Double-stranded RNAs isolated from plant tissue infected with red clover necrotic mosaic virus correspond to genomic and subgenomic

Red clover necrotic mosaic dianthovirus (RCNMV) has a genome of two ssRNA species, RNA 1 (4-0 kb) and RNA 2 (1-4 kb). Double-stranded RNA was isolated from Phaseolus vulgaris plants infected separa-tely with five isolates of RCNMV from Czechoslova-kia, Sweden, Scotland and England. In each case three species of dsRNA, designated A, B and C in order of increasing mobility, were solved by gel electrophore-sis in non-denaturing conditions. The mobilities of dsRNA species A and B were similar for all the isolates, but the mobilities of the different species of dsRNA C showed some variation. Southern blotting followed by hybridization with cloned probes showed that dsRNA species A and B are related to RNA 1, whereas dsRNA C is related to RNA 2. In gel electrophoresis