番茄立枯病生防菌株B11-64的鉴定及其生防特性

Identification of Strain B11-64 and Its Biocontrol Characteristics Against Tomato Rhizoctonia Rot

以课题组前期筛选到的对番茄立枯病防效较好的生防菌株B11-64为材料,探究其分类地位和生防作用相关特性,为其田间应用提供科学依据。从形态学、生理生化特性以及16S rRNA序列等方面对生防菌株B11-64进行鉴定,测定该菌株的抑菌谱,并分析该菌株的生防相关特性。结果表明:B11-64为绿针假单胞菌,对苦瓜枯萎病菌、香蕉煤纹病菌、烟草茎点霉叶斑病菌等7种病原菌的平板抑制率均超过57%,其中,对香蕉煤纹病菌和烟草猝倒病菌的抑菌作用最强,抑菌率大于80%;该菌株能破坏立枯丝核菌的菌丝结构,形成生物膜能力较强,可代谢产生氢氰酸、嗜铁素;抗生素合成相关基因分析和薄层层析结果证实B11-64菌株可产生酚嗪-1-羧酸。以上结果表明B11-64菌株对番茄立枯病菌有较好的抑制活性,具有良好的开发和应用潜力。

A previously screened strain B11-64 with good biocontrol effect on tomato rhizoctonia rot(Rhizoctonia solani)was identified by the morphological,physiological and biochemical characteristcs and 16S rRNA sequence analysis to verify its taxonomic status.In addition,the antimicrobial spectrum of the strain was determined,and its biocontrol characteristics were studied.The results show that the biocontrol strain B11-64 is Pseudomonas chlororaphis,with 57.73%-80.81%of plate inhibition percentage against 7 plant pathogenic fungi.Especially,its plate inhibitory rates against banana helminthosporium leaf spot(Helminthosporium torulosum)and tobacco dampingoff(Pythium)were over 80%.The strain destroyed the mycelium structure of Rhizoctonia solani and formed strong biofilms.It could produce metabolites such as hydrocyanic acid(HCN)and ferritin.The analysis results of gene related to antibiotic synthesis and TLC show that B11-64 strain could produce phenazine-1-carboxylic acid(PCA).The above results indicate that B11-64 strain can inhibit R.solani effectively,and has potential for development and application.