不同季节艾比湖湿地盐角草根际nirS-型与nirK-型反硝化细菌群落组成分析

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 不同季节艾比湖湿地盐角草根际nirS-型与nirK-型反硝化细菌群落组成分析 DOI: 10.5846/stxb202011112920 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31160026);国家自然科学基金项目(31560040) Community composition of nirS-type and nirK-type denitrifying bacteria in rhizosphere of Salicornia europaea in the Ebinur Lake Wetland during different seasons Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:旨在了解艾比湖湿地盐生植物盐角草根际与非根际中不同类型反硝化细菌的分布及其随季节变化情况,为温带干旱地区荒漠盐化生态系统的代表-艾比湖湿地在生态植被恢复过程中,由微生物推动的土壤氮素循环过程提供数据支撑。采集了艾比湖湿地夏、秋、春三个季节的盐角草根际和非根际土壤样本,通过高通量测序技术,比较分析了nirS-型和nirK-型两种类型的反硝化细菌的多样性和群落结构特点;利用RDA (redundancy analysis)探究了土壤理化因素对反硝化细菌多样性及群落结构的影响。艾比湖湿地盐角草根际与非根际中,nirS-型和nirK-型反硝化细菌多样性最高的为秋季根际土壤样本;各土壤样本中的反硝化细菌多样性均呈现根际>非根际。盐角草各土壤样本中的nirS-型反硝化细菌在门分类水平上隶属于变形菌门(Proteobacteria),厚壁菌门(Firmicutes)和放线菌门(Actinobacteria),而nirK-型反硝化细菌在门水平上分类仅包括了Proteobacteria和Firmicutes。Proteobacteria在各土壤样本中的占比均较高;其中Gamma-Proteobacteria的盐单胞菌属(Halomonas)和假单胞菌属(Pseudomonas)是各土壤样本所共有的nirS-型反硝化菌的优势菌属,但它们在每个土壤样本中的相对丰度各有差异。Alpha-Proteobacteria的根瘤菌属(Rhizobium)是盐角草各土壤样本中较为广泛存在的nirK-型反硝化细菌。艾比湖湿地盐角草各土壤样本中的反硝化细菌群落结构存在着一定的差异。RDA结果显示含水量、有机质、全氮和铵态氮等对各土壤样本中的nirS-型反硝化细菌的多样性影响较大,含水量、有机质、全氮、碱解氮等是nirK-型反硝化细菌多样性的主要影响因素。土壤电导率、全磷、全钾、全氮和碱解氮协同影响nirS-型反硝化细菌的群落结构,有机质、速效钾、速效磷、pH和硝态氮是nirK-型反硝化细菌群落结构组成的主要影响因素。艾比湖湿地反硝化细菌呈现季节性变化,nirS-型和nirK-型反硝化细菌以不同的主要菌属,共同推进湿地反硝化作用。而对于湿地生态系统的保护,则需要进行长期而广泛的土壤状态评估和土壤反硝化微生物菌群的动态监测。 Abstract:The purpose of this study is to understand the distribution and seasonal variation of different types of denitrifying bacteria in the rhizosphere and non-rhizosphere of the saline plant Salicornia europaea in the Ebinur Lake Wetland, so as to provide data support for the process of soil nitrogen cycling driven by microorganisms in the process of vegetation restoration in the Ebinur Lake Wetland, a representative of desert salinization ecosystem in temperate arid area. In this study, the rhizosphere and non-rhizosphere soil samples of Salicornia europaea were collected from the Ebinur Lake Wetland in summer, autumn and spring. The diversity and community structure characteristics of nirS-type and nirK-type denitrifying bacteria were compared and analyzed by high-throughput sequencing. RDA(redundancy analysis) was used to explore the effects of soil physical and chemical factors on the diversity and community structure of denitrifying bacteria. Among the soil samples of Salicornia europaea in the Ebinur Lake Wetland, the highest genotype diversity of denitrifying bacteria in nirS and nirK was the autumn rhizosphere, and the diversity of denitrifying bacteria in each soil sample showed rhizosphere > non-rhizosphere. The nirS-type denitrifiers in rhizosphere and non-rhizosphere soil samples of Salicornia europaea belonged to Proteobacteria, Firmicutes and Actinobacteria, while the classification of nirK-type denitrifying bacteria only includes Proteobacteria, Firmicutes. Proteobacteria accounted for a higher proportion in each soil sample. Halomonas and Pseudomonas of gamma-Proteobacteria were the dominant genera of nirS-type denitrifiers shared by all soil samples, but the relative abundance in each soil sample was different. Rhizobium of alpha-Proteobacteria was a kind of nirK-type denitrifiers widely existing in the soil samples of Salicornia europaea. There were certain differences in the community structure of denitrifying bacteria among the soil samples of Salicornia europaea in the Ebinur Lake Wetland. The results of RDA showed that water content, organic matter, total nitrogen, and ammonium nitrogen had a great influence on the diversity of nirS-type denitrifying bacteria in soil samples, while water content, organic matter, total nitrogen and alkali hydrolyzed nitrogen were the main factors affecting the diversity of nirK-type denitrifying bacteria. Soil electrical conductivity, total phosphorus, total potassium, total nitrogen and alkali-hydrolyzable nitrogen synergistically affected the community structure of nirS-type denitrifying bacteria, while organic matter, available potassium, available phosphorus, pH and nitrate nitrogen were the main influencing factors of the community structure of nirK-type denitrifying bacteria.With the change of seasons, the diversity and community structure of nirS-type and nirK-type denitrifying bacteria in rhizosphere and non-rhizosphere of Salicornia europaea were changed. The denitrifying bacteria of the two genotypes, with different main genus, jointly promoted the denitrification of wetland. For the protection of wetland ecosystems, long-term and extensive soil state assessment and dynamic monitoring of soil denitrifying microbial flora are required. 参考文献 相似文献 引证文献