2株番茄早疫病拮抗菌的分离筛选与拮抗作用研究

Isolation and Screening for 2 Stains of Antagonistic Bacteria against Alternaria solani of Tomato and Study on Antagonistic Effect

【目的】从新疆昌吉、焉耆、喀什、乌苏、吉木萨尔五地多年种植番茄的农田土壤样品,进行拮抗菌的筛选,选取对番茄早疫病菌(Alternaria solani)有具有较强抑菌活性的菌株。【方法】采用平板分离培养法从加工番茄的根际土壤中分离拮抗菌,平板对峙培养实验进行初筛和复筛,根据培养特征、菌体形态及16S r DNA系统发育分析进行初步鉴定,显微观察法观察拮抗菌对病原菌菌丝生长的拮抗作用,盆栽法测定相对防效。【结果】共分离得到90株细菌菌株,初筛得到对番茄早疫病菌有明显拮抗作用的细菌,复筛选取2株抑制作用显著的细菌(J2-2、J2-4),并初步鉴定为芽孢杆菌属(Bacillus)的萎缩芽孢杆菌(Bacillus atrophaeus)和枯草芽孢杆菌(Bacillus subtilis)的近似种;显微镜下观察到2株拮抗菌的发酵液对番茄早疫病菌丝有明显的致畸作用;在盆栽试验中,拮抗菌发酵液对番茄早疫病菌的相对防效可达到35%以上。【结论】筛选到的2株拮抗菌对番茄早疫病菌表现出较好的拮抗作用,对番茄早期病害的生物防治具有一定的应用价值。

[Objective] Screening for bacteria against4以 eniaha so/anio tomato from rhizosphere of pro-cessing tomato.[Method] Isolating antagonistic bacteriafrom rhizosphere of processing tomatoby culture on me-dium plate, preliminary screening and second screening are carried on by paired culture, preliminary identifi-cation is based on morphological characteristic, phylogenetic analysis of 16S rDNA, antagonistic effect of fer-mentation broth against mycelium ofA. solani is observed under microscope, relative control effect of fermenta-tion brothof antagonistic bacteria is observed by pot incubation test .[Result] 90trains of antagonisticbacteria have been isolated,from them, 3 strainsofbacteriahave been screened by preliminary screening while 2 strains by second screening with obvious antagonistic effect （J2 - 2, J2 -4） , and then the two stains were prelimina-ry identified as allied species oiBacillus atrophaeus andBacillus subtilis, teratogenic effect of fermentation brothagainst pathogenic mycelium has been observed under microscope, the relative control effect of fermenta-tion broth has been determined above 35% in pot incubation test. [Conclusion]The result shows that the two isolates with significant antagonistic effect toA. solani could provide potential solution for biological control of early blighttomato.