西南马尾松外生菌根真菌多样性及分布格局的驱动机制研究

Ectomycorrhiza (ECM) as dominant mutualistic symbionts of forest tree species, play important multifunctional roles in the forest soil ecological processes. The distribution pattern and diversity of ECM fungi in recent years has become one of hot topics for mycorrhizal ecology research. This study would focus on the key scientific issues relevant to the mechanism of distribution pattern and diversity of ECM fungi in Pinus massoniana forests on the southwest of China, to reveal the characteristics of ECM fungal community structure and diversity along temporal (season and forest age) and spatial (elevation, aspect and slope position) scales by using the traditional morphological classification and a combination of modern molecular biology methods, to clarify driving factors of the distribution pattern and diversity of ECM fungi in P. massoniana forests by investigation and physicochemical analysis for stand sites, climate, vegetation, soil environmental factors and so on, to built the ecological mechanism model about the relationships between ECM fungal diversity and environmental factors, to further clarify the mechanism of main environmental factors (biotic and abiotic) driving the distribution pattern of ECM fungi diversity by using simulation experiments, to provide a scientific basis for the protection and management of ECM fungal biodiversity resources, the selection and breeding of excellent ECM strains, and the mycorrhizal application technology.

外生菌根作为森林树种具有优势地位的互惠共生体，在森林土壤生态过程中发挥着重要的多功能作用。近年来外生菌根真菌多样性及分布格局是已成为菌根生态学领域研究的热点之一。本研究针对西南马尾松外生菌根研究存在外生菌根真菌多样性及分布格局的驱动机制等关键科学问题，采用传统形态学分类与现代分子生物学技术相结合的方法，揭示时间（季节和林龄）和空间（海拔、坡向和坡位）尺度上马尾松外生菌根真菌群落结构和多样性特征；通过对立地、气候、植被和土壤等环境因子的调查与理化分析，阐明马尾松外生菌根真菌群落多样性分布格局的驱动因子，构建外生菌根真菌多样性与环境因子的生态机制模型；通过模拟试验进一步阐明主要环境因子（生物和非生物）驱动外生菌根真菌多样性分布格局的机理，为该区外生菌根多样性资源的保护管理、优良（食用/药用）菌根真菌选育和菌根应用技术提供科学依据。

外生菌根作为森林树种具有优势地位的互惠共生体，在森林土壤生态过程中发挥着重要的多功能作用。近年来外生菌根真菌多样性及分布格局是已成为菌根生态学领域研究的热点之一。本项目通过建立不同林龄和不同海拔梯度的马尾松调查样地，开展调查样地的小气候、植被群落和土壤性质等环境因子的监测，采用传统形态学分类与现代分子生物学技术相结合的方法进行外生菌根真菌鉴定，以及进一步采用宏基因组测序技术分析了样地土壤微生物组特征。结果表明：不同林龄和不同海拔马尾松林小气候均存在显著性差异(P<0.05)；马尾松外生菌根真菌侵染率约95%，马尾松外生菌根真菌存约70%左右的特有种，红菇属和棉革菌属为优势属；不同林龄的多样性指数呈现“单峰型”的变化趋势；而不同海拔马尾松林的多样性指数呈现的变化趋势不明显；海拔，土壤的pH、总磷、有效磷、有机碳，宿主的DBH等环境因子是影响马尾松外生菌根真菌多样性分布的重要影响因素。马尾松林土壤微生物群落（古菌、细菌、真菌和病毒）不同类群的时空分布规律存在明显差异。