湿地植物根际微生态系统对土壤有机磷形态转化的作用机制

植物在湿地生态系统磷循环及面源污染控制中起着非常关键的作用，植物根际区域则是作用的核心。有机磷作为湿地磷的重要组成部分，其形态转化将直接影响湿地水体水质。因此，研究植物根际微环境对有机磷形态转化的影响具有非常重要的理论和实际意义。本项目拟从植物根际微生态系统学角度出发，研究不同湿地植物根际土壤及其溶液中磷酸酶活性的动态分布规律；探讨根际土壤及其溶液中不同形态有机磷含量与磷酸酶活性的关系；基于分子生态学技术，研究湿地植物根际土壤微生物群落结构及多样性的动态变化；采用根箱培养法，研究不同环境条件下植物根际微生物群落结构和磷酸酶活性的分布特征及其对土壤有机磷形态转化的耦合作用机理；通过克隆测序，鉴定植物根际优势菌群并探讨其演替规律；进而从基因水平揭示植物根际微生态系统在湿地磷生物地球化学循环中的作用机制，为充分发挥植物在利用磷素、减缓面源污染、保障湿地生态功能等方面的作用提供科学依据。

Plants play a crucial role in phosphorus cycling and non-point pollution control for wetland ecosystems. Plant rhizosphere is the core active area. As an important part of soil phosphorus, the transformation of organic phosphorus will affect wetland water qualities directly. Therefore, to study the influence of plant rhizospheres on the transformation of organic phosphorus has a theoretical and practical significance. From the perspective of plant rhizosphere microecosystem, this project intends to study the dynamic distribution of phosphatase activities in soils and its solutions collected from different plant rhizospheres. The relationship between different forms of organic phosphorus and phosphatase activities will then be explored. Based on molecular ecology techniques, the dynamic changes of microbial community structures as well as its diversities in plant rhizospheres will be analyzed. The root box cultivation method will be applied to study the distribution characteristics of microbial community structures and phosphatase activities in plant rhizospheres under different conditions. The coupling effect of microbe and phosphatase on the transformation of soil organic phosphorus will then be discussed. By gene cloning and sequencing, the dominant microflora in plant rhizospheres will be identified and its succession rules will be discussed. After that the mechanism of plant rhizosphere microecosystem on phosphorus biogeochemical cycling will be revealed at genetic level. The results will provide scientific proofs for plants to play a full role in utilizing phosphorus, slowing down non-point source pollution, as well as keeping ecological functions of wetlands.