Current status of virus diseases in Washington State vineyards Naidu A. Rayapati Department of Plant Pathology Washington State University Irrigated Agriculture Research & Extension Center Prosser, WA 99350 Phone: 509-786-9215 E mail: naidu@wsu.edu
Topics to be covered Introduction How many viruses in WA? A brief update on Foundation Block program Questions?
Grapevine is susceptible to many viruses About 60 viruses reported worldwide more than in any other perennial fruit crop! Some spread by vectors aerial (insect)- and soil (nematode)- born All viruses spread through vegetative cuttings suitcase viruses!!!
Virus diseases of the grapevine Disease Geographical distribution I. Major Leafroll complex Rugose wood complex Grapevine degeneration (fanleaf) II. Minor (partial list) Grapevine fleck Yellow mottle Line pattern Yellow dwarf Stunt Worldwide Worldwide Worldwide Worldwide Central & Eastern Europe Hungary Taiwan Japan
Grapevine leafroll disease The most severe disease worldwide Accounts for about 60% of the total world losses of grape production due to viruses
Impact of GLD on grapes cv. Cabernet franc cv. Chardonnay Uneven ripening Unequal size Less compact Poor quality (less sugar & more acid)
Grapevine leafroll - a complex disease GLRaV-1 GLRaV-2 GLRaV-3 GLRaV-4 GLRaV-5 GLRaV-6 GLRaV-7 GLRaV-8 GLRaV-9 More??? Grapevine leafroll-associated viruses (GLRaVs) One of the largest and most complex viruses known to infect plants
White grape cultivar cv. Chardonnay Red grape cultivar cv. Cabernet franc
Grapevine leafroll disease Red grape cultivar cv. Merlot Downward rolling of leaves White grape cultivar cv. Chardonnay
Cabernet Sauvignon Merlot
Wide range of foliar symptoms in red-grape cultivars
Rugose wood disease complex Rupestris stem pitting LN33 stem grooving (cv.. St. George) (cv.. LN 33) Infected Infected Healthy Healthy Kober stem grooving (cv. Kober 5BB) Infected Corky bark cv.. St. George & LN 33) Healthy (Source: Deborah Golino, UC-Davis)
Rugose wood disease complex Symptoms on woody trunk expressed when grafted onto American rootstocks Symptomless infection in own-rooted cultivars no effect on growth and yield? May cause synergistic effects in mixed infections with other viruses
Rugose wood disease complex Rupestris stem pitting-associated virus (RSPaV) Grapevine virus A (GVA) Grapevine virus B (GVB) Grapevine virus D (GVD)
Grapevine fanleaf disease Grapevine Leaf deformation Yellow mosaic Healthy Fan-leaf Vein-banding (Source: Deborah Golino, UC-Davis)
Grapevine fanleaf disease Grapevine fanleaf virus Nematode vector Dagger nematode Xiphinema index (Source: Deborah Golino, UC-Davis)
Do we have these virus disease problems in WA?
Grapevine viruses in WA vineyards Late 1990 s Concern that the incidence of grapevine leafroll disease was increasing Early 2000 The Washington Wine Advisory Board Funded a project to: - documentation of viruses in the PNW - set the direction of virus control programs
Grapevine viruses in WA Survey conducted during 2000 season in WA Grapevine leafroll disease Grapevine leafroll-associated viruses-1, -2, -3 Rugose wood complex Rupestris stem pitting-associated virus Source: Martin, et al. 2005. Plant Disease 89: 763-766
Grapevine viruses in the PNW Nematode transmitted viruses were not found!!! Arabis mosaic virus Tomato ringspot virus Grapevine fanleaf virus Source: Martin et al. 2005. Plant Disease 89: 763-766
How about other viruses?
Collection of samples Cabernet sauvignon Chardonnay
Sample processing 1 2 3 4 5 6 7 8 9
List of viruses Leaf roll RW complex Fan leaf GLRaV-1 GLRaV-2 GLRaV-2-RG GLRaV-3 GLRaV-4 GLRaV-5 GLRaV-7 GLRaV-9 GRSPaV GVA GVB GVD GFLV Technique: RT-PCR
RT-PCR detection of grapevine viruses Mr GLRaVs - 1-2 - RG - 3-4 - 5-9 + - + - + - + - + - + - + - + - + - + - + - GRSPaV GVA GVB GFLV Mr 500 bp 300 bp 100 bp GLRaV = Grapevine leafroll-associated virus RG = Red globe strain of GLRaV-2 GRSPaV = Grapevine rupestris stem pitting-associated virus GVA= Grapevine virus A GVB= Grapevine virus B + = virus-infected, - = healthy, Mr =100bp Marker
RT-PCR detection of grapevine viruses in mixed infections RT-PCR GLRaV-1 Mr 1 2 3 4 5 6 7 8 9 10 11 12 13 14 + - GLRaV-2 1 2 3 4 5 6 7 8 9 1011121314 + - GLRaV-3 1 2 3 4 5 6 7 8 9 10 11121314 + - Mr bp 1000 500 bp 1000 500
RT-PCR detection of grapevine viruses Multiplex RT-PCR Mr 1 2 3 4 5 6 7 8 Mr GLRaV-3 GRSPaV
% plants tested positive 60.0 50.0 40.0 30.0 20.0 10.0 0.0 Documentation of different viruses in Washington State vineyards 2006-07 3.4 GLRaV-1 8.3 GLRaV-2 0.7 GLRaV-2-RG 47.9 GLRaV-3 4.4 2.4 GLRaV-4 GLRaV-5 Leaf roll 0.0 GLRaV-7 2.9 GLRaV-9 7.9 GRSPaV 15.5 GVA 2.7 GVB Total # tested = 593 Total # positive = 363 Total # samples tested = 593 Total # samples positive = 363 (61%) 0.0 0.0 GVD Rugose Wood GFLV 38.79 None
Proportion of single and mixed virus infections in grapevine samples 2006-07 Four viruses 4% Single 56% Mixed Three viruses 21% 44% Two viruses 75%
Frequency of single and mixed infections of GLRaVs in grapevine samples Three GLRaVs 3,4,5 1% 2,3,9 1% 2,4,5 2% 2,3,4 11% 1,2,4 1% 1,3,4 3% Four GLRaVs 1,2,3,9 1% 2,3,4,9 1% 2,3,4,5 1% Two GLRaVs 1,5 1% 3,9 2% 2,4 3% 1,3 4% 3,4 7% 2,3 20% Single GLRaV 1 1% 2 10% 3 28% 4 3% 5 0% 9 3%
Occurrence of viruses in wine grape cultivars Cultivars Total # # viruses detected per vine samples tested None 1 2 3 4 Red Cab. Sauv. 158 (8*) 60 53 19 23 3 Merlot 105 (5) 67 25 8 5 0 Syrah 57 (3) 30 16 3 0 0 Lemberger 82 (5) 13 23 46 0 0 White Chardonnay 81 (6) 16 17 26 16 4 White Riesling 23 (2) 3 13 7 0 0 * # vineyards
Fanleaf virus detected for the first time in Washington State M (+) (-) CH 8-11 CH 9-9 CH 9-10 CH 9-11 CH 9-12 CH 9-13 CH 10-11 Chardonnay
Number of viruses detected in WA vineyards GLRaV-1 GLRaV-2 GLRaV-3 GRSPaV a summary 4 10 2000 2005-07 GLRaV-1 GLRaV-2 GLRaV-3 GLRaV-4 GLRaV-5 GLRaV-9 GVA GVB GRSPaV GFLV
Take home message Many viruses are present with implications in the sustainability of wine grape industry
What can we do? Use virus-tested cuttings WSU-Industry partnership
Pacific NorthWest Grape Foundation Service IAREC, Prosser Grapevine selections Tests positive Propagation & Testing Pathogen elimination Tissue culture Heat therapy Tests negative Retesting Foundation Block Isolated area Inspected annually Re-tested periodically ID correct Registered Foundation Grapevines Registered & Certified Nursery Grower Increase Block Inspected annually Re-tested periodically
Further information Virology Program http://winegrapes.wsu.edu/virology/ Foundation Block Program http://nwgfs.wsu.edu/ Contact: Naidu Rayapati Gary Ballard Markus Keller
Acknowledgements Lab members Dr. Gandhi Karthikeyan (Current) Dr. Tefera Mekuria (Current) Mr. Olufemi Alabi (Current) Mr. Sridhar Jarugula (Current) Dr. Marilyn J. Soule (Past) Dr. P. Rajakaruna (Past) Financial support from: Washington Wine Commission WSDA-Nursery Assessment Funds Washington State Commission on Pesticide Registration USDA-Northwest Center for Small Fruits Research WSU-New Faculty Seed Grant WSU Extension & ARC-CAHNRS
Thank You