Detection of Two Strains of Grapevine Virus A. P. L. Monette, Research Scientist, Agriculture Canada, Plant Quarantine Station, 8801 East Saanich Road, Sidney, British Columbia, Canada, V8L 1H3. D. James, Research Scientist, Agriculture Canada, Plant Quarantine Station, 8801 East Saanich Road, Sidney, British Columbia, Canada, V8L 1H3. Plant Dis. 74:898-900. Accepted for publication 9 April 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0898.

Two isolates of grapevine virus A (GVA), mechanically transmitted from leafroll-affected grapevine cultivars to Nicotiana benthamiana and designated SA646 and SA36, were purified from in vitro node cultures of N. benthamiana and reinoculated into N. benthamiana seedlings. Symptom development differed reproducibly between the two isolates. At 3 wk postinoculation, the N. benthamiana inoculated with GVA isolate SA646 showed a systemic dwarfing with vein clearing of the tertiary and smaller veins, whereas those inoculated with isolate SA36 showed a systemic dwarfing with a pronounced interveinal chlorosis. The strains were not serologically distinguishable using either of two polyclonal antisera.