N^+离子注入枯草芽孢杆菌选育小麦全蚀病菌高效拮抗菌

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

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和促进麦苗的生长。

In order to improve the antagonistic ability of Bacillus subtilis AZ and search for high-effi- cient 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 Gaeumannomy- ces 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 in- dicated 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 my- celial growth of G. graminis,thus reducing the disease occurrence and promoting the growth of wheat seedling.