Isolation, screening and identification of antagonistic bacteria against Verticillium dahliae Kleb. in Xinjiang

Abstract:

[Background] Cotton Verticillium wilt, caused by Verticillium dahliae Kleb., is one of the most devastating diseases. Biological control has been drawn more and more attention in recent years for its safety to environment, human and animal. [Objective] In order to expand strain resources for biological control of cotton Verticillium wilt, we urge to isolate, screen and identify highly efficient antagonistic bacteria against Verticillium dahliae Kleb. [Methods] The bacteria were isolated by spread plate method, the antagonistic bacteria were obtained by primary screening and subsequent screening. Strains were identified based on morphological, physiological and biochemical characteristics and 16S rRNA gene sequence analysis. [Results] 535 strains of antagonistic bacteria were primarily isolated and 108 strains of them were further tested. Finally, four highly efficient antagonistic bacteria were screened. Based on morphological, physiological and biochemical characteristics and 16S rRNA gene sequence analysis, strains BHZ-29, SHT-15, SHZ-24 and SMT-24 were preliminarily identified as Bacillus velezensis, Bacillus subtilis subsp. spizizenii, Bacillus atrophaeus and Bacillus vanillea, respectively. [Conclusion] Four highly efficient antagonistic bacteria were obtained and the inhibition effect of Bacillus vanillea on cotton Verticillium wilt was reported for the first time.