新疆骆驼刺拮抗内生细菌XJAS-AB-13的分选·鉴定及其对玉米斑点病菌的生物防治潜能研究

[目的]从骆驼刺（Alhagi pseudalhagi Desv）内生菌中筛选出对农作物致病菌具有较强生物活性的拮抗菌株,活体验证拮抗菌株的生物防治能力。[方法]采用琼脂扩散法对常见的农作物致病菌做拮抗试验,结合传统病情统计和不同处理组玉米叶片中总蛋白含量以及防御酶活性测定活体验证拮抗菌株的生防能力。[结果]筛选出对玉米大、小斑点病菌具有较强活性拮抗菌株XJAS-AB-13,根据拮抗内生细菌XJAS-AB-13的生理生化特征以及16S rDNA序列分析将其最终鉴定为枯草芽孢杆菌。该菌株发酵液对玉米大斑病菌和玉米小班病菌的抑菌圈直径分别达32.8和24.6 mm。活体试验结果显示,发酵液对玉米小斑病菌和玉米大斑病菌的防效率分别达到45.00%和63.33%。[结论]拮抗菌株XJAS-AB-13在玉米大、小斑点病菌的生物防治中具有较好的应用潜力。

Screening and Identification of An Antagonistic Endobacterium ( XJAS-AB-13 ) from Xinjiang Alhagi pseudalhagi Desv and Studies on Its Biocontrol Potentials to Maize Spot Pathogens

[Objective] The aim was to screen antagonistic endophytes from Alhagi pseudalhagi Desv to common crop pathogens,and verify biocontrol capacity of the active strains with in vivo experiment.[Method] Agar diffusion method was used in screening the antagonistic endophytes.Traditional disease severity investigating method,measuring the total protein contents and defense enzymes activity of the maize leaf samples under the different treatment were used in testing the in vivo activity of the antagonistic strain.[Result] An antagonistic endobacterium(XJAS-AB-13) with strong antifungal activity to Exserohilum turcicum and Bipolaris maydis,was screened from Alhagi pseudalhagi Desv XJAS-AB-13 was finally identified as Bacillus subtilis according to physiological and biochemical characteristics and 16S rDNA sequence features.Inhibition zone diameter of fermentation broth of XJAS-AB-13 to Exserohilum turcicum and Bipolaris maydis reached 32.8 and 24.6 mm,respectively.in vivo experiment results showed that the biocontrol rate of XJAS-AB-13 to Bipolaris maydis and Exserohilum turcicum were 45.00% and 63.33%,respectively.[Conclusion] Screened endobacterium(XJAS-AB-13) has important potentials in bio-controlling of Exserohilum turcicum and Bipolaris maydis.