BIOLOGICAL CHARACTERIZATION OF AN ITALIAN ISOLATE OF BARLEY YELLOW DWARF LUTEOVIRUS FROM BARLEY

An isolate of BYDV (BYDV-OC), from barley in Northwest Italy with typi cal symptoms of yellowing and dwarfing, was transmitted by Rhopalosiph um padi, Sitobion fragariae, S. avenae, Metopolophium festucae, R. mai dis and M. dirhodum, but not by Myzus persicae or Schizaphis graminum. It reacted in DAS-ELISA with monoclonal and polyclonal antisera to PA V, but not with antibodies to MAV, RPV and RMV. A polyclonal antiserum prepared to BYDV-OC did not react with MAV-like, RPV-like, or RMV-lik e isolates of BYDV in ELISA or in Western blots. The concentration of BYDV-OC in Avena byzantina plants decreased from weeks 1 to 10 after i noculation, but the total virus content per plant increased up to week s 7 to 8, following the increase of plant weight.