3株生防芽孢杆菌的筛选及对棉花枯萎病的防治研究

Screening of Three Antifungal Bacillus sp.Strains and the Pot Test to Control Seedling Disease Pathogens on Cotton

从植物根际土壤中筛选到3株对大豆根腐病、棉花枯萎病、小麦赤霉病等多种作物真菌病害有较强拮抗性的芽孢杆菌菌株Bacillus sp.920,Bacillus sp.930和Bacillus sp.932。用琼脂块法分别测定了它们对11种植物病原真菌的抗菌谱、发酵液的抑菌活性大小及其热稳定性,并对发酵液中的抑菌活性物质进行了初步提取。结果表明,920和932菌株为广谱性抗真菌菌株;930菌株仅表现出对稻瘟病菌具有较强的拮抗性。Bacillus sp.920发酵液中的抑菌活性物质可被酸沉淀,并具有较好的热稳定性。棉花盆栽试验结果表明,接种芽孢杆菌920菌剂可使棉花枯萎病引起的棉苗死亡率由15%降至3.7%,发芽率比对照提高了10%。

Three strains of Bacillus sp. 920,930 and 932 were isolated from the soil around plant roots which have stronger antagonism against Fusarium oxysporum, F. oxysporum f. vasinfectum, Gibberella zeae and many other pathogenic fungi. By the agar plate method, three strains were tested for antagonism against eleven species fungi. The antifungal activity of their culture filtrates were compared among the three strains, and the antifungal sustance of Bacillus sp. 920 has been extracted. The test indicated that the culture filtrates of Bacillus sp. 920 contained a theremostable antifungal compound and could be subsided. The pot test results on cotton showed that the dead ratio of seedling cotton was decreased to 3.7% from 15.0% by inoculating Bacillus sp. 920.