Screening of antagonistic bacteria against Streptomyces scabies and identification of BKS104

Abstract:

[Background] In recent years, the damage of potato scab disease has gradually increased, and it has occurred in all major producing areas across the country. At present, the lack of effective prevention and control methods has caused serious economic losses. Biological control is an effective way to prevent and control soil-borne diseases, and has gradually become a research hotspot. [Objective] Screening strains with high antagonistic effect on Streptomyces scabies will provide strain resources for the development of biocontrol agents and lay a theoretical foundation for the prevention and control of potato scab. [Methods] The isolated strains were preliminarily screened and re-screened by the plate confrontation growth method and the Oxford cup test method, and the strains were identified by morphological characteristics, physiological and biochemical characteristics, and 16S rRNA and gyrB sequence analysis results. The antifungal spectrum of the strain was determined by the plate confrontation method. [Results] A strain BKS104 with obvious antagonistic effect was obtained, with a antifungal diameter of 43 mm and a control effect of 85%. The colony is round, milky white, opaque, shiny surface, neat edges, rod-shaped bacteria, Gram-positive bacteria. Combined with the sequencing results of 16S rRNA and gyrB, it was identified as Bacillus velezensis, and it has inhibitory effect on 8 kinds of plant pathogenic fungi. [Conclusion] The strain BKS104 is B. velezensis, which can effectively inhibit the growth of Streptomyces scabies, with high safety and good biocontrol potential.