玉米内生拮抗细菌枯草芽孢杆菌A16对小斑病菌拮抗作用的研究

Study on antagonistic entophytic bacteria Bacillus subtilis A16 in sweet corn against Bipolaris maydis

从甜玉米植株中分离获得90株内生细菌菌株,用平板对峙法获得对玉米小斑病菌有较强拮抗作用的菌株A16。抑菌谱测定表明,A16对多种病原真菌均有明显的拮抗作用。A16对甜玉米种子的萌发没有明显的抑制作用,且显示有一定的促生作用。苗期盆栽表明,经A16处理过的甜玉米植株的玉米小斑病的病情指数比对照低46.3。经形态学观察、生理生化反应及16SrDNA序列同源性分析,鉴定A16为枯草芽孢杆菌。最佳培养条件为:LM培养基、28～32℃、pH6.0、振荡培养36h。

A total of 90 bacteria strains were isolated from sweet corn by dilution plate method. Among these strains, A16 was screened out by antagonistic assay to Bipolaris maydis. The antimicrobial spectrum test showed that A16 had a wide range of antagonism against some pathgens. The tests of sweet corn seed germination showed that A16 did not significantly inhibit germination rate, and could promoted growth of sprout.Pot trials showed that after treated by A16, the disease index of sorthern leaf blight of maize effectively decreased. According to the results of morphological observation, physiological and biochemical reaction, analysis of the sequences of 16S rDNA, the A16 was identified as Bacillus subtilis. The ideal cultural conditions for A16 were LM cultural media, pH 6.0, cultural time 36 h, and temperatures 28℃～32℃.