Abstract
Fifty-eight strains of Gibberella fujikuroi were isolated from Bakanae-diseased seedlings of rice, and examined both for the susceptibility to benomyl fungicide and for the producibility of f umonisin mycotoxin. Among these strains, 46 strains (79%) were resistant to benomyl (MIC, >100 μg/g), and 57 strains showed the pathogenicity to rice seedlings, and all strains produced gibberellin Aa in liquid culture. Fumonisin was produced by 8 strains (14%): 23∼860 μg/g (mean, 380 μg/g) and B2 1∼43 μg/g (mean, 23 μg/g) in corn culture. The fumonisin producibility of these strains was also found in polished-rice culture, but the f umonisin concentrations in rice culture were lower than those in corn culture. Six strains of these producers were resistant to the fungicide. The incidence of fumonisin producers in G. fujikuroi associated with Bakanae disease and their producibilities of the mycotoxin were apparently low as compared with those of Fusarium moniliforme and F. proliferatum isolated from other substrates such as corn.
