青藏高原湿地不同微地形土壤甲烷氧化菌的群落结构与活性特征研究

踏头和踏间是青藏高原湿地普遍存在的微地形，有研究表明踏间土壤甲烷排放显著高于踏头土壤。甲烷氧化菌可消耗湿地产生甲烷的约90%，是影响甲烷排放的重要因素。阐明甲烷氧化菌在不同微地形土壤的特征是理解踏头踏间甲烷排放差异的基础。目前对青藏高原重要的湿地类型——湖泊湿地和河流湿地尚未有微地形影响甲烷氧化菌群落结构和活性的研究报道。本项目拟以青藏高原上具有代表性的纳木错湖泊湿地和那曲河流湿地为研究地点，用pmoA实时定量PCR、焦磷酸测序及mmoX克隆测序等技术分析不同微地形土壤甲烷氧化菌数量和群落结构差异，并结合环境数据分析控制群落结构的主要环境因子；通过稳定性同位素标记DNA的技术，检测16S rRNA基因和mmoX基因，分析不同微地形土壤活跃参与甲烷氧化的甲烷氧化菌类群。从而阐明不同微地形土壤之间甲烷排放差异的微生物机理，为更准确地模拟和评估青藏高原地区甲烷循环和碳循环提供理论和数据支持。

Hummock-and-hollow microtopography is common in wetlands of the Qinghai-Tibetan Plateau. The methane emission fluxes of the hollows are significantly higher than those of the hummocks. About 90% of the methane formed in wetlands is consumed by methanotrophs and never reaches the atmosphere. Therefore, in order to understand the distinction of methane emission fluxes, it is important to know the characteristics of methanotrophs in hummocks and hollows. Few researches have focus on the effects of microtopography on the community structure and activity of methanotrophs in lake wetland and river wetland on the Qinghai-Tibetan Plateau. The Namco lake wetland and Nagqu river wetland are selected as the study sites. The methanotroph community will be analyzed by qPCR. The pmoA genes will be analyzed by amplicon pyrosequencing and the mmoX genes by cloning and sequencing. Canonical correspondence analysis will be used to analyze the methanotrophs community data and environmental data to find the main environmental factors controlling the distribution of methanotrophs. In order to detect the active methanotrophs involved in the methane oxidation, stable isotope-labeled DNA technology will be used to detect 16S rRNA gene and mmoX gene. This project aims to provide the microbiological mechanism for understanding the differences of methane emission fluxes in different microtopography, and provide the theory and data support for more accurate simulation and evaluation of methane and carbon cycles on the Qinghai-Tibetan Plateau.