Current status of virus diseases in Washington State vineyards

Transcription

1 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 Phone: E mail: naidu@wsu.edu

2 Topics to be covered Introduction How many viruses in WA? A brief update on Foundation Block program Questions?

3 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!!!

4 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

5 Grapevine leafroll disease The most severe disease worldwide Accounts for about 60% of the total world losses of grape production due to viruses

6 Impact of GLD on grapes cv. Cabernet franc cv. Chardonnay Uneven ripening Unequal size Less compact Poor quality (less sugar & more acid)

7 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

8 White grape cultivar cv. Chardonnay Red grape cultivar cv. Cabernet franc

9 Grapevine leafroll disease Red grape cultivar cv. Merlot Downward rolling of leaves White grape cultivar cv. Chardonnay

10 Cabernet Sauvignon Merlot

11 Wide range of foliar symptoms in red-grape cultivars

12 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)

13 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

14 Rugose wood disease complex Rupestris stem pitting-associated virus (RSPaV) Grapevine virus A (GVA) Grapevine virus B (GVB) Grapevine virus D (GVD)

15 Grapevine fanleaf disease Grapevine Leaf deformation Yellow mosaic Healthy Fan-leaf Vein-banding (Source: Deborah Golino, UC-Davis)

16 Grapevine fanleaf disease Grapevine fanleaf virus Nematode vector Dagger nematode Xiphinema index (Source: Deborah Golino, UC-Davis)

17 Do we have these virus disease problems in WA?

18 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

19 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 Plant Disease 89:

20 Grapevine viruses in the PNW Nematode transmitted viruses were not found!!! Arabis mosaic virus Tomato ringspot virus Grapevine fanleaf virus Source: Martin et al Plant Disease 89:

21 How about other viruses?

22 Collection of samples Cabernet sauvignon Chardonnay

23 Sample processing

24 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

25 RT-PCR detection of grapevine viruses Mr GLRaVs RG 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

26 RT-PCR detection of grapevine viruses in mixed infections RT-PCR GLRaV-1 Mr GLRaV GLRaV Mr bp bp

27 RT-PCR detection of grapevine viruses Multiplex RT-PCR Mr Mr GLRaV-3 GRSPaV

28 % plants tested positive Documentation of different viruses in Washington State vineyards GLRaV GLRaV GLRaV-2-RG 47.9 GLRaV GLRaV-4 GLRaV-5 Leaf roll 0.0 GLRaV GLRaV GRSPaV 15.5 GVA 2.7 GVB Total # tested = 593 Total # positive = 363 Total # samples tested = 593 Total # samples positive = 363 (61%) GVD Rugose Wood GFLV None

29 Proportion of single and mixed virus infections in grapevine samples Four viruses 4% Single 56% Mixed Three viruses 21% 44% Two viruses 75%

30 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%

31 Occurrence of viruses in wine grape cultivars Cultivars Total # # viruses detected per vine samples tested None Red Cab. Sauv. 158 (8*) Merlot 105 (5) Syrah 57 (3) Lemberger 82 (5) White Chardonnay 81 (6) White Riesling 23 (2) * # vineyards

32 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 Chardonnay

33 Number of viruses detected in WA vineyards GLRaV-1 GLRaV-2 GLRaV-3 GRSPaV a summary GLRaV-1 GLRaV-2 GLRaV-3 GLRaV-4 GLRaV-5 GLRaV-9 GVA GVB GRSPaV GFLV

34 Take home message Many viruses are present with implications in the sustainability of wine grape industry

35 What can we do? Use virus-tested cuttings WSU-Industry partnership

36 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

37 Further information Virology Program Foundation Block Program Contact: Naidu Rayapati Gary Ballard Markus Keller

38 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

39 Thank You