番茄青枯病生防芽胞杆菌的筛选与鉴定

为了有效利用芽胞杆菌资源，本研究采用抑菌圈法从不同地理来源的芽胞杆菌中筛选出24个对青枯雷尔氏菌具有拮抗作用的菌株。其中，6个菌株对青枯雷尔氏菌的抑菌圈直径大于14.00 mm，菌株FJAT-11709的抑菌圈直径最大，为14.78 mm。盆栽试验比较了6个菌株对番茄青枯病的防治效果，结果表明，菌株FJAT-20261和FJAT-19700防效最好，分别达72.73%和67.77%。通过形态特征、生理生化测定及16S rRNA基因序列分析，菌株FJAT-20261和FJAT-19700分别被鉴定为耐寒短杆芽胞杆菌和特基拉芽胞杆菌。本文报道这2种芽胞杆菌对青枯雷尔氏菌具有拮抗作用，为青枯病的生物防治提供了新的菌株资源。

Selection and Identification of Biological Control Bacillus Strains agaist Plant Bacterial Wilt Disease

Bacillus are the most promising candidates of biocontrol agents. In this study, 24 Bacillus-like strains isolated from different geographical regions were exhibited antagonistic activity against Ralstonia solanacearum by the inhibition zone method. Among them, six strains appeared to have high antagonistic activities with the inhibition zone diameters (IZD) more than 14.00 mm. Moreover, the stain FJAT-11709 had the highest antagonistic activity with an IZD of 14.78 mm. Subsequently, the six Bacillus-like strains were further evaluated their control efficiencies against tomato bacterial wilt disease through the pot experiments. The strains FJAT-20261 and FJAT-19700 displayed excellent control efficiencies, reaching up to 72.73% and 67.77%, respectively. Finally, the strains FJAT-20261 and FJAT-19700 were separately identified as Brevibacterium frigoritolerans and B. tequilensis on the basis of the morphological features, physiological characteristics, and 16S rRNA gene sequence analysis. It is demonstrated that B. frigoritolerans and B. tequilensis could inhibit growth of R. solanacearum. This work provided new biocontrol agents against bacterial wilt disease.