A DOUBLE-STRANDED-RNA MYCOVIRUS FROM THE PLANT-PATHOGENIC FUNGUS, FUSARIUM-SOLANI F SP ROBINIAE

Two kinds of double-stranded RNA (dsRNA), estimated to be 1.9 and 1.7 kb in size, were detected in the plant pathogenic fungus, Fusarium sol ani f. sp. robiniae. Isometric virus-like particles (VLPs), 30 nm in d iameter, were recovered from cell extracts as a discrete band when cen trifuged through a CsCl density gradient. The dsRNA molecules extracte d from VLP preparations were identical in electrophoretic mobility to the dsRNAs obtained directly from cells. SDS-PAGE analysis of the VLPs revealed a single polypeptide of 38 kDa. The dsRNAs were transmitted at a frequency of 85% through microconidia (the asexual cycle).