青藏高原若尔盖湿地丛枝菌根真菌的群落构建及其碳汇功能研究

丛枝菌根(AM)是由球囊菌门真菌与植物根系形成的互惠共生体，在生态系统的植物多样性维持、群落演替以及物质循环过程中发挥重要的功能。青藏高原高寒湿地生态系统具有丰富的植物和微生物多样性及重要的生态功能，然而，目前对该系统中AM真菌群落的构建机制及其碳汇功能知之甚少。因此，为了揭示此科学问题，本项目拟以青藏高原若尔盖湿地国家自然保护区为地点，利用形态学、生物化学和DNA高通量测序等方法，检测不同植物根系和根围土壤中AM真菌的侵染结构、菌丝长度、孢子密度、多样性和球囊霉素相关土壤蛋白含量，通过AM真菌与植物、土壤等环境因子的相关性分析，揭示AM真菌群落的构建机制及碳汇功能；通过室内的稳定性同位素探针(SIP)和DNA高通量测序技术，阐明不同植物之间参与碳转运的AM真菌类群及其碳转运功能。本项目将从AM真菌的角度为全面揭示青藏高原高寒湿地生态系统的多样性维持机制及其碳汇功能提供重要的科学支撑。

Arbuscular mycorrhizal (AM) fungi, belonging to the phylum Glomeromycota, form mutualistic associations with most plant species and play critical roles in plant diversity maintenance, community succession, and substance global biogeochemical cycling. The alpine wetland ecosystem, located in the Qinghai-Tibetan Plateau, has high species diversity of plant and fungi and plays important ecological functions, however, the mechanism of AM fungal community assembly and its carbon sink size in this ecosystem remains largely unknown. Therefore, for targeting at this scientific question, the current project will be conducted in the National Nature Reserve for Zoige wetland in Sichuan Province. The AM fungal root colonization, extraradical hyphal density, spore density, glomalin-related soil protein and diversity in selected plant species and rhizospheric soil will be investigated, using morphological, biochemical and DNA pyrosequencing methods. The relationships between AM fungal properties and plant and soil factors will be further analyzed for exploring the community assembly and carbon sink capacity of AM fungi. Moreover, pot experiment combined with stable isotope probing (SIP) and DNA pyrosequencing techniques will be performed to compare the active AM fungal community and their carbon transferring function among different plant species. Based on the analyses of AM fungal characteristics, this project has pivotal implications in understanding biodiversity maintenance mechanism and relevant carbon sink function in the Zoige wetland ecosystem on the Qinghai-Tibetan Plateau.