一株贝莱斯芽孢杆菌B18的分离纯化与鉴定及其对香蕉枯萎病的防效

Solation, Purification and Identification of a Bacillus velezensis B18 and its Control Effect on Banana Wilt

本试验主要研究了一株贝莱斯芽孢杆菌(Bacillus velezensis)B18对香蕉枯萎病病原菌尖孢镰刀菌古巴专化型热带4号生理小种(Fusarium oxysporum f.sp.cubense race 4,Foc TR4)的生物防治效果。在对木薯根际土壤微生物进行分析筛选时发现一株对Foc TR4生长有抑制作用的拮抗细菌B18,结合细胞形态判断、生化理化检测以及16SrDNA和gyrB基因的分子生物学分析对B18菌株进行鉴定。采用平板对峙法,分别探索了B18菌株的菌悬液、发酵上清液对Foc TR4的拮抗作用。在温室盆栽条件下,用B18菌悬液对香蕉幼苗灌根,探索其对由Foc TR4引起的香蕉枯萎病的防效。结果表明:B18菌株的菌悬液能有效抑制尖孢镰刀菌Foc TR4的菌丝生长,进一步盆栽实验发现B18菌株对由Foc TR4引起的香蕉枯萎病表现出明显的抗性,防效高达67.9%。研究结果表明B18在香蕉枯萎病防治中有一定的应用潜力和价值,可用做防治香蕉枯萎病的生防菌剂。

The biological control effect of a strain of Bacillus velezensis B18 on Fusarium oxysporum f.sp.cubense race 4(Foc TR4)was mainly studied in this study.During the analysis and screening of cassava rhizosphere soil microorganisms,an antagonistic bacterium B18 that inhibits the growth of Foc TR4 was found.B18 was identified by combining cell morphology judgment,biochemical physical and chemical testing and molecular biology analysis of 16SrDNA and gyrB genes.The plate confrontation method was used to explore the antagonistic effects of B18 bacterial suspension and fermentation supernatant on Foc TR4.In the greenhouse potted conditions,the banana seedlings were irrigated with B18 bacterial suspension to explore its control effect on banana wilt caused by Foc TR4.The results showed that the bacterial suspension of B18 could effectively inhibit the mycelial growth of Foc TR4.Further pot experiment found that B18 showed obvious resistance to banana wilt caused by Foc TR4.The control effect was as high as 67.9%.The research results show that B18 has certain application potential and value in the control of banana Fusarium wilt which can be used as a biocontrol agent for the control of banana fusarium wilt.