Identification of a Strain of Antagonistic Bacterium against Fusarium oxysporum f.sp. cubense and Control Experiment of Bagged Seedlings in vitro

Five strains of Bacillus subtilis showing strong antagonistic effect against banana wilt disease were isolated from soils of rubber plantations by means of Flat Confrontation method.Morphologic characters and 16S rDNA sequences showed that S40 strain was Bacillus subtilis.Different concentrations of fermentation filtrates of S40 showed inhibitory effects on mycelia growth and spore germination of Fusarium oxysporum.Application of S40 fermentation filtrates significantly delayed the outbreak of banana wilt disease and time of death of bagged seedlings.The control effect of the three different applications were 71.2%、83.3% and 92.4% respectively.