宿主植物多样性对叶际细菌群落构建的影响机制研究

叶际细菌是存在于植物叶片表片和内部的细菌，是生态系统生物多样性的重要组成部分，对生态系统关键过程和功能的维持起重要作用。叶际细菌群落的构建受确定性过程和随机性过程的共同影响，而宿主植物多样性可通过影响这两个过程的相对重要性来影响叶际细菌群落结构，但相关机理缺乏研究。本项目拟在华南亚热带生物多样性与生态系统功能关系（BEF）实验平台开展，于不同多样性梯度的样方中采集植物叶片样品，提取叶际外生和内生细菌；通过16S rRNA基因测序检测细菌群落的物种组成，揭示驱动叶际细菌群落构建的生态学过程与机制，并探讨宿主植物多样性对叶际细菌群落构建中不同生态过程重要性的影响。本项目研究成果将为森林多样性丧失背景下了解微生物群落构建过程和机制提供科学依据和数据支持。

Phyllosphere bacterial community, including both epiphytic and endophytic components, is an important part of forest ecosystems and plays a prominent role in maintaining ecosystem processes and functions. Phyllosphere bacterial communities are shaped by both niche-based deterministic processes and neutrality-based stochastic processes, and diversity in host plant communities may alter the assembly of the phyllosphere microbial communities through changing the relative importance of these two processes. Understanding the relative importance of these ecological processes in determining phyllosphere bacterial assembly and its response to changes in host plant diversity is essential, but has not been explored. Our proposed project will be conducted in a forest biodiversity and ecosystem functioning (BEF) experiment in southern China, where we will collect leaf samples in plots with one, two, four, and eight tree species. Phyllosphere epiphytic and endophytic bacteria will be extracted and bacterial composition and diversity of the samples will be determined via high-throughput sequencing. We aim to explore the ecological processes and mechanisms regulating the assembly of phyllosphere bacterial community, and understand how the relative importance of different ecological processes changes with host plant diversity. Our proposed work will provide us a more complete understanding of the effects of host diversity on the assembly of microbial communities in the face of global biodiversity loss.