拮抗细菌A2菌株的鉴定及其对小麦白粉病的防治效果

Identification of an Antagonistic Bacterium A2 and Its Control Effect on Blumeria graminis f.sp. Tritici

为适应现代无公害农业的发展,针对小麦白粉病的防治,从保护地土壤中分离得到一株生防细菌A2。通过形态学特征、生理生化特性的观察和测定,结合16S rDNA序列分析并构建系统发育树,对菌株A2进行了初步鉴定。同时,以清水为对照,测定了菌株A2对3432品种小麦白粉病的防治效果。结果显示该菌株主要特征是菌体杆状,内生芽孢、芽孢卵圆形,革兰氏染色阳性,好氧,接触酶反应、乙酰甲基甲醇实验为阳性,能利用柠檬酸盐;该菌株与亲缘关系较近菌株B.subtilis isolate G8的同源性达99%。结合以上两点,将菌株A2初步鉴定为枯草芽孢杆菌(B.subtilis)。防效实验显示菌株A2发酵液处理最好防治效果为72.22%;无菌滤液处理最好防治效果为29.24%,与对照相比均具有显著性差异(α=0.05)。表明,拮抗菌株A2菌体与代谢产物对小麦白粉病都具有较强的防治作用,为研制型、无毒、无公害生物农药提供了依据。

For adapting the development of free pollution agriculture and aiming at biological control of Blumeria graminis f.sp.Tritici,we isolated an antagonistic strain A2 that was identified as Bacillus subtilis from soil of protected farmland.The strain was identified based on morphological,physical characteristics and the homological analysis of 16S rDNA sequence.Meanwhile,testing the control efficacy of Blumeria graminis f.sp.Tritici with the treatment of spraying clear water as control.The results showed that： A2 strain was road-shaped bacteria and gram-positive,could produce bacterial endospores of oval,amylase,fluidity glutin,and showed the positive reaction in the litmus milk test.In pot plant experiments,A2 strain and its culture supernatant showed significant control efficacies against Blumeria graminis f.sp.Tritici,and the control efficacy of admixture of them was much better.The control efficacy of fermentation broth of A2 strain achieved 72.22%,when the control efficacy of culture supernatant of A2 strain was 29.24%.The conclusion was drawn that： it was feasible for A2 to be applied in biological control and could provide scientific basis for the production of new free pollution biopesticide.