Stochastic processes contribute to arbuscular mycorrhizal fungal community assembly in paddy soils along middle and lower Yangtze River

Arbuscular mycorrhizal fungi (AMF) are extensively distributed in environment, and have key effects on regulating soil structure, nutrient cycles, crop productivity, and ecological processes in agricultural ecosystems. However, the biogeographic patterns and underlying ecological processes shaping AMF community assembly remain unclear. The present study examined AMF community composition and diversity in paddy soils along middle and lower reaches of the Yangtze River, and the driving factors and processes of AMF community assembly were assessed based on MiSeq sequencing. The results showed that soil pH, total N and Olsen-P, and soil organic matter (SOM) levels affected AMF community diversity. In addition, there were 4 orders, 8 families along with 8 genera within our study area, where Glomus was the most dominant genus. Moreover, AMF community composition was under the influence of geographic distance and soil characteristics such as pH, SOM, N and P contents, and enzyme activities. However, the contribution of deterministic processes was less than stochastic processes by the null model analysis, suggesting that stochastic processes was the dominant ecological processes shifting AMF community assembly in paddy soils along middle and lower reaches of the Yangtze River. The results sheds more lights on patterns as well as mechanisms driving the assembly of AMF communities within the agricultural ecosystems.