Exploration of Alternative Hosts for Grapevine Red Blotch -Associated Virus

Science Center, Bent Corridor

Grapevine red blotch-associated virus (GRBaV) of Vitis sp. is a putative new member of the family Geminiviridae. The complete sequence of the GRBaV genome was published in 2012 and the virus has since been detected in all major grape-growing regions of the United States, likely due to transmission via infected propagation material and grafting. GRBaV is also transmitted by the three cornered alfalfa treehopper (Spissistilus festinus Say). S. festinus is not a pest of grapevine, but can cause economic losses in fabaceous crops, including soybean, alfalfa, and peanut. Some fabaceous species are sown in vineyard row middles as cover crops. This warrants the evaluation of their potential to host GRBaV. A major objective of this project was to inoculate fourteen varieties of fabaceous plants with an infectious bitmer clone of GRBaV via Agrobacterium tumefaciens-mediated infection. After two and four weeks, petioles were collected and tested for GRBaV by reverse transcription polymerase chain reaction (RT-PCR) to verify virus infection. Any legume species that tests PCR positive for GRBaV will be further examined for its potential as a reservoir for S. festinus-mediated transmission. This research is important to better understand the epidemiology of GRBaV.