云南亚高山地区建群树种长苞冷杉的外生菌根菌群落研究

Ectomycorrhizal fungi form an important component in forests, which is vital in maintaining the balance of forest ecosystems. It is now a hot topic to study ectomycorrhizal fungal diversity and community by using molecular approaches. Despite of few successful case studies in subtropic and temperate regions, ectomycorrhizal study based on molecular data is still limited in China. In Southwest China, one of the global biodiversity hotspots, few studies on ecotomycorrhizas have been sporadically reported, and studies from subalpine areas of this region are still very rare. In this proposed project, we intend to select Abies georgei, one of the constructive tree species in subalpine areas of Yunnan Province, as our research subject. Forests from different locations, with different tree compositions, and in different stages of succession will be set as plots, where fungal fruiting bodies and ectomycorrhizal materials will be sampled in different seasons. By analyzing these samples with Sanger and High-throughput sequencings, we aim to uncover the diversity of ectomycorrhizal fungi associated with A. georgei, to reveal the spatio-temporal distribution pattern of ectomycorrhizal communities, and to detect the potential impacts on shaping the composistion of ectomycorrhizal fungal communities by growing seasons, distribution areas, succession stages of plant community, and host preference. This project will fill the gap in molecular study on ectomycorrhizas from subalpine areas of Southwest China, and will enrich our knowledge in ectomycorrhizal fungal diversity and community structure in this region. Moreover, it will provide theory foundations for local ecological protection and vegetation restoration.

外生菌根菌是森林生态系统的重要组成部分，对维系该系统的平衡极为重要。采用分子手段认识外生菌根多样性和群落结构是当前研究热点。我国外生菌根研究相对滞后，虽有亚热带和温带地区研究的成功案例，基于分子数据的外生菌根研究仍极为有限。中国西南这一重要的生物多样性热点地区仅有零星的外生菌根研究报道，亚高山区域的研究更是鲜见。本项目拟以云南亚高山地区建群树种之一长苞冷杉为研究对象，选择不同地点、不同植被组成和不同植物群落演替阶段的森林作为样地，在不同季节采集真菌子实体和菌根材料，结合Sanger和高通量测序数据进行分析，全面认识长苞冷杉的外生菌根菌多样性，揭示其外生菌根菌群落结构及时空分布特征，探讨季节、分布地区、植物群落演替阶段和宿主偏好性等对外生菌根菌群落组成的影响。本项目将填补西南亚高山地区外生菌根研究的空白，丰富人类对该区外生菌根菌多样性和群落结构的认识，为当地的生态保护和植被恢复提供理论依据。

外生菌根菌是森林生态系统的重要组成部分，对维系该系统的平衡极为重要。中国西南是重要的生物多样性热点地区，但仅有零星的外生菌根研究报道，亚高山区域的研究更是鲜见。冷杉属植物是西南亚高山地区重要的建群树种，但对其外生菌根的研究十分匮乏。本研究在云南省德钦县白马雪山和西藏自治区墨脱县嘎隆拉山采集土壤和菌根样品，结合ITS2扩增子测序，对其外生菌根真菌多样性和群落组成的时空变化规律以及其宿主专一性等开展研究。研究发现：(1)来自26个系统发育支系（phylogenetic lineage）42个属267个OTUs及1394个ASVs的外生菌根真菌能够与冷杉形成外生菌根共生关系。其中，担子菌门的丝膜菌属（Cortinarius）、红菇属（Russula）和子囊菌门的空团菌属（Cenococcum）等是较为优势的类群； (2)不同采集地、海拔和季节冷杉的外生菌根真菌群落组成均差异显著；（3）外生菌根真菌对宿主植物具有明显的宿主专一性，但这是与土壤理化因子和海拔等非生物因子共同作用的结果；（4）有效氮的变化对外生菌根真菌群落组成的季节性变化具有重要影响。本研究为认识西南地区亚高山外生菌根真菌多样性和群落组成的时空分布规律及其驱动因子提供了范例，丰富了对西南地区外生菌根真菌的认识，为当地的生态保护和植被恢复提供了理论依据。