目的 探究不同地区黄芪根系细菌群落组成和多样性差异及其与土壤环境因子的相关性，以指导黄芪高产栽培。方法 采用高通量测序对陇西、渭源、岷县和漳县地区黄芪根际土壤和根内生细菌进行测序，对比分析其群落结构和多样性差异，并探究土壤理化因素与根系细菌群落的相关性。结果 黄芪根内生样本共获得1 769个OTU，其中541个OTU为共有，根际土壤样本共获得1 676个OTU，其中1 224个OTU为共有。黄芪的根内生样本中丰度最高的细菌门为Proteobacteria，细菌属为Pseudomonas，根际土壤样本中丰度最高的细菌门为Acidobacteria，细菌属为Sphingomonas。根内细菌群落的网络复杂度和稳定性高于根际网络，但根际细菌的生态位宽度高于根内。根内细菌群落的形成更容易受随机过程的影响。总氮、速效氮、有机质、脲酶和过氧化氢酶是影响根系细菌群落组成和多样性的主要因素。结论 不同地区黄芪根系细菌群落组成和多样性存在差异，且土壤理化对细菌群落影响较大，为黄芪根系细菌资源挖掘和品质的提高提供一定的理论基础。

Objective To explore the differences of bacteria community composition and diversity in root system of Astragalus membranaceus in different areas and their correlation with soil environmental factors, so as to guide the high-yield cultivation of A. membranaceus. Methods The rhizosphere soil and endophytic bacteria of A. membranaceus in Longxi, Weiyuan, Minxian and Zhangxian were sequenced by high-throughput sequencing, and the differences of bacteria community structure and diversity were compared and analyzed. The correlation between soil physical and chemical factors and root bacteria community was explored. Results A total of 1 769 OTU were obtained from endophytic samples of A. membranaceus, in which 541 OTU were common, and 1 676 OTU were obtained from rhizosphere soil samples, in which 1 224 OTU were common. In the root endophytic samples of A. membranaceus, the highest abundance of bacteria phylum was Proteobacteria, bacteria genus was Pseudomonas, and the highest abundance of bacteria phylum in rhizosphere soil samples was Acidobacteria, bacteria genus was Sphingomonas. The network complexity and stability of the bacteria community in the root were higher than those in the rhizosphere network, but the niche breadth of the bacteria in the rhizosphere was higher than that in the root. The formation of bacteria community in roots is more easily affected by random processes. Total nitrogen (TN), available nitrogen (AN), soil organic matter (SOM), urease (URE) and catalase (CAT) are the main factors affecting the composition and diversity of root bacteria community. Conclusion There are differences in the composition and diversity of root bacteria community of A. membranaceu in different areas, and the soil physics and chemistry has a great influence on the bacteria community, which provides a theoretical basis for the subsequent exploitation of rhizosphere bacterial resources and the improvement of quality.

R286.2

国家自然科学基金资助项目（32160066）；兰州理工大学青年人才计划（2018）