烟草黑胫病拮抗菌XA-1的筛选·鉴定及其抑制作用研究

Screening,Identification and Inhibiting Effect of Antagonistic Bacterium XA-1 against Tobacco Black Shank

[目的]有效预防和控制恩施种植区域烟草黑胫病害。[方法]通过表面消毒分离、平板共培养、分子生物学鉴定、室内盆栽方法筛选、鉴定及评价菌株抑制活性。[结果]从恩施健康烟草植株中分离筛选出一株对烟草黑胫病病原菌有显著拮抗活性的菌株XA-1,该菌株的胞外分泌物对病原菌菌丝有强烈的抑制作用,通过Biolog微生物系统和分子生物学分析,初步鉴定该菌株属于解淀粉芽孢杆菌(Bacillus amyloliauefaciens),经室内盆栽试验评价,拮抗菌XA-1能有效地降低烟草黑胫病的病情指数,在第20天时相对防效最高为52.38%。[结论]菌株XA-1在防治烟草黑胫病方面效果明显,具有潜在的生物防治应用价值。

[Objective]To control the tobacco black shank disease in the tobacco growing area effectively.[Method]Screening and identification and inhibiting effect of an antagonistic bacterium were conducted through surface disinfection separation,confrontation culture,molecular biological identification and potting trial.[Result]A strain,XA-1,was obtained by rapid initial screening of pathogenic from bacteria tobacco roots in Enshi.XA-1 strain had significant antagonistic activity against Phytophora nicotiana.It was verified that the antibacterial substance of the strain was extracellular secretion.According the biolog system analysis and molecular taxonomy and identification,the strain XA-1 was identified as Bacillus amyloliauefaciens.Potting trial showed that the disease index of tobacco plants which treated with strain XA-1 was decreased and the highest relative biological control efficacy was up to 52.38%.[Conclusion]The XA-1 can significantly prevent tobacco blank shank disease,so it has potential application value in biological control of tobacco black shank.