VACCINE STRAIN OF TOMATO MOSAIC VIRUS OBTAINED AFTER SERIAL PASSAGES OF ATTENUATED STRAIN OF TOBACCO MOSAIC VIRUS IN TOLERANT TO TOBAMOVIRUSES TOMATO

An attenuated strain of tobacco mosaic virus (TMV) isolated from tobacco and symptopmless for tomato and pepper was put in fivefold passage in tolerant to tobamoviruses tomato. The changes in the strain population after the passages were studied by determination of the virion electrophoretic mobility, serological and biological properties of purified preparations of the obtained isolates. All performed experiments proved that as early as in the first passage TMV was replaced by a tomato mosaic virus (ToMV). After five serial passages the presence of virions causing mosaic in susceptible and/or tolerant tomato were not found. The study for vaccine properties of the new obtained isolate ToMV D52-V showed that it belonged to Pelham's group "1" since it was effective in tomato carrying Tm-1 gene. Its protective action did not give way to that of analogous vaccines applied in the practice and hence strain D52-V could be successfully used for protection of susceptible and tolerant tomato against pathogenic tobamovirus strains.