microbial diversity on eggplant rhizosphere soil

Eggplant Verticillium wilt is a devastating soil-borne disease affecting eggplant cultivation. Spent mushroom substrate (SMS) has shown promise as a soil amendment for controlling soil-borne diseases. We evaluated the efficacy of SMS in suppressing Verticillium wilt and investigated mechanisms related to rhizosphere microbiome regulation. 16S rDNA sequencing revealed alterations in rhizosphere bacterial communities, with an increase in indigenous beneficial bacteria, particularly Bacillus spp., following SMS amendment. SMS co-inoculated with exogenous biocontrol strain Bacillus subtilis NCD-2 achieved a synergistic effect against eggplant Verticillium wilt than both SMS or NCD-2 alone. Overall, our results demonstrated that SMS protects eggplants against eggplant Verticillium wilt, largely by recruiting Bacillus spp. to the rhizosphere. The enrichment effect of indigenous Bacillus spp. in the rhizosphere mediated by SMS similarly applies to Bacillus inoculum, enhancing its efficacy in controlling eggplant Verticillium wilt. These findings enhance our understanding of the protective effects of SMS and its role in the biocontrol of eggplant Verticillium wilt.