AGGRESSIVENESS OF GIBBERELLA-FUJIKUROI (FUSARIUM-MONILIFORME) ISOLATES TO GRAIN-SORGHUM UNDER GREENHOUSE CONDITIONS

Eleven strains of Gibberella fujikuroi mating population F and two strains of mating population A were tested for aggressiveness to grain sorghum plants grown under greenhouse conditions. All strains were tested against the cultivar Wheatland, and four strains were tested against Wheatland, SC599, B1778, and BKS45. No significant (P = 0.05) differences in aggressiveness were detected. Two cultivars previously described as resistant exhibited shorter main lesions than the susceptible cultivars, but this correlation was not significant when total lesion length was used to measure aggressiveness. Fusarium spp. could also be recovered from uninoculated control plants, but fewer than 10% of the isolates recovered from these plants were the same as the isolates used in this study, as measured by identity of vegetative compatibility groups.