Abstract
Twenty-three isolates of barley yellow mosaic virus (BaYMV) collected from various sites in Japan were classified into six strains, I-1, I-2, I-3, II-1, II-2 and III, on the basis of pathogenicity to differential barley cultivars. Strain III was notable due to its pathogenicity to a newly developed resistant cultivar Misato Golden. These strains had similar particle-length distribution and were serologically identical. No distinct difference was observed among the strains in the MWs of RNAs and coat proteins, and the peptide patterns after limited proteolysis of coat proteins. These strains were distributed unevenly on a countrywide scale, and their occurrences were closely related to the types of barley cultivated. Strain M from West Germany had no serological relationship with any of Japanese strains, and differed from Japanese ones in its pathogenicity, MWs of RNAs and coat protein, and the peptide pattern after limited proteolysis. Strain M should be excluded from BaYMV.
