解淀粉芽胞杆菌防治番茄果实灰霉病及其抑菌物质分析

通过对峙培养法筛选对灰葡萄孢菌有显著拮抗性的产芽胞细菌，利用番茄果实检测拮抗菌及其发酵上清液对灰霉病的防治效果，采用ESI-MS检测拮抗菌发酵上清液粗提取物中主要抑菌物质并利用PCR检测合成抑菌物质的相关基因，通过菌体菌落形态观察、生理生化试验、16S rDNA及gyrB分析对拮抗细菌进行种属鉴定。结果表明，分离筛选的拮抗菌fqhm-13及其发酵上清液对番茄果实灰霉病防治效果分别达到69.0%和78.1%。fqhm-13发酵上清液粗提取物中主要抑菌物质为脂肽抗生素C14 ~ C16的surfactin A和C15 ~ C17的iturin A。fqhm-13基因组中含有脂肽抗生素合成基因ituC、ituD、fenD和srfAB。fqhm-13菌株为解淀粉芽胞杆菌（Bacillus amyloliquefaciens）。该研究为利用芽胞杆菌及其代谢产物防治番茄果实灰霉病奠定了材料基础。

Biocontrol Ability of Bacillus amyloliquefaciens Against Gray Mold on Tomato Fruit

Gray mold caused by Botrytis cinerea has been found to be the main fungal disease of tomato fruit. The dual culture method was used to screen for Bacillus strains with significant antagonistic activity to B. cinerea. Further testing of control efficiency was completed by spraying the antagonistic bacterium and its fermentation supernatant on tomato fruits. ESI-MS was utilized to detect main antifungal substances in the antagonistic bacterium’s fermentation supernatant crude extract. Further analysis using PCR allowed for the detection of genes related to antimicrobial substances synthesis. The species of the antagonist bacterium was identified through its colony and cell morphology，physiological and biochemical tests，and 16S rDNA and gyrB analysis. The control effect of the screened antagonist fqhm-13 and its fermentation supernatant on gray mold of tomato fruit was identified to be 69.0% and 78.1%，respectively. The main antimicrobial substances in the qhm-13 fermentation supernatant crude extract include lipopeptide antibiotics of C14–C16 surfactin A and C15–C17 iturin A. PCR detection showed.that the genome of fqhm-13 contained genes related to antibiotic synthesis，such as ituC，ituD，fenD and srfAB. Through species identification techniques，strain fqhm-13 was identified as Bacillus amyloliquefaciens. This study laid the foundation for the use of B. amyloliquefaciens and its metabolites to prevent and control gray mold on tomato fruit.