16S and ITS sequencing of peanut rhizosphere soil

The combination of biocontrol agent and biochar offers an environmentally friendly alternative for control of soil-borne diseases, which can effectively reduce reliance on traditional chemical pesticides. However, it remains unclear how biocontrol agent loaded biochar alleviate peanut wilt disease and its interactions with soil microorganisms. This study investigated the effects of Bacillus subtilis BT loaded biochar (BTBC) compared to the application of the biocontrol strain (BT) and biochar alone (BC) in controlling peanut wilt disease and its rhizosphere regulatory mechanisms. The results showed that compared with the disease control (FO), the BTBC significantly enhanced the abundance of B.subtilis in rhizosphere (by 2.7 times) and roots(by 65.3 times), reduced the disease index of peanuts (by 75%), and decreased the abundance of Fusarium oxysporum in the roots(by 94.7%), and enhanced the stability of the rhizosphere community. BTBC significantly increased the content of soil organic matter, available potassium, as well as the activity of chitinase, urease, and acid phosphatase, and notably improved the dry weight of peanut pods and photosynthetic parameters. In conclusion, the application of B.subtilis loaded biochar not only enhances the colonization of B.subtilis in the environment and its efficacy against the F.oxysporum-induced wilt disease, but also improved soil nutrients and microbial community stability. These findings provide new insights into the management and control for the peanut wilt disease.