CHARACTERIZATION OF DOUBLE-STRANDED-RNA FROM TILLETIA-INDICA

Double-stranded RNA was identified in six isolates of Tilletia indica, the causal agent of Karnal bunt disease of wheat. Double-stranded RNA s ranged from 2.8 to 12.3 kbp in size, similar to sizes reported for d ouble-stranded RNAs from other plant pathogenic fungi. The six isolate s revealed diverse double-stranded RNA banding patterns; however, iden tical patterns were found for two isolates (one from India, one from M exico). A random-primed cDNA probe generated from the high molecular w eight double-stranded RNA segment of isolate PV-18 hybridized only to double-stranded RNA of isolate PV-18 and not to double-stranded RNA of the other five isolates, indicating a high degree of sequence specifi city within the double-stranded RNA from at least one of the isolates tested. This is the first report of double-stranded RNA occurring in a ny species of Tilletia.