生防细菌L5生防相关因子的初步分析及其种类鉴定

Characterization and identification of a biocontrol bacterial strain L5

从扬州郊区土壤中分离到细菌菌株L5,该菌株抑菌谱广,对多种病原真菌都有明显的拮抗能力,离体叶片生物测定结果表明菌株L5对番茄灰霉病防效达72%。对该菌株的生防相关性状进行分析,结果表明菌株L5可产生硝吡咯菌素(Pyrrolnitrin)和嗜铁素等抗菌物质。经过16S rDNA序列、16S-23S rDNA间区序列同源性分析和生理生化性状的测定,将该菌株鉴定为气味沙雷氏菌(Serratia odorifera)。细菌菌株L5包含2个16S-23S rDNA的间区(IGSs),其中IGS1内含tRNAGlu基因,间区类型属于IGSG;IGS2内含tRNAIle和tRNAAla基因,间区类型属于IGSIA。

Bacterial strain L5 was isolated from soil in Yangzhou and showed inhibitory effect to many pathogenic fungi in dual-culture tests.This strain produced pyrrolnitrin and siderphore,and showed 72% efficiency to control grey mould caused by Botrytis cinerea on detached tomato leaves.The strain L5 was identified as Serratia odorifera based on sequence analysis of 16S rDNA and 16S-23S rDNA intergenic spacers（IGS）,physiological and biochemical characterization.The analysis of IGS sequence found two different types of IGS in strain L5.One included the tRNAGlu,and the other contained a cluster of tRNAIle and tRNAAla.