|AL RWAHNIH, MAHER - University Of California
|DAVE, ASHITA - US Department Of Agriculture (USDA)
|ANDERSON, MICHAEL - University Of California
|ROWHANI, ADIB - University Of California
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2013
Publication Date: 10/1/2013
Publication URL: http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-10-12-0253-R
Citation: Al Rwahnih, M., Dave, A., Anderson, M.M., Rowhani, A., Uyemoto, J.K., Sudarshana, M.R. 2013. Association of a DNA virus with grapevines affected by red blotch disease in northern California. Phytopathology. 103:1069-1076.
Technical Abstract: In Napa, CA, Cabernet Franc, Cabernet Sauvignon and Zinfandel grapevines in three separate vineyards exhibited foliar symptoms comprised of red blotches, marginal reddening and red veins, and reduced total soluble solids in harvested fruits. Foliar symptoms were initially diagnosed as leaf roll disease. However, RT-PCR assays for all known leafroll viruses were negative with an exception of Grapevine leafroll-associated virus 2 in Zinfandel. Metagenomic analysis of cDNA libraries obtained from dsRNA enriched nucleic acid preparations from bark scrapings of dormant canes on an Illumina platform, revealed virus sequences having a distant relationship with geminiviruses. Sequencing of products obtained by PCR assays using overlapping primers and rolling circle amplification confirmed the presence of a single circular genome of 3206 nucleotides, nearly identical to Grapevine Cabernet franc-associated virus recently reported from New York. Primers specific to the virus amplified a product of the expected size from DNA extracts obtained from petioles of diseased source vines. Chip bud inoculations from diseased sources successfully transmitted the virus to test plants as confirmed by PCR analysis. This is the first report of a DNA virus associated with grapevines showing red blotch disease symptoms in California and we hence propose the virus name: ‘Grapevine red blotch-associated virus’.