The isometric virus isolated from several lettuce plantations appeared to be dandelion yellow mosaic sequivirus. Despite of some differences it seemed to be closely related to Dutch Ls2 isolate. Identification was based on the host range, physico-chemical properties, electron microscopy and serology. The differences in virus susceptibility were found between 12 cultivars mechanically inoculated. None of approximately 1500 seedlings of 9 cultivars, derived from infected plants, was virus infected.
Investigations on the occurrence of Barley stripe mosaic virus (BSMV, Hordeivirus) in Poland were performer by testing seeds of 22 barley cultivars. BSMV was detected in seeds of winter barley cv. Tiffany and of spring barley cvs. Scarlett and Stratus. The virus presence was revealed by ELISA test and then confirmed by electron microscopy. Preliminary data on the rate of seed transmission of BSMV in cvs. Scarlett and Stratus are presented.