荒漠豆科灌丛根际土壤氨氧化和反硝化微生物功能基因丰度及群落多样性特征  

Functional gene abundance and community diversity of ammonia-oxidizing and denitrifying microorganisms in the rhizosphere soil of desert leguminous shrubs

作　　者：刘爽 姚佳妮 张钧杰 代金霞 LIU Shuang;YAO Jia-ni;ZHANG Jun-jie;DAI Jin-xia(College of Life Sciences,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学生命科学学院,宁夏银川750021

出　　处：《草业学报》2024年第5期115-127,共13页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(32160023);宁夏自然科学基金项目(2023AAC03062);宁夏大学研究生创新项目(CXXM2022-13)资助。

摘　　要：为探索宁夏荒漠草原豆科灌丛根际土壤中参与氨氧化和反硝化的微生物功能基因丰度和群落组成对植物类型和生长时期的响应特征,本研究以宁夏白芨滩国家级自然保护区内典型的豆科灌丛群落柠条、沙冬青、猫头刺和毛刺不同生长时期(营养期、盛花期和果实期)的根际土壤为材料,通过功能基因实时荧光定量PCR和高通量测序方法,分析4种灌丛根际土壤中氨氧化和反硝化微生物功能基因丰度、群落结构组成特征及其与土壤因子的相关性。结果表明,功能基因丰度及群落结构因灌丛类型和生长时期不同而存在差异。柠条灌丛根际土壤中各功能基因丰度显著高于其他3种灌丛,且在盛花期达到最高。柠条各生长期根际土壤中氨氧化细菌(ammonia-oxidizing bacteria,AOB)群落多样性高于其他灌丛类型,而毛刺根际氨氧化古菌(ammonia-oxidizing archaea,AOA)和nirK型反硝化菌群落多样性最低。各灌丛根际AOA以未分类类群为绝对优势,占79.34%~98.37%,奇古菌门和泉古菌门分别仅占0.28%~20.37%和0.28%~2.35%;AOB在柠条根际以变形菌门为优势,其他3种植物根际则以未分类类群为优势;nirK和nirS型反硝化菌均以变形菌门为优势门,但nirK型反硝化菌的组成受植物类型和生长时期的影响更显著。功能基因的丰度与土壤全氮、速效钾和pH显著正相关。全钾、速效钾、有机质显著影响氨氧化微生物的群落组成,pH是反硝化微生物群落结构的主要影响因子。The aim of this study was to explore the patterns of functional gene abundance and community composition of microorganisms involved in ammonia oxidation and denitrification in rhizosphere soil of leguminous shrubs on the Ningxia desert steppe among different plant types and growth periods.We collected rhizosphere soil samples from typical leguminous shrub communities in the Baijitan National Nature Reserve of Ningxia,including Caragana korshinskii,Ammopiptanthus mongolicus,Oxytropis aciphylla,and Caragana tibetica at different growth stages(vegetative,flowering,and fruiting stages).Using real-time quantitative PCR and high-throughput sequencing methods,the abundance of functional genes and the characteristics of community structure of ammonia-oxidizing and denitrifying microorganisms in rhizosphere soil of four shrubs,as well as their correlations with soil factors,were analyzed.It was found that the abundance of functional genes and community structure varied among different shrub types and growth periods.The abundance of functional genes was significantly higher in the rhizosphere soil of C.korshinskii than in the rhizosphere soil of the other shrubs,and reached the highest level during the flowering period.The diversity of the ammonia-oxidizing bacteria(AOB)community in the rhizosphere soil of C.korshinskii at different growth periods was higher than that of the AOB communities in the rhizosphere soils of the other shrub types,while the diversity of ammonia-oxidizing archaea(AOA)and nirK-type denitrifying bacteria communities was lowest in the rhizosphere soil of C.tibetica.Unclassified taxa were the predominant AOA in rhizosphere soil of each shrub with an extremely high abundance of 79.34%-98.37%,whereas Thaumarchaeota and Crenarchaeota only accounted for 0.28%-20.37%and 0.28%-2.35%,respectively.Proteobacteria was the dominant phylum of AOB in the rhizosphere of C.korshinskii,while Norank_d__Bacteria was the dominant AOB in the rhizosphere soil of the other plants.Both nirK-and nirS-type denitrifying bacteri

关 键 词：固沙灌丛 氨氧化 反硝化 功能基因 群落组成 多样性 

分 类 号：S812.2[农业科学—草业科学]