Abstract
The sizes and homology relationships among double-stranded RNA (dsRNA) molecules from American and European hypovirulent isolates of Endothia parasitica were compared. The number, size, and relative intensity of dsRNA bands in gels varied among isolates. The sizes of dsRNA segments from each isolate ranged from a molecular weight of 0.56 .times. 106 to 6.2 .times. 106. No single size of dsRNA molecule was common to all isolates. The dsRNA from isolate GH2 hybridized to dsRNA from all other Michigan isolates tested, with the exception of dsRNA from isolate RC1. RC1 dsRNA did not hybridize to dsRNA from any other Michigan isolates tested. Neither GH2 nor RC1 dsRNA shared homology with dsRNA from other states or from Europe.