TECHNOLOGY OF TESTING GENERATIVELY PROPAGATED PRUNUS-DOMESTICA L ROOTSTOCKS FOR PRUNE DWARF AND PRUNUS NECROTIC RINGSPOT VIRUSES

Comparative screenings using ELISA technique were performed to evaluate the incidence of prune dwarf (PDV) and Prunus necrotic ringspot (PNRV) viruses in seed, young two-leaf seedlings and elder field-grown seedlings of plum (Prunus domestica L.) varieties Damas noir, Gro-beta-e Grune Reneklode and Nancymirabelle. The rate of PDV/PNRV infestation in seeds was significantly greater than in seedlings grown up from the same seed lot. In seeds, two-leaf seedlings and elder field-grown seedlings, rates of infestation with PDV averaged 19.2, 2.0 and 0.4%, respectively. Infestation rates with PNRV were 6.4% in seeds, 0.8% in two-leaf seedlings and 0.5% in elder field-grown seedlings. The rates of infestation with PDV and PNRV in common were proved to be 0.6% for seeds and 0% for each of the two developmental stages of the seedlings.