轮作对农田土壤重金属形态、作物累积重金属的影响与丛枝菌根真菌（AMF）密切相关，但目前对轮作作物与AMF间的互作及其影响土壤重金属形态的根际过程与机理认识有限，制约了对重金属低富集轮作模式的理解。本项目拟在云南铅锌矿区周边农田，选取油菜-玉米和蚕豆-玉米两个最普遍的轮作模式，选择主要的污染元素镉，以根际过程为切入点，通过大田和盆栽试验，采用高通量测序、Tessier连续提取、高效液相色谱等技术，分析轮作对农田AMF群落生态的影响，及AMF 群落对轮作作物生长、矿质营养与镉累积的反馈影响，阐明轮作作物与AMF的互作效应；解析轮作作物与AMF互作的根际分泌物（低分子量有机酸、球囊霉素相关土壤蛋白、可溶性糖、氨基酸等）成分与含量的变化及其介导根际土壤镉形态的转化，揭示不同轮作模式根际镉形态转化过程的差异与机理。研究结果能丰富根际污染生态学的理论，为轮作调控农田AMF的群落与生态功能提供新的认识。

Crop rotation has a remarkable effect on accumulation of heavy metals in crops that associated with arbuscular mycorrhizal fungi (AMF) in farmlands. However, little is known about the rhizosphere processes and mechanisms for the interaction between rotation crop and AMF and its impact on speciation of heavy metals in soils, which constrain our knowledge on the rotation modes accumulating fewer heavy metals. Thus in this project, pot and field studies will be conducted to assess the rhizosphere processes in the farmlands around a lead and zinc mine site in Huize County, Yunnan Province. The study will focus mainly on two most common crop rotation modes (canola - maize and fababean - maize) and one main pollution element (cadmium) using high-throughput sequencing, Tessier sequential extraction, and high performance liquid chromatography. The research objects include: (1) To investigate the interaction between rotation crops and AMF based on analyzing effects of rotation on community ecology of AMF in farmlands and feedback effects of AMF community on the growth, mineral nutrition and cadmium accumulation of rotational crops. (2) To illustrate the changes in composition and content of rhizosphere exudates, including low molecular weight organic acids, glomalin related soil protein, soluble sugars, amino acids, and it mediates the transfer on rhizosphere cadmium speciation, during the course of interaction between rotation crops and AMF. (3) To reveal the differences and mechanisms on rhizosphere processes for transforming cadmium speciation in different rotational modes. The results will enrich the theory of the rhizosphere pollution ecology, and provide a new understanding on regulating indigenous AMF community and its ecological functions in farmlands by rotation.