Screening of antifungal activities of Bacillus thuringiensis strains for the development of biocontrol agents of plant diseases

An attempt was made to screen antifungal activities of Bacillus thuringiensis strains on various plant pathogens, Botryosphaeria dothidea, Diaporthe actinidiae, Botrytis cinerea, Glomerella cingulata, Colletorichum cocodes, Sclerotinia scierotiorum, Alternaria alternata, Helicobuidium mompa, Bipolaris coicis, Fusarium graminearum and Rhizoctosnia solani. Ten and forty-five strains of B. thuringiensis were isolated from animal feces in Korea and Japan, respectively. Inhibitory effects of the strains on the mycelial growth of the pathogens were examined on the mixed media of potato dextrose agar and nutrient agar. Approximately half of the strains inhibited the mycelial growth of one or more pathogens. Most of the pathogens were inhibited by any of the strains but Fusarium graminearum and Rhizoctonia solani were not inhibited at all. This is the first report that B. thuringiensis shows a potent antifungal activity on plant pathogens in Korea.