SEED TRANSMISSION OF TURNIP YELLOW MOSAIC-VIRUS IN WINTER TURNIP AND WINTER OILSEED RAPES

This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYM V in a naturally infected winter turnip rape (Brassica napus var. silv estris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8 .3% seed transmission of the virus was found in seed of plants from th ree localities. The proportion of infected seeds produced by artificia lly infected plants of winter oilseed rape (Brassica napus ssp. oleife ra) and winter turnip rape cultivars was determined. The virus transmi ssion rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and f or the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in dire ct tests on bulk seed lots to estimate proportion of infected seed, bu t must be used on germinated seedlings.