番茄灰霉病拮抗细菌的筛选与X-75菌株鉴定

Screening of Antagonistic Bacteria Against Botrytis cinerea and Identification of Strain X-75

采用琼脂平板扩散法筛选对番茄灰霉菌具有拮抗作用的细菌,经过对200株分离自土壤的细菌菌株进行初筛、复筛后,得到了1株具有较高拮抗活性的菌株X-75。对该菌株进行形态观察和生理生化特征分析,初步将其鉴定为芽孢杆菌属(Bacillus sp.),将其16SrDNA序列与GenBank中已知标准菌株的16SrDNA序列进行比对,并用Neighbor-joining方法构建X-75菌株进化树,结果表明,X-75与标准菌株AB245422 Bacillus velezensis聚于同一分支,同源性最高,达99.93%;利用番茄离体叶片对X-75菌株的防效进行初步检测,结果表明X-75菌株对番茄灰霉病菌具有明显的拮抗作用。

In order to obtain antagonistic bacteria against Botrytis cinerea,about 200 strains of bacteria isolated from soil samples were screened with the agar plate diffusion method.After primary and secondary screening,the strain X-75 showed the most significant antagonistic activity.After the morphological observation and a series of physiological and biochemistry experiments,the bacterial strain X-75 was primarily identified as Bacillus sp.The similarity of the 16S rDNA sequences between X-75 strain and AB245422 Bacillus velezensis was 99.93%,so it was finally identified as the nearest genetic relationship with Bacillus velezensis.And the X-75 strain showed obvious antagonistic activity against Botrytis cinerea Pers on tomato leaves.