一株番茄青枯病生防细菌的筛选, 鉴定及其生防潜力分析.

【Objective】Tomato bacterial wilt caused by Ralstonia solanacearum (Rs) is main disease of tomato. In this study, the antagonistic strain against R. solanacearum and with growth promoting was screened from tomato rhizosphere, and its physiological and biochemical characteristic and biocontrol effect were investigated, which may provide a theoretical basis for the further development of biological control agents.【Method】Filter paper slice method was employed to screen the antagonistic strain against Rs. Physiological and biochemical characteristic and 16S rRNA sequences were analyzed to identify the antagonistic strain. Pot experiments were conducted to evaluate the biocontrol and growth promoting effects of the antagonistic strain on bacterial wilt and tomato, respectively. 16S rRNA gene amplicon sequencing and fluorescence quantitative PCR were used to investigate the effect of antagonistic strain on the bacterial community in tomato rhizosphere.【Result】An antagonistic strain A72 was screened out from the tomato rhizosphere. Strain A72 was identified as Bacillus siamensis by 16S rRNA gene sequence, and it had the ability to resolve phosphorus, release potassium, produce IAA, secrete extracellular hydrolases and siderophore, and form biofilms. The pot experiments showed that its control effect against tomato bacterial wilt was 63.80%, and it significantly increased the root length, plant height, dry weight, fresh weight and chlorophyll content of tomato plants. Application of strain A72 significantly decreased the density of R. solanacearum and altered the structure and composition of bacterial community in tomato rhizosphere.【Conclusion】Strain A72 has a good growth promotion effect on tomato seedlings and may effectively control tomato bacterial wilt. [ABSTRACT FROM AUTHOR]