Location: Crops Pathology and Genetics ResearchTitle: Implicated vectors and spread of grapevine red blotch-associated virus in Oregon vineyards
|DALTON, DANIEL - Oregon State University
|WALTON, VAUGHN - Oregon State University
|HILTON, RICHARD - Oregon State University
Submitted to: Oregon Wine Research Institute
Publication Type: Abstract Only
Publication Acceptance Date: 4/6/2017
Publication Date: 4/6/2017
Citation: Dalton, D.T., Walton, V.M., Hilton, R.J., Sudarshana, M.R. 2017. Implicated vectors and spread of grapevine red blotch-associated virus in Oregon vineyards. Oregon Wine Research Institute Grape Day, April 6, 2017, Corvallis, Oregon.
Technical Abstract: Grapevine viruses have detrimental consequences for wine grape production, as is known for Grapevine leafroll -associated viruses (GLRaVs) and Grapevine red blotch -associated virus (GRBaV). From 2013-2016, vineyards in three wine grape production regions of Oregon were surveyed for the presence of GRBaV. Leaf tissues in study vineyards were collected and assayed using qPCR for GRBaV. Results were assessed to determine the rate of spread of GRBaV and to compare infection patterns with those of GLRaV-3. Virus -positive grapevines were subjected to spatial analysis to identify hotspots of virus infection, spatial distribution and patterns of spread within vineyard blocks. The findings indicate that GRBaV is present in the Willamette Valley and in Southern Oregon, and the spatial mapping strongly suggest that the virus is spread by insect vectors. Previous studies indicate that GRBaV is vectored by a membracid insect, Spissistilus festinus. In Fall 2016, leaf girdling and treehopper insects were observed in some study sites. The patterns of insect feeding damage were plotted and spatially analyzed in order to indicate the areas that have high levels of feeding symptoms. The patterns in all studied sites indicated significantly higher levels of feeding symptoms along the edges of the vineyard blocks. The membracid treehopper species Tortistilus albidosparsus and T. wickhami were collected in both regions in Oregon. We initiated greenhouse bioassays on these two species to determine whether they could vector GRBaV. The greenhouse studies are ongoing, and we will also determine the virus status of vines found in 2016 to have treehopper feeding damage.