ARC microbial inoculants promote peanut growth and yield while suppressing Aspergillus flavus infection

Peanuts are important oilseed legume crops that are susceptible to contamination by Aspergillus flavus in soil, leading to serious economic losses. Previously, our research team developed the Aspergillus- Rihizobia coupling (ARC) microbial inoculants and found it can reduce A. flavus abundance in the soil and promote efficient nodulation in peanuts. However, the impact of ARC microbial inoculants on different resistant varieties of A . flavus remains unclear. In this study, we screened peanut varieties that were resistant and susceptible to A. flavus and evaluated their nodulation ability and growth performance after ARC microbial inoculants treatment in the field. The results demonstrated that the nodule number and nitrogenase activity of both varieties significantly increased after ARC microbial inoculants treatment, with the highly susceptible variety AH24 showing a greater increase. For photosynthetic parameters, both varieties also increased after ARC microbial inoculants treatment, but the increase was greater in the moderately resistant variety AH1 than in the highly susceptible variety AH24. Finally, we found that the yield and yield-related traits of the moderately resistant variety AH1 were better than those of the highly susceptible variety AH24. After ARC microbial inoculants treatment, the yield traits of both peanut varieties still increased significantly, but the degree of increase of the moderately resistant variety AH1 was smaller than that of the highly susceptible variety AH24. In addition, the abundance of A. flavus in the rhizosphere soil of the two varieties significantly decreased after ARC microbial inoculants treatment, with no significant difference between the varieties. These results indicated that ARC microbial inoculants exert differential effects on the nodulation and growth of different resistant peanut varieties and have a better effect on highly susceptible varieties. These results provide a solid theoretical basis for the efficient use of ARC microbial inoculants in the field of peanuts in the future.