Effects of Funneliformis mosseae on the fungal community in and soil properties of a continuously cropped soybean system

Abstract Root rot leads to a substantial decline in the production and quality of soybean (Glycine max), particularly in continuous cropping systems. Therefore, it is important to explore methods and mechanisms for the biocontrol of root rot pathogens. In this paper, the fungal community structure in the roots and rhizosphere soil was determined by high-throughput sequencing technology under non-inoculated- and Funneliformis mosseae-inoculated conditions. Moreover, redundancy analysis (RDA) was used to analyse the effects of F. mosseae on the fungal community structure and the physical and chemical properties of the soil. In different samples (roots and rhizosphere soils), the fungal diversity index in HN48 was higher than that in HN66, while that without F. mosseae inoculation was slightly higher than that under inoculation with F. mosseae under different years of continuous cropping. Compared to those of non-inoculated plants, Fusarium oxysporum and Rhizoctonia solani were the dominant fungi in different root samples of soybean varieties. However, the predominant genera in the rhizosphere soil samples shifted with inoculation and comprised Fusarium, Mortierella, Cryptococcus, Guehomyces and Corynespora. Moreover, after inoculation with F. mosseae, the relative abundance of F. oxysporum and R. solani decreased in the roots and rhizosphere soils. Additionally, RDA showed that the rhizosphere soils showed significant differences depending on F. mosseae inoculation, continuous cropping year, and soybean variety. This study provides new insights into the interaction effects of arbuscular mycorrhizal fungi (AMF) and other fungi in continuously cropped soybean systems.