艾比湖湿地芦苇根际黏细菌群落多样性及其时空分布特征

Spatial and temporal distribution characteristics and diversity of myxobacteria in the rhizosphere of Phragmites australis in Ebinur Lake wetland

摘要:

【目的】研究艾比湖湿地芦苇根际土壤未培养黏细菌多样性、群落结构及其时空分布特征，提高对盐碱湿地等极端环境黏细菌资源的认知，为今后开发利用极端环境黏细菌资源奠定基础，也为艾比湖湿地盐漠生态系统修复提供数据支撑。【方法】采集艾比湖湿地10个样地3个月份的芦苇根际土壤，针对16S rRNA基因的V4–V5区使用高通量测序技术研究黏细菌多样性、群落结构及其时空分布特征。【结果】艾比湖湿地黏细菌16S rRNA基因Tags数占细菌的0.22%–3.54%，7月份和样地4的多样性最高，说明属多样性与季节和样地相关。本研究共鉴定到黏球菌目的3个亚目、8个科、14个属，其中海无柄孢囊黏细菌属(Haliangium)为优势属，占10.83%–71.01%。网络共现图表明绝大多数细菌与黏细菌存在相互作用。Spearman分析表明，细菌的Shannon、Chao1和ACE指数影响着黏细菌的多样性和丰富度。冗余分析(redundancy analysis, RDA)表明，土壤无机氮(inorganic nitrogen, IN)、有机质(organic matter, OM)和水溶性镁离子(Mg²⁺)是影响黏细菌多样性、群落结构的主要非生物因子。【结论】艾比湖湿地黏细菌资源丰富，其多样性、群落结构受时空变化影响。生物因素(细菌)和非生物因素(土壤理化性质)共同影响着黏细菌多样性。

Abstract:

[Objective] To study the spatial and temporal distribution characteristics, community structure, and diversity of uncultured myxobacteria in the rhizosphere soil of Phragmites australis in the Ebinur Lake wetland, so as to enrich the knowledge of myxobacteria resources in saline-alkaline wetlands, lay a foundation for exploiting the myxobacteria resources in extreme environments, and provide data support for the restoration of saline desert ecosystems. [Methods] The rhizosphere soil samples of P. australis were collected from 10 sites in Ebinur Lake wetland in 3 months, and high-throughput sequencing was conducted for the V4–V5 region of the 16S rRNA gene to reveal the diversity and spatial and temporal distribution of myxobacteria. [Results] The abundance of myxobacteria, as indicated by the presence of 16S rRNA gene tags, ranged from 0.22% to 3.54% of the total bacteria in the Ebinur Lake wetland. The highest diversity was observed in July and at the sampling site 4, suggesting the correlations of genus diversity with both seasons and sample sites. A total of 14 genera of myxobacteria belonging to 8 families of 3 suborders were identified. Among them, Haliangium was the dominant genus, with the relative abundance of 10.83%–71.01%. Network co-occurrence diagrams showed that most of the bacteria interacted with myxobacteria. Spearman correlation analyses showed that the Shannon, Chao1, and ACE indices of bacteria influenced the diversity and richness of myxobacteria. The redundancy analysis (RDA) showed that soil inorganic nitrogen (IN), organic matter (OM), and water-soluble magnesium ions (Mg²⁺) were the main abiotic factors influencing the diversity and community structure of myxobacteria. [Conclusion] The Ebinur Lake wetland is rich in myxobacteria, the diversity and community structure of which present spatial and temporal variations. Biotic factors (bacteria) and abiotic factors (soil physico-chemical properties) jointly affect the diversity of myxobacteria.