Inhibition activity of biocontrol bacteria,strain JK-2,on Fusarium oxysporum

Fifty-eight strains of Bacillus spp.were isolated from the rhizospheric soils around watermelon,tomato and other plants at Yongtai,Fuqing,Minhou and 3 other counties in Fujian.Using multiple target pathogens inhibition test on 6 strains of Fusarium oxysporum Schl.,3 showed high inhibition activities.Among these strains of the biocontrol bacteria,Brevibacillus brevis JK-2,was most effective.Strain JK-2 displayed a broad-spectrum antagonistic activity to pathogenic fungi and bacteria,including Verticillium dahliae,Verticillium albo-atrum,Verticillium fungicola,Colletotrichum gloeosporioides,Monilia laxa and Ralstonia solanacearum.The antimicrobial compounds produced by JK-2 were stable to high temperature(i.e.,100℃)and insensitive to proteinase K.It had control efficacies to watermelon wilt at 83.60% and 78.96% in the field and pot culture tests,respectively.