Rhizosphere fungi play an important role in agricultural ecosystems. Their activities and interactions greatly affect various ecosystem processes related to nutrient cycling, soil borne diseases and crop health. The aim of this study was to investigate the effects of rotation fallow mode of spring wheat, potato, fallow and spring wheat, rape, fallow on rhizosphere fungi community structure and functional fungi composition of spring wheat. In this paper, high-throughput sequencing and bioinformatics were used to systematically analyze the diversity, composition and abundance of functional fungi in the rhizosphere of spring wheat at flowering stage. The results showed that: compared with WWW, rotation fallow mode could increase the diversity of rhizosphere fungi and eliminate a small number of specific fungi; The dominant phylum of spring wheat rhizosphere fungi were Ascomycota (32.72-47.99%), Basidiomycota (8.39-34.21%) and Mortierellomycota (2.05-18.42%). Rotation fallow mode significantly increased the relative abundance of Mortierellomycota and Chytridiomycota; The relative abundance of Basidiomycota decreased significantly (P<0.05); By increasing the relative abundance of potentially beneficial genera of Mortierella, unidentified_Mortierellales_sp and Atractiella, Reducing the relative abundance of potentially harmful fungi genera of Fusarium, Plectosphaerella and Alternaria to a certain extent kept the soil healthy. Compared with other modes, WFP is most likely to cause rhizosphere fungi community structure to develop in favor of plant health.

Global warming poses a serious threat to agriculture and natural systems, in part because of the change of soil moisture content, which changes soil microbial communities and ecological processes. Soil water content is the main factor limiting the growth of plants in soil. Microbial communities rely on soil water to complete their activities, and reveal the changes of underground microbial communities under different soil moisture content, which will help us to further understand the potential impact of climate change on soil ecosystem. To investigate the soil bacterial community structure, we established experiment indoor in the West foot of Daxing’an Mountains with manipulative water content treatments consisting of 20%, 15%, 10%, 5%, 0%. Results showed that bacterial community composition varied significantly with altered drought stress , but community richness did not. The relative abundance of Actinobacteria increased with the increase of drought stress, Proteobacteria, Acidobacteria and Gemmatimonadota decreased with the increase of drought stress, actinobacteria was more likely to accumulate or maintain stable under drought stress, bacterial communities can responding directly to changes in soil moisture.