枣炭疽病菌拮抗芽孢杆菌的筛选鉴定及其抑菌物质分析

Screening and Identification of Bacillus Antagonist Against Anthracnose of Jujube and Analysis of Its Antifungal Substances

从冬枣果实中分离芽孢杆菌,通过对峙培养法筛选对炭疽病菌有显著拮抗活性的菌株,利用冬枣果实检测拮抗菌对炭疽病的防治效果并对拮抗菌进行种属鉴定,采用抑菌圈法及液相色谱一质谱联用技术分别对拮抗菌合成抑菌物质进行抑菌活性检测和结构鉴定。获得1株对枣炭疽病菌有显著拮抗活性的芽孢杆菌Tj-19,经鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。Tj-19菌体及其发酵上清液对冬枣果实炭疽病的防治效果分别达到74.9%和75.8%,主要抑菌物质为伊枯草菌素A和伊枯草菌素B。

Bacillus strains isolated from jujube fruits with significant antagonistic activity against anthracnose was screened by confrontation culture method.The control effect of antagonistic bacteria against anthracnose was tested by in vivo experiment using winter jujube fruits.The activity and structure of the antifungal substance from the fermentation supernatant of the antagonistic bacterium were tested by inhibition zone method and liquid chromatography-mass spectrometry(LC-MS),respectively.Strain Tj-19 which exhibited significant antagonistic activity against jujube anthracnose was identified as Bacillus amyloliquefaciens based on the morphological observation,physiological and biochemical characteristics and 16 S rDNA and gyrB sequence analysis.The biocontrol effect of Tj-19 bacteria cell and its fermentation supernatant on anthracnose of winter jujube fruit reached 74.9%and 75.8%,respectively.The main antifungal substances from the fermentation broth of strain Tj-19 were Iturin A and Iturin B.