Temporal dynamics of fungal communities in soybean rhizosphere

Purpose: Many biotic and abiotic factors influence the structural and functional diversity of microbial communities in the rhizosphere. This study aimed to understand the dynamics of fungal community in the soybean rhizosphere during soybean growth and directly compare the influence of abiotic and biotic factors in shaping the fungal communities across different growth periods. Materials and methods: High-throughput sequencing based on internal transcribed spacer (ITS) region, quantitative PCR, and statistical analysis approaches were used to measure the fungal community structure, abundance, and dynamic changes of 63 rhizosphere soil samples which were taken from different fertilization regimes and rhizobium inoculation treatments during three soybean growth stages. Results and discussion: Among the taxa examined, more than 16 fungal classes were detected from the 21 soil samples. Sordariomycetes was the most abundant class, followed by Dothideomycetes, Agaricomycetes, and Eurotiomycetes. Soybean growth stage was the most important factor determining the diversity patterns of the fungal communities. Fungal community diversity was closely related to the base-fertilizer application, and fungal community richness was associated with rhizobium inoculation. Beta diversity of the fungal community based on the Bray-Curtis distance was significantly related to plant growth stage. Network analysis showed that mutual cooperation among fungal taxa became more intimate during the plant growth. Conclusions: Compared with edaphic properties, plant growth stage was the dominant factor in determining soil fungal community dynamics. Base-fertilizer and rhizobium inoculation affected the alpha diversity of the soil fungi.