菌株NJ-18是从油菜田土壤中分离筛选到的一株具有抗真菌活性的枯草芽胞杆菌。试验结果表明菌株NJ-18与油菜菌核病菌对峙培养能形成3.4 cm的抑菌圈;能抑制油菜菌核病菌菌丝生长发育;强烈影响菌丝生长量,NJ-18发酵滤液稀释62.5倍时对菌丝生长量抑制率高达96.7%,稀释1 000倍时抑制率16.7%。油菜离体叶片试验表明,NJ-18发酵液原液对菌核病的防治效果高达100%,原液稀释200倍后防效10%。大田试验结果表明,NJ-18发酵液稀释500倍对油菜菌核病的防治效果高达57.4%,明显高于用量为150 g a.i./hm2的醚菌酯48.1%的防治效果。采用浸根法研究NJ-18在油菜上的定殖动态表明,菌株NJ-18能够在油菜体内定殖,并能从油菜的根部向叶子扩散。 Strain NJ-18 is an antifungal bacillus subtilis isolated and screened from the soil of rapeseed field. The results showed that strain NJ-18 and S. sclerotiorum could inhibit the growth of mycelium of S. sclerotiorum at a 3.4 cm inhibition zone. The growth of mycelium was strongly affected. When NJ-18 fermentation filtrate was diluted by 62.5 folds The mycelial growth inhibition rate as high as 96.7%, diluted 1 000 times the inhibition rate of 16.7%. In vitro rapeseed leaves experiment showed that the control effect of NJ-18 fermentation broth on sclerotinia was as high as 100%, and the stock solution was 200% diluted with 10% control effect. The results of field trials showed that the control efficacy of NJ-18 diluted 500-fold on sclerotinia sclerotiorum was as high as 57.4%, which was significantly higher than that of 48.1% for the control of rubustril at the dosage of 150 g a.i./hm2. Studying the colonization dynamics of NJ-18 in Brassica napus by root immersion method showed that strain NJ-18 could colonize in rapeseed and diffuse from root to rapeseed.