Effects of Streptomyces misionensis TF78 on fusarium wilt of field-grown banana and rhizosphere soil microorganisms

Abstract:

[Background] Fusarium wilt of banana is a devastating disease in banana production. Biological control is an effective means to prevent the occurrence of this disease. In previous studies, Streptomyces misionensis TF78, a biocontrol strain, was isolated from the rhizosphere soil of healthy bananas, which showed good control effect on fusarium wilt of potted bananas. However, the biocontrol potential of S. misionensis TF78 against fusarium wilt of banana in the field and its impact on soil microbial environment are still unclear.[Objective] The paper was designed to evaluate the control effect of S. misionensis TF78 on fusarium wilt of banana in the field and determine its influence on the microbial communities in the rhizosphere soil of bananas. [Methods] The control effect of the biocontrol strain on fusarium wilt of banana was measured in two banana plantations. Microbial diversity and abundance of 12 rhizosphere soil samples from the inoculation group and the blank control group were analyzed by amplicon sequencing. [Results] The field control efficiency of S. misionensis TF78 on the two banana plantations were 55.30% and 45.32%. The slope for rarefaction curve of the inoculation group was larger than that of the blank control group, and Kickxellomycota was significantly enriched, while the abundances of Chloroflexi, Acidobacteria and Bryobacter were reduced. The biocontrol strain had no marked effect on the relative abundances of the dominant Proteobacteria, Firmicutes, Actinobacteria, Gemmatimonadetes, Trichoderma, Sphingomonas, Stenotrophomonas and Bacillus in the soil. [Conclusion] S. misionensis TF78 shaped the unfavorable soil environment to the survival of Fusarium oxysporum f. sp. cubense, and reduced the occurrence of fusarium wilt of banana in the field. Additionally, the strain failed to affect most of the dominant microbial populations with important ecological and bacteriostatic functions in the soil. The results lay a foundation for further development and application of S. misionensis TF78.