N+离子注入枯草芽孢杆菌选育小麦全蚀病菌高效拮抗菌

为了进一步提高枯草芽孢杆菌(Bacillus subtilis)AZ菌株的拮抗性能,获得生防效果更好的菌株,利用低能N+离子束注入枯草芽孢杆菌AZ菌株进行诱变,并通过平板对峙培养等方法对诱变处理后的菌株进行筛选.结果获得AZ20-14、AZ40-13和AZ60-10三株对小麦全蚀病菌具有较强拮抗作用的正突变菌株.对峙培养结果表明,AZ20-14、AZ40-13和AZ60-10对小麦全蚀病菌菌丝生长的抑制效果均高于AZ菌株,菌丝生长抑制率分别为79.11％、71.71％和72.74％.经传代实验证明,AZ20-14、AZ40-13和AZ60-10的遗传性较为稳定.通过室内盆栽试验的方法研究了3个诱变菌株对小麦全蚀病菌的防治效果.结果显示,小麦种子经枯草芽孢杆菌AZ、AZ20-14、AZ40-13和AZ60-10的菌液浸种处理后,对小麦全蚀病防治效果依次为49.76％、58.52％、31.19％和51.66％.综合分析认为,经低能N+离子束注入后筛选获得的AZ20-14菌株不仅对小麦全蚀病菌的菌丝生长具有较好的抑制作用,而且能降低全蚀病的发病程度扣促进麦苗的生长.

Screening Nitrogen Implantated Bacillus subtillis Strains High-efficiently Antagonized to Gaeumannomyces graminis

In order to improve the antagonistic ability of Bacillus subtilis AZ and search for high-efficient mutant strains,Bacillus subtilis AZ strain was induced by low energy N⁺ ion beam implantation,and the mutation strains were screened by dual culture test and other methods. The results indicated that 3 strains of AZ20-14,AZ40-13 and AZ60-10 were higher-efficiently antagonized to Gaeumannomyces graminis var. tritici among the mutation strains. Dual culture test showed that the inhibitory effects of AZ20-14,AZ40-13 and AZ60-10 against the mycelial growth of G.graminis were higher than AZ strain,with inhibition rate of 79.11%,71.71% and 72.74%,respectively. Pass-generation test indicated that the heredity character of the three strains were stable. The control effects of the three strains on wheat take-all were tested by pot experiment with the wheat seeds soaked by the strains' suspension. The results revealed that the control effects of AZ,AZ20-14,AZ40-13 and AZ60-10 were 49.76%,58.52%,31.19% and 51.66%,respectively. All above results indicated that the strain AZ20-14,which was induced by low energy N⁺ ion beam implantation,could effectively inhibit the mycelial growth of G.graminis,thus reducing the disease occurrence and promoting the growth of wheat seedling.