香蕉枯萎病拮抗菌贝莱斯芽胞杆菌的筛选鉴定及其生物学特性

Screening,Identification and Biological Characteristics of Bacillus velezensis with Antagonst Activity against Banana Fusarium Wilt

香蕉枯萎病是目前香蕉产业面临的毁灭性病害,目前尚无特别有效的防治药剂。为发掘香蕉枯萎病的生防菌资源,本研究通过初筛和复筛获得两株对香蕉枯萎病菌具有较强拮抗活性的菌株Blz67和Blz02。依据形态学观察及生理生化测试结果,并结合16S rRNA和gyrA基因序列分析,将两株拮抗菌鉴定为贝莱斯芽胞杆菌Bacillus velezensis。生物学特性测试结果表明:两株拮抗菌的最适生长温度均为31℃,最适生长pH均为5.5。盆栽试验结果表明,菌株Blz02与Blz67对香蕉枯萎病的防效分别为63.33%和40.00%,在香蕉枯萎病的生物防治上具有较好的应用前景。

Banana Fusarium wilt caused by Fusarium oxysporum f.sp.cubense(Foc)is a destructive disease in global banana industry.Till now,there is still no means available for effective control of the disease in field.In order to explore the biocontrol agents against banana Fusarium wilt,two antagonistic bacterial strains Blz67 and Blz02 were screened out by primary and secondary selections.The two strains were both identified as Bacillus velezensis by morphological observations,physiological and biochemical tests,combined with 16S rRNA and gyrA gene sequences analysis.The results of biological characteristics tests showed that the optimum temperature for growth of both strains were 31℃,and the optimum pH value both were 5.5.The control efficacies of the strains Blz02 and Blz67 against banana Fusarium wilt in green house were 63.33%and 40.00%under greenhouse conditions,respectively,indicating that both strains had a promising prospect in biological control of banana Fusarium wilt.