A LONG AND WINDING ROAD... The Discovery of the Red Leaf Viruses, the Leafrolls and Red Blotch Deborah Golino UC Davis (+) ssRNA (-) ssRNA Tobamovirus Sesquiviridae Comoviridae Bromoviridae Tobravirus Tombusviridae Cucumovirus Bromovirus Dianthovirus Hordeivirus Enamovirus Rhabdoviridae Luteovirus Cytorhabdovirus Idaeovirus Ilarvirus Machlomovirus Nucleorhabdovirus Furovirus Marafivirus Potexvirus Necrovirus Alfamovirus Sobemovirus Capillovirus, Trichovirus Tymovirus Carlavirus Bunyaviridae Tospovirus Potyviridae Closterovirus Tenuivirus dsDNA ssDNA dsRNA Caulimovirus Geminiviridae Isometric Geminivirus Banana buchy top virus group Reoviridae Badnavirus Partitiviridae Phytoreovirus Subgroup l,ll Alphacryptovirus Fijivirus Betacryptovirus Oryzavirus Subgroup lll A Short History of the Redleaf Grapevine Virus Diseases* *With much thanks to Dr. Marc Fuchs at Cornell University Discovery of Fanleaf Disease . First description in France (Cazalis-Allut, 1841) . Implication of a pathogen similar to the contagium vivum fluidum (Baccarini, 1902) . Fanleaf degeneration contracted from disease vineyard soil (Petri, 1918) . Identification of Xiphinema index, the dagger nematode vector (Hewitt et al., 1958) . Identification and characterization of Grapevine fanleaf virus as the causal agent (Baldacci et al., 1960; Cadman et al., 1960; Vuittenez, 1960) . Koch’s postulates fulfilled (Hewitt et al., 1962) Andret-Link et al. J. Pathol. 86:183 (2004) Discovery of Leafroll Disease . Description of “rougeau” in France (Ravaz and Roos, 1905; Pacottet, 1906) and ”rossore” in Italy (Arcangeli, 1907) . Graft-transmission (Scheu, 1935) . Association of a virus (Namba et al., 1979) . Serologically distinct viruses associated with the disease (Gugerli et al., 1984; Rosciglione and Gugerli, 1986) . Mealybug transmission (Rosciglione and Gugerli, 1987) . Koch’s postulates have yet to be fulfilled Maree et al. Frontiers in Microbiology 4:82 (2013) Discovery of Red Blotch Disease . First description in Napa Valley (Calvi, 2008) . A new DNA virus sequence (Krenz et al., 2012) . Diagnostic tools made available (Krenz et al., 2012; Al Rwahnih et al., 2012) . High correlation between virus presence and diseased vines (Al Rwahnih et al. 2013) . Graft transmissibility (Al Rwahnih et al. 2013) . Koch’s postulates have been fulfilled (Fuchs et al. 2014) Red Blotch: Challenges and opportunities Fanleaf First description 1841 Graft transmission 1962 Virus recognition 1960 Vector transmission 1958 Diagnostic assays 1960 Koch’s postulates 1962 Red Blotch: Challenges and opportunities Fanleaf Leafroll First description 1841 1905 Graft transmission 1962 1935 Virus recognition 1960 1979 Vector transmission 1958 1984 Diagnostic assays 1960 1984 Koch’s postulates 1962 n/a Red Blotch: Challenges and opportunities Fanleaf Leafroll Red blotch First description 1841 1905 2008 Graft transmission 1962 1935 2012 Virus recognition 1960 1979 2012 Vector transmission 1958 1984 2013 Diagnostic assays 1960 1984 2012 Koch’s postulates 1962 n/a 2013 FPS Target Grapevine Diseases Grapevine Degeneration Fanleaf Grapevine Decline Tomato Ringspot Virus Leafroll Rugose Wood Complex Kober Stem Grooving Corky Bark LN33 Stem Grooving Rupestris Stem Pitting Fleck Minor Viruses Leafroll Virus Early Leafroll History in California . Virus first hypothesized by Olmo as cause of ‘White Emperor Disease (Olmo and Rizzi, 1943) . Graft-transmissibility of WED demonstrated (Harmon and Snyder, 1946) . 1948, Olmo release ‘Ruby Cabernet’ found to be infected with Leafroll virus due to contaminated rootstock (Olmo 1975) . Hewitt writes W&V article urging Grape Certification Program (Hewitt 1949) . 1950, University and USDA researcher begin meeting with industry and planning a grape clean plant program . July 1952, the California Grape Certication Associate is formed . 1956, CDFA created the California Grapevine Registration and Certification Program Proposed new taxonomy for the leafroll viruses Genus Virus Acronym Closterovirus Grapevine leafroll associated virus 2 GLRaV-2 Ampelovirus Grapevine leafroll associated virus 1 GLRaV-1 Subgroup I Grapevine leafroll associated virus 3 GLRaV-3 Grapevine leafroll associated virus 4 GLRaV-4 Grapevine leafroll associated virus 4 strain 5 GLRaV-5 Grapevine leafroll associated virus 4 strain 6 GLRaV-6 Ampelovirus Grapevine leafroll associated virus 4 strain 9 GLRaV-9 Subgroup II Grapevine leafroll associated virus 4 strain Car. GLRaV-Car Grapevine leafroll associated virus 4 strain Pr GLRaV-Pr Grapevine leafroll associated virus 4 strain De GLRaV-De Velarivirus Grapevine leafroll associated virus 7 GLRaV-7 Closteroviridae family insect vector Velarivirus Unknown ?? Crinivirus Whiteflies Closterovirus Aphids Ampelovirus Mealybugs, soft scale, & sacle incest Leafroll Virus Effects Lider, L.A., A.C. Goheen, N.L. Ferrari. 1975. A comparison between healthy and leafroll- affected grapevine planting stocks. Am J. Enol Vit. 26:144-147. cv. Burger/ Dogridge Percent Year Parameter H LR-infected Change difference 1971 Yield (kg/vine) 16.5 12.5 -4 -24% Pruning weight 1.87 1.5 -0.37 -20% (kg/vine) Brix 19.6 16.8 -2.8 -14% TA 0.65 0.79 0.14 21% 1972 Yield (kg/vine) 23.2 19.8 -3.4 -15% Pruning weight 1.42 0.97 -0.45 -32% (kg/vine) Brix 16.3 13.9 -2.4 -15% TA 0.67 0.79 0.12 18% Walter and Legin, 1986. Connaissances actuelles sur les viroses de l’enroulement de la Vigne. Le Vigneron champenois, 9,436-446. Percent Clone Parameter Not inoculated LR-inoculated Difference difference Chardonnay 1 Yield (kg/vine) 1.49 0.85 -0.64 -43% Probable alcohol 10.1 8.2 -1.9 -19% content Chardonnay 3 Yield (kg/vine) 1.6 0.8 -0.8 -50% Probable alcohol 11 9.5 -1.5 -14% content Pinot noir 3 Yield (kg/vine) 1.26 0.49 -0.77 -61% Probable alcohol 9.6 8.6 -1 -10% content Pinot noir 98 Yield (kg/vine) 0.57 0.36 -0.21 -37% Probable alcohol 9.5 9.2 -0.3 -3% content Borgo, M. 1991. Influence of grapevine leafroll virus on some production parameters. Riv. Vitic. Enol 2:21-30. Mean of 3 years data; 5BB, 420A; LR- infected = LR-3, KSG, RSP, Vein necrosis Percent Variety Parameter Healthy LR-infected Difference difference Merlot Yield (kg/vine) 12.85 9.77 -3.08 -24% Brix 18.5 17.4 -1.1 -6% TA, g/l 6.76 6.97 0.21 +3% Cabernet Yield (kg/vine) 6.8 5.6 -1.2 -18% franc Brix 19.2 18.1 -1.2 -18% TA, g/l 5.27 5.78 0.51 +10% Cabernet Yield (kg/vine) 8.4 8.7 0.3 +4% Sauvignon Brix 19.3 18.2 -1.1 -6% TA, g/l 8.69 9.79 1.1 +13% Association of a Circular DNA Virus in Grapevines Affected by Red Blotch Disease in California M. Al Rwahnih1, A. Dave1,2, M. Anderson3, J. K. Uyemoto2 and M.R. Sudarshana1,2 1Dept. of Plant Pathology, 2USDA-ARS, 3Dept. of Viticulture and Enology, University of California, Davis, CA 95616, USA Zinfandel 1A on AXR, Fall 2011 Pinot noir Vitis vinifera cv. Cabernet franc Leafroll Red blotch Distribution of GRBaV . Wine grapes . Red . White . Table grapes . Raisin grapes . Rootstocks Distribution of GRBaV-infected vines Red Blotch: What Do We Know? . Red blotch is a recently recognized disease . Fruit ripening of diseased vines can be delayed in some vineyards . Brix can be substantially reduced . GRBaV, a newly discovered DNA virus, is associated with symptomatic grapevines . GRBaV is the causal agent of red blotch . Microshoot tip culture is not efficient at curing Red Blotch: What Do We Know? . GRBaV is graft-transmissible . Increased incidence of GRBaV in some vineyards over time . Virginia creeper leafhopper (Erythroneura ziczac) may be able to transmit GRBaV from grapevine to grapevine in the greenhouse . Symptoms can be misleading. Test, don’t guess! A PCR assay is available for diagnosis . Two distinct genetic variants of GRBaV Red Blotch: What Don’t We Know? 1. Ecology • Vector(s) • Transmission from grapevine to grapevine in vineyards 2. Detection • Maximize Sampling Efficiency 3. Interaction of GRBaV and other viruses • Synergistic/antagonistic/commensalistic relationships 4. Effect of GRBaV on vine health • Comparative performance evaluation • Tolerant cultivars/ rootstocks 5. Management • Clean stocks Foundation Plant Services UC Davis http://fps.ucdavis.edu Foundation Plant Services: . Produces, tests, maintains and distributes elite disease- tested plant propagation material . Provides plant importation and quarantine services, virus testing and elimination . Coordinates release of UC patented horticultural varieties . Links researchers, nurseries, and producers College of Agricultural & Environmental Sciences Pathogen Elimination Meristem shoot tip culture 10.0 mm Cut to < 0.5 mm 7 months Process Description: Grapevine Importation through Foundation Plant Services, UC Davis (Simplified) Document # FPS2012-01 © UC Regents S. Sim Revised March 6, 2012 YEAR 0 YEAR 1 YEAR 2 YEAR 3 YEAR 4 YEAR 5 YEAR 6 YEAR 7 YEAR 8 YEAR 9 Customer submits Service Request Form to FPS and identifies supplier. Supplier collects wood ships it to APHIS, Beltsville, Field Index MD Graft onto indicators: Cabernet franc Kober 5BB LN-33 APHIS inspects forwards St. George Read leaf Read trunk Read leaf shipment to FPS symptoms symptoms symptoms on St. on St. on George, George, LN- Cabernet Spring 33, and 5BB, franc Summer Fall Mist Mist Propagated Propagated Yolo county inspects Plants Plants Qualifies for shipment when opened. Available Available California FPS assigns Accession Provisional Provisional Registered number and Plant ID status status Foundation Stock numbers. Index buds Separate Propagate Growing Plant in Professional California Make 8 plants 4 plants in large pots Foundation Identification Registered