摘要：本实验以防治棉花枯萎病为目的，从江苏南京江宁区采集的土壤中分离并筛选对棉花枯萎病菌具有拮抗作用的细菌菌株。通过平板对峙法、滤纸片法、三明治法、琼脂扩散法测定拮抗细菌的拮抗能力，比较各种方法的优缺点，从而筛选最佳的测定方法。实验结果表明，3株细菌yk1、yk2、yk3具有对棉花枯萎病菌的拮抗作用，平板对峙法为测定其抑菌活性的最佳方法。实验还测定拮抗细菌的粗提物抑菌活性，对拮抗能力最强的菌株yk1进行了培养基的优化。

关键词:棉花枯萎病；拮抗细菌筛选；拮抗能力测定

Abstract: The purpose of this experiment was to separate and screen the antifungal bacteria against Fusarium oxysporium f.sp. vasinfectum from the soil of Jiangsu Nanjing Jiangning district. Through the flat confrontation method, filter paper method, “sandwich” method, agar diffusion method to determine the antifungal ability of the bacteria, comparing the advantages and disadvantages of these methods, so as to select the best method for the determination. The results showed that three bacteria named yk1,yk2 and yk3 had the antifungal ability against Fusarium oxysporium f.sp. vasinfectum, flat confrontation method was the best. The experiment also determined the antifungal ability of the crude extract of the bacteria and optimizated medium for yk1 which had the best antifungal ability.

Key words: Fusarium oxysporium f.sp. vasinfectum, Screening of antifungal bacteria, Determination of antifungal ability