected with one or more grapevine leaf roll viruses also the virus was detected in 1 sample that had been collected from 25 retail nurseries. No grapevine fan leaf virus was detected. Grape mealy bug exists everywhere. Infestations of immature and adult females have been observed.

2010 survey 15 vineyards plus 1 abandoned property, 170 leaf samples Grapevine leaf roll 3,4, and 5 detected. Also Grapevine A, Grapevine B and Rupestris stem pitting associated virus. The nepoviruses Arabis mosaic virus and Grapevine fanleaf were not detected.

Certification regulations are being revised as the current regulations date from the 1970s.

Elina Coneva, Alabama
Surveys of blackberry viruses were completed in 2007- 2008. In 2007 15 sites in 8 counties. TRSV, ToRSV, RBDV, and INSV detected. All 4 viruses in almost all sites. Cultivar Navaho 60% multiple infections. Difficult for growers to find good plants.

2008 - 2010 Xylella fastidiosa bacterial leaf scorch of blueberry, also citrus variegated chlorosis in citrus in Albama recorded. Sharpshooter vectors (Homalodisca vitripennis ) present. Botryosphaeria dothidea stem blight of blueberry present in up to 40% of plants. Participated in an E Extension grant working with LA, USDA, MS, NC. Thishas produced the website www.extension.org/blueberries.

Ken Eastwell, Washington
Described work on Cherry leaf roll virus (CLRV), Little cherry virus and rusty mottle virus. CLRV was first detected in cherry in WA in 1998. It developed from the initial find to an industry-wide problem that continues to spread. Transmission is not well defined. In other species (Walnut) it is pollen-borne. In cherry there appears to be a single infection followed by rapid localized spread through root grafting. The type of irrigation used affects the incidence of the virus. 2006 -2007 pollinated large numbers of flowers but although the virus could be detected in 27-50% of the pedicels there was no movement to the tree. It is possible that the presence of a second virus (PNRSV ?) is needed to facilitate transmission. In Franklin County 83 out of 95 samples were positive this year. The rootstock Colt is hypersensitive to CLRV but Colt does not produce good trees.

Bing and Sweet Heart Constitute 61% of the trees in WA.
Little cherry virus 2 was widespread in 2010 and trees showed symptoms. This was repeated in 2011. LCV 2 is transmitted by the apple mealybug. However the grape mealy bug is moving from the south and it is a vector of Grapevine Leaf roll 3 which is closely related to LCV 2 at the molecular level.
Necrotic Rusty mottle has been showing enlarged veins in some hosts.

Brook Edmonds, Oregon Dept of Agriculture
Brook introduced herself as the replacement for "Sid" Sedegui. The testing for fruit tree viruses is being completed using ELISA, not the molecular probes favored by Sid.

Ramesh Pokharel, University of Colorado, Grand Junction.
Described work on Cherry rasp leaf virus (CRLV) in conjunction with Ray Mock at USDA, Beltsville. He reported a finding of CRLV on sour cherry and noted suckers originating from removed trees that displayed the classic symptoms of rasp leaf disease. Surveys had been completed in 2009 and 2010. CRLV present in 62% of the samples. Cherry virus A present in 53% of the samples. Analysis of the sequences of PCR amplicons showed little variation among isolates of CRLV. CRLV was also detected in asymptomatic trees. He also reported on a rootstock , variety, and management trials of CRLV.

Lauri Guerra, Washington Dept. of Agriculture, Prosser

John Hu University of Hawaii, Honolulu
John described work with Citrus Tristeza virus in Hawaii. Citrus has been grown in Hawaii since 1792. Citrus tristeza stem-pitting was first seen in 1952. The Brown citrus aphid vector of CTV is present in Hawaii. Citrus has become more important as land used previously for growing sugar cane and pineapple has become available and a replacement crop is needed. Both the decline form and stem pitting forms of CTV are present in Hawaii. The incidence of the virus was determined using PCR and tissue-blot immunological assays. CTV is widespread with an overall incidence among the islands of approx 75%. Samples were tested using specific PCR primer pairs to identify the T3, T30, T36 and VT genotypes of the virus. A CP transgene was constructed using sequences of isolates from Hawaii and other countries and was predicted to be effective against 95% of all reported isolates. This was used in a multiple post transcriptional gene silencing system to control the virus using Mexican Lime as the host into which the transgenes were inserted. 58 plants are being tested for resistance and are being challenged using 5-10 brown citrus aphid per plant to inoculate the virus.

Ruhui Li, USDA-ARS, Beltsville, Maryland
Gooseberry vein-banding disease has been associated with 3 possible viruses: members of the genera Clostero - Rhabdo and Badna. Goosebery vein-banding virus is a distinct species in the genus Badnavirus. Jonkheer-Van-tets is a better indicator for GVB than Amos Black. Lui reported on pathogen elimination in tissue culture describing the elimination of Cherry Virus A by using Ribavirin in culture medium. Peach latent mosaic viroid could also be eliminated in tissue culture using ribavirin.

This session finished at 5:00 PM and dinner was served at 6:00 PM.

Wednesday 13th July.

Field trip to Hurst berries, packing fresh berries; North American Plants - Tissue culture facility, Sokol Blosser Vineyard and Winery, Dundee, Oregon - Lunch and wine tasting, Oregon State Field station - Blueberry Field day.

Thursday, 14th July, 2011.

Margarita Licha , USDA-APHIS, Beltsville, MD
Provided a review of her program at Beltsville. Post entry quarantine for pome and stone fruits is available for material from only 5 countries in Europe. In 2010 the program received 13 Pome accession s and 62 prunus accessions under this program. Most of these were from the Netherlands. The pathogens found in Prunus were Prune dwarf virus, Prunus necrotic ringspot virus and American plum line pattern virus Hop stunt viroid and Peach latent mosaic viroid. 209 releases of material were made in 2010 Total of 789 releases from the program since 2007. A recipient of a release has to approve destruction of material maintained at Beltsville. Thus material has to be maintained in Beltsville until this approval is received.

Bob Martin USDA-ARS, Corvallis, OR.
Described work on Blueberry necrotic ring blotch virus aka "Funky spot". The virus occurs in both Highbush and Rabbiteye blueberries. It was formerly thought to be caused by a Septoria but the rings occur on both surfaces of the leaves. It has been detected in GA, NC and SC. There is transmission in the field. Plants do not show symptoms during early stages of growth but they appear later in the season. The virus has a multipartite genome with 4 RNAs. Other viruses mentioned were: Raspberry leaf mottle virus (a closterovirus that is aphid transmitted), Raspberry latent virus a novel reovirus, Rubus yellow net virus (a badnavirus). Blueberry premature fruit drop disease spreads in British Columbia. It cause 100% fruit drop. There is a cryptic virus associated with plants infected with the disease but it is probably not the causal agent. Blueberry mosaic virus is a putative Ophiovirus, and Blueberry bronze leaf curl disease is associated with a tentative closterovirus.

Carol Masters Canadian Food Insp. Agency, Sidney, BC
The PPV program in Canada is no longer an eradication program. Henceforth it will be a management program. Funding was not received until June 2011. This year 20,000 samples will be collected: a reduction from the 120,000 samples of previous years.

PPV-W has a host range almost identical to PPV-D but P. persica is a reluctant host and the virus does not infect nectarine. Grapevine A was detected in material imported from France.

Joseph Postman, USDA-ARS, Corvallis, Oregon.
Described work on Medlar (Mespilus germanica L.) in which ACLSV produces ringspot symptoms. Medlar may be immune to Apple stem pitting virus. Cherry leaf roll virus in elder berry was discussed. A previous report of Apple mosaic virus in pears was refuted. The symptoms were associated with Pear vein yellows.

Erich Rudyj , NCPN Riverdale, Maryland
Presented the current status of the National Clean Plant Network.

Simon Scott, Clemson University, Clemson, South Carolina
Refered to continuing work on the viruses and viroid present in Ta Tao 5 germplasm. The germplasm has been used to achieve a significant bloom delay in peach in the southeastern USA but the relative contribution to the delay of the 2 viruses and the viroid infecting this germplasm is still being determined. Phony Peach Disease associated with Xylella fastidiosa is re-emerging as a problem in some areas of SC. The range in which the disease typically occurred is expanding. The bacterium cannot be detected by either RT-PCR or Real-time PCR in a proportion of the trees displaying classic symptoms (luxuriant growth and a flat top). Research is ongoing to determine the distribution of the bacterium in the tree. Previously researchers have suggested that the bacterium occurs at higher concentrations in root tissue.

Sudhi Sudarshana (mysore.sudarshana@ars.usda.gov) USDA-ARS, Davis, California.
Presented the results of a Grape vine leaf roll survey completed at Davis by Rodrigo Almeida. The majority of isolates examined were GRLV 3. He then described his work on Almond Brown Line and several phytoplasmas causing distinct disease in stone fruit. He also reported on work with Cherry stem pitting disease.

James Susaimuthu (James.Susaimuthu@wsu.edu) Washington State University.
Described the proposed increase in fees for testing and therapy at Prosser. There is a new webpage www.healthyplants.wsu.edu associated with work at WSU.

Yannis Tzanetakis (itzaneta@uark.edu) University of Arkansas.
Provided information on viruses in Blackberries. There are 9 new viruses reported in Blackberries in the south east. These include Blackberry Virus E a flexivirus related to the Allexiviruses, also an emaravirus, a new Ilarvirus, a fovea-like virus, a picorna-like virus, and possibly an ophiovirus. With recent discoveries there are becoming too many viruses in small fruit for which to test: over 40 viruses in Rubus species, over 27 virus in strawberry, and 11 viruses in blueberry.

Georgios Vidalakis (vidalg@ucr.edu) UC Riverside, California.
Provided a description and update of the Citrus program at Riverside. His work has involved looking at viroids as transmissible small nuclear RNAs (TsnRNAs) that affect tree growth and morphology, work with citrus porosis virus, and using indirect approaches (detection of proteins secreted by the pathogen-Spiroplasma citri) rather than detection of the pathogen itself.

Shulu Zhang (shulu@agdia.com) Agdia Inc., Elkhart, Indiana
Gave a presentation on the use of recombinase polymerase amplification (RPA) for the detection of Plum pox virus.

The meeting adjourned at 5:00 PM on July 14th, 2011.

Minutes respectfully submitted by S.W. Scott, Clemson University

To view individual reports, go to the Homepage of WERA-20 and look in the Additional Documents section at: http://lgu.umd.edu/lgu_v2/homepages/home.cfm?trackID=13496

Collaborations built through WERA-20 continue to drive high profile grants funded under the Specialty Crops Research Initiative and the National Clean Plant Network. Research completed among collaborators in WERA-20 provided information on the incidence, distribution and epidemiology of viruses in fruit trees, small fruits, and grapevines. For example, an occurrence of Blueberry shock virus in Michigan was dealt with as a result of information developed by collaborators on the west coast. Information on the occurrence of viruses in the vineyards of the west coast allows growers to address problems associated with viruses and provides information on the sources of virus in the nursery industry. The problems with viruses in blackberry and blueberry (Blueberry necrotic spot virus Funky spot disease) in the southeastern US, where expertise is lacking, are addressed through collaborations with researchers in Arkansas and Oregon.

Coneva, E., J. Murphy, and R. Boozer, and N. Velasquez. 2010. Incidence and distribution of viruses in blackberry (Rubus sp.) in Alabama. International Journal of Fruit Science 10:87-95. Coneva, E., J. Murphy, R. Boozer, N. Velasquez. 2008. First report of Tobacco ringspot virus in Blackberry (Rubus sp.) in Alabama. Plant Disease 92:1708. Donglin Xu , Ray Mock , Gary Kinard , and Ruhui Li. 2011 Molecular analysis of the complete genomic sequences of four isolates of Gooseberry vein banding associated virus . Virus Genes 43:130-137. Eastwell KC, Villamor DV, McKinney CV, Druffel KL. 2010. Characterization of an isolate of Sowbane mosaic virus. Archives of Virology 155:2065-2067. Gibson, P.G. Reighard, G., Marini, D., and Scott, S.W. (2010). Effects associated with graft-transmissible agents found in peach variety 'Ta Tao 5'. Julius-Kuhn-Archiv. 427:284-288. James, D., Varga, A., Leippi, L., Godkin, S., and Masters, C. 2010. Sequence analysis of RNA 2 and RNA 3 of Lilac leaf chlorosis virus: a putative new member of the genus Ilarvirus. Archives of Virology. 155:993-998. James, D., Croft, H., Malinowski, T., and Reed, C. 2009. Production of antisera and evaluation of serology-based techniques for the detection of Blackcurrant reversion virus. 21st International Conference on Virus and Other Graft Transmissible Diseases of Fruit Crops. Neustadt, Germany, July 5 - 10, 2009. JKI Annual Report 148:21 (Abstr.). Karthikeyan, G., Alabi, O.J., and Naidu, R.A. 2011. Occurrence of Grapevine leafroll-associated virus 1 in two ornamental grapevine cultivars in Washington State. Plant Disease 95:613. Kim, B.T., Gibson, P.G. and Scott, S.W. (2010). Expression of the coat protein genes of PNRSV and PDV in the synergistic disease peach stunt. Julius-Kuhn-Archiv. 427:114-117. Li, Ruhui , Mock, Ray , Fuchs, Marc , Halbrendt, John , Howell, Bill and Liu, Zongrang (2011) Characterization of the partial RNA1 and RNA2 3' untranslated region of Tomato ringspot virus isolates from North America', Canadian Journal of Plant Pathology, 33:1, 94-99. Liming Lin, Ruhui Li, Ray Mock, Gary Kinard, 2011. Development of a polyprobe to detect six viroids of pome and stone fruit trees. Journal of Virological Methods 17: 91-97. Ma, X., Coneva, E., H. Fadamiro, J.F. Murphy, Charles Ray, and F. Dane. 2010. Seasonal occurrence and abundance of sharpshooter leafhoppers in Alabama Orchards and Vineyards. International Journal of Fruit Science 10:341-354. Martin, R.R., Zhou, J. and Tzanetakis, I.E. 2011. Blueberry latent virus: An amalgam of the Partitiviridae and the Totiviridae. Virus Research 155: 175-180. Melzer, MJ, Sether, DM, Borth, WB, Hu, JS. 2011. Characterization of a virus infecting Citrus volkameriana (Ten. & Pasq.) with citrus leprosis-like symptoms. Phytopathology (accepted for publication) Melzer, MJ, Nelson, SC, Hu, JS. 201X. Tristeza and blight diseases of citrus in Hawaii. CTAHR Cooperative Extension Services publication (in preparation) Melzer, M.J., Sether, D.M., Alvarez, A, Hu, J.S. 2011. Huanglongbing CTAHR Cooperative Extension Services publication Quito-Avila, D.F., Jelkmann, W., Tzanetakis, I.E., Keller, K. and Martin, R.R. 2011. Complete sequence and genetic characterization of Raspberry latent virus, a novel member of the family Reoviridae. Virus Research 155: 397-405. Sabanadzovic, S., Abou Ghanem-Sabanadzovic, N. and Tzanetakis, I.E. 2011. Blackberry virus E: an unusual flexivirus. Archives of Virology 156:1665-1669 Schilder, A. Blueberry Scorch Virus. Regional pest Alert, USDA NIFA Integrated Pest Management Program, the North Central IPM Center and the Land Grant Universities. Schilder, A. Blueberry Scock Virus. Regional pest Alert, USDA NIFA Integrated Pest Management Program, the North Central IPM Center and the Land Grant Universities. Tzanetakis, I.E., Martin, R.R., Scott, S.W. 2010 Genomic sequences of Blackberry chlorotic ringspot virus and Strawberry necrotic shock virus and the phylogeny of viruses in subgroup 1 of the genus Ilarvirus. Archives of Virology 155:557-561