CONTRIBUTION TO THE STUDY OF POTATO VIRUS ISOLATES

摘要

Four isolates of PVY (J-l, Br-4, D-6 and Le-18), originating from seed potato tubers were studied. The most important properties of the investigated isolates correspond to PVY. According to some characteristics investigated virus isolates differ fromeach other as well as from so far described PVY sirs. The properties in common with PVY were fillamentous virus particles of about 700 nm lenght, transmission by plant sap and by aphid vector Myzuspersicae in nonpersistant manner, DEP 10~(-2)-10~(-3)_,TIP 60-65°C, LIV 5-15 days, one type of antigen with MW about 34 kDa as well as serological activity, and symptoms caused on tobacco cv. Samsun (vein yellowing at the beginning, later on mottling and necrosis). Differences among studied isolates as wellas to known PVY sirs, were reactions of some test plants. Isolate Le-18 is infectious to Datura stramonium causing mild mottling, and to pepper causing large, necrotic spots on inoculated leaves, followed by small necrotic spots on new leaves and necrotic streaks on stem. Isolate D-6 is not infectious to D. stramonium nor to pepper, it causes chlorotic spots, netlike pattern and mild mosaic. Isolates Br-4 and J-l are neither infectious to D. stramonium nor to pepper. Br-4 is not infectious to Physalisfloridana. J-l as well as isolates D-6 and Le-18 infect P. floridana causing vein yellowing and mosaic. Br-4 isolate is specific according to the pathogenicity to tomato causing on it necrotic spots on inoculated leaves and chlorotic spots and dots on new leaves, like other studied isolates. Due to differences in pathogenicity shown to the mentioned test plants investigated PVY isolates are very specific and interesting for more detailed studies.