Banana disease-suppressive soil drives Bacillus assembled to defense Fusarium wilt of banana

Abstract

Fusarium wilt of banana (FWB) caused by <i>Fusarium oxysporum</i> f. sp. <i>cubense</i> tropical race 4 (<i>Foc</i> TR4), poses a serious problem for sustainable banana production. Biological control is one of the effective measures to control this destructive disease. High-throughput sequencing of soil microorganisms could significantly improve the efficiency and accuracy of biocontrol strain screening. In this study, the soil microbial diversity of six main banana-producing areas in Yunnan was sequenced by Illumina Miseq platform. The outcome of this study showed the genus of <i>Chujaibacter</i>, <i>Bacillus,</i> and <i>Sphingomonas</i> were significantly enriched in microorganism community composition. Further correlation analysis with soil pathogen (<i>Foc</i> TR4) content showed that <i>Bacillus</i> was significantly negatively correlated with pathogen content. Therefore, we isolated and identified <i>Bacillus</i> from the disease-suppressive soils, and obtained a <i>B. velezensis</i> strain YN1910. <i>In vitro</i> and pot experiments showed that YN1910 had a significant control effect (78.43-81.76%) on banana Fusarium wilt and had a significant growth promotion effect on banana plants.