黄瓜疫病菌拮抗细菌的分离及鉴定

Isolation and Identification of Antagonistic Bacteria against Phytophthora melonis

[目的]筛选对黄瓜疫病有较好稳定防治能力的生防菌。[方法]采用系列稀释法和平板涂布法对黄瓜疫病菌拮抗细菌进行初步分离,进一步通过平板对峙法对其进行筛选,并通过形态学、生理生化特征、16S rDNA序列分析方法对拮抗效果较好的细菌进行了鉴定。[结果]共分离到黄瓜疫病病原菌的拮抗细菌56株,有4株细菌对黄瓜疫病病原菌显示出较强的拮抗效果,其中LY-38菌株对黄瓜疫病病原菌拮抗带宽为6.5 mm,抑菌率高达81.2%,通过鉴定可以确定该菌株为枯草芽孢杆菌(Bacillus subtilis)。[结论]为黄瓜疫病的田间生物防治提供了参考。

[ Objective ] The aim was to obtain good antagonistic bacteria against P. melonis. [ Method ] Some antagonistic bacteria against P. melonis were isolated from soil by using serial dilution method and spread-plate method, further screened on plate. Then efficient antagonistic bacteria against P. melonis were identified by using morphology, physiological and biochemical characteristics and 16S rDNA sequence analysis. [ Result ] Fifty-six bacteria were initially isolated by the serial dilutions and plate coating method and have an antagonistic effect on cucumber blight pathogen. Four of them were further identified by the plate confrontation method and showed strong antagonistic effect on cucumber blight pathogen. LY-38 showed the antagonism bandwidth of 6.2 mm on cucumber blight pathogen and the inhibition rate of 81.2%. The LY-38 strain was identified as Bacillus subtilis. [ Conclusion ] The research result provides reference for field biological control of P. melonis.