1株拮抗植物病原真菌的细菌筛选及其抑菌机理的初步研究

Screening of an Antagonistic Bacterial Strain against Plant Pathogenic Fungi and Its Antimicrobial Mechanism

从上海市郊农作物根际土壤中共分离纯化得到276株细菌,利用平板对峙法筛选出1株对多种植物病原真菌具有较强拮抗作用的菌株。经过形态学观察、生理生化特征以及16S rDNA的同源性分析,初步鉴定该菌株为桔黄假单胞菌(Pseudomonas aurantiaca),该菌株的16S rDNA序列已在GenBank中注册,登录号为GQ358919。通过显微镜观察,发现JD37菌株的主要抑菌机理是通过产生拮抗物质造成病原真菌菌丝体断裂、扭曲、畸形等异常生长现象。该菌产生的拮抗物质对酸、碱较为稳定,但对高温敏感。

276 bacterial strains isolated and purified from the soil samples collected from crops rhizosphere of in the suburban districts of Shanghai were obtained.JD37,an antagonistic bacterial strain among them screened with slab confrontation method,had fairly strong inhibition effect against many plant pathogenic fungi.It was initially identified as Pseudomonas aurantiaca based on observation of its morphologic characteristics,physiological and biochemical properties and phylogenetic analysis of 16S rDNA sequence registered at GenBank database with accession number GQ358919.It was found through microscope that the main inhibit mechanism of antagonist against pathogens was to lead mycelial rupture,distortion and abnormality of its growth.The antagonists were fairly stable to acids and bases stability,however,sensitive to high temperature.