Banana Fusarium wilt, caused by Fusarium oxysporum , is a highly destructive disease that threatens global banana production Biocontrol agents such as Pseudomonas chlororaphis P1 provide a sustainable strategy for disease management. However, how these agent influence indigenous rhizosphere microbiota under varying pathogen pressures remains elusive. This study evaluated the effects of P. chlororaphis P1 on the banana rhizosphere bacterial community across different F. oxysporum infection levels, High-throughput sequencing and quantitative PCR were employed to analyse rhizosphere soils following inoculation with P. chlororaphis P1. In soils heavily infested with F. oxysporum , P. chlororaphis P1 exerted no significant effect on community composition. In contrast, in soils with low pathogen levels, the bacterial abundance decreased markedly, and the structure and composition of the bacterial community underwent significant alteration. Notably, the genera Massilia and Pseudoxanthomonas played dual ecological roles: they were significantly negative correlation with Fusarium spp, but a significantly positive correlation with P. chlororaphis P1 ( p < 0.05). A significant negative correlation was also observed between the relative abundance of P. chlororaphis P1 and banana wilt disedse severity. This study demonstrated that Pseudomonas chlororaphis P1 possesses strong biocontrol efficacy against Fusarium wilt. However, in soils with low Fusarium abundance, P1 application reduced bacterial richness and diversity. These findings highlight the effectiveness of P. chlororaphis P1 for Fusarium wilt suppression, while underscoring the necessity to balance its disease control benefits against potential ecological impacts on endogenous soil microbial communities.
Song et al. (Sat,) studied this question.