多功能菌B1514在小麦根际的定殖及对纹枯病的防治作用

为明确多功能菌B1514对小麦纹枯病的防治效果，采用紫外诱变和逐步提高诱导浓度法筛选获得抗性菌株，分析其在小麦根际和根内的定殖动态，通过盆栽和微区试验测定其对纹枯病的防治作用。结果表明，用发酵液浸种后B1514在小麦根际和根内定殖时间分别达49 d和28 d以上；添加玉米秸秆可延长其在根际和根内的定殖时间。B1514发酵液浸种对小麦纹枯病的盆栽防效低于对照药剂60 g/L戊唑醇悬浮种衣剂；土壤中添加秸秆能提高发酵液浸种处理的防效，可达85.3%，且与戊唑醇无显著差异。田间试验结果显示B1514浸种同时添加发酵物处理的持效期较长，在小麦成熟期防效优于戊唑醇，为55.2%；秸秆降解率也高于对照，为45.5%。表明B1514有加速玉米秸秆降解和防治小麦纹枯病的作用。

Colonization of multi-functional bacterium B1514 in rhizosphere and its control effect on wheat sharp eyespot

Colonization of multi-functional bacterium B1514 in rhizosphere and in roots of wheat was assayed using the antibiotic resistant mutation strains as screening marker by UV-irradiating and increasing induction concentration of antibiotic gradually, and its control effect on wheat sharp eyespot was determined using pot culture and field test. The results showed that B1514 could colonize in rhizosphere or in roots more than 49 or 28 days after treatment by soaking seeds with fermentation broth, respectively. And the colonization time could be lengthened by adding maize straw into the soil. The control effect of soaking seeds with B1514 was significantly lower than that of tebuconazole 60 g/L FS in pot experiments. But the control effect of soaking seeds could be increased by 85.3% with maize straw added into the soil, and there was no significant difference with the tebuconazole. In field experiments, the persistence of seed-soaking and fermentation product of B1514 was longer than that of tebuconazole at maturity stage with a control effect of 55.2%. The degradation rate of maize straw reached up to 45.5% and higher than that of the control. These results indicated that the strain B1514 had a good effect on accelerating the degradation of maize straw and controlling wheat sharp eyespot.