生防菌Bs-916及高效突变菌株抗菌物质及其对水稻抗性诱导作用的研究

 枯草芽孢杆菌Bs-916是一种有效防治水稻病害的生防菌,为进一步提高其拮抗性能,获得更好的生防效果,运用离子注入(N+)的方法对Bs-916进行诱变,筛选到4株拮抗性能比出发菌Bs-916提高15%以上的菌株。TLC和HPLC定性、定量分析比较结果表明,Bs-916及其突变体分泌的脂肽类抗生素是表面活性素,突变菌株分泌的表面活性素比出发菌株有不同程度提高。室内抑菌结果表明,表面活性素能抑制纹枯病菌菌丝生长,引起原生质泄露。通过检测接种纹枯病菌、拮抗菌Bs-916及其突变菌株的水稻植株体内过氧化物酶(POD)、多酚氧化酶(PPO)和超氧化物歧化酶(SOD)酶活性的变化,发现拮抗菌Bs-916及其突变菌株分泌活性物质对水稻具有诱导抗性作用;4个高效突变株比出发菌Bs-916对3种酶的活性影响加大;同时接种拮抗菌和纹枯病菌比单独接种拮抗菌、纹枯病菌对3种酶活性影响大。

Antifungal substances producted by a high-yielding mutant of Bs-916 and their effects inducing-resistance on rice plant

Bacillus subtilis 916 is an important biocontrol bacterium in controlling rice diseases.In order to further improve the growth rate and antagonistic ability of the strain and obtain high-efficiency strains,N+ of different doses were implanted into Bs-916.Antagonistic ability of the screened four mutant strains increased 15% compared with the host Bs-916 strain.The results of TLC and HPLC analysis indicated that the lipopeptides produced by Bs-916 and the mutant strains were belonged to the surfactin family.The four mutant strains produced more surfactin compared with that of the parental strain.The surfactin inhibited mycelial growth and caused the vesicle structures in the tips of hyphae,then the cell wall broken and the protoplasm leaked out on the screening plate.The enzymes of POD、PPO and SOD as indicators of resistance to plant disease were selected and compared.The activities of three enzymes were various after the rice inoculated with Bs-916 and high-yield mutant strains.The results showed that the efficacy to three enzymes by inoculating antistrains and Rhizoctonia solani simutanously was higher than that of inoculating single R.solani or antistrains.The effects of enzyme activities by four high effective mutant strains were higher than that of Bs-916.