【摘要】 微生物是土壤元素生物地球化学循环的主要驱动力,目前库滨带植物截留和消减污染物质过程中细菌群落及其功能研究尚未清楚.本研究选取适宜丹江口库区库滨带生长的4种典型植物(草本植物香根草、芦苇、乔木植物杜梨和灌木植物假奓包叶),采用16S r DNA Miseq高通量测序技术研究根际细菌群落组成,发现其主要由变形菌门、拟杆菌门、放线菌门等31个门、343个属的细菌组成,表现出群落组成的丰富性.细菌群落分析表明香根草和芦苇细菌群落结构较为相似,但和杜梨细菌群落结构差异最大.PICRUSt功能预测分析表明,库滨带植物根际细菌主要涉及次生产物代谢的生物合成、转录、多糖生物合成和代谢、细胞生长和死亡等38个子功能,表现出功能上的丰富性.库滨带植物根际细菌代谢能力整体趋势为假奓包叶>芦苇>香根草>杜梨.本研究初步探讨了丹江口库区库滨带不同植物根际细菌群落和功能,为丹江口水库库滨带植被构建及其水环境保护提供了参考依据.更多还原

【Abstract】 Microbial communities play crucial roles in the global biogeochemical nitrogen cycle.To our knowledge,the compositions and functions of rhizosphere communities in riparian buffer strips have not been reported.In this study,rhizosphere soil samples were collected from herbs(Vetiveria zizanioides and Phragmites australis),trees(Pyrus betulifolia),and shrubs(Discocleidion rufescens) in the Danjiangkou Reservoir in June 2017.High-throughput sequencing was performed to analyze the community structure and diversity of bacteria.Phylogenetic analysis based on 16 S r DNA sequences shows that the bacterial communities can be divided into 31 major phylogenetic groups.The dominant phylogenetic groups include Proteobacteria,Bacteroidetes,Actinobacteria,Gemmatimonadetes,and Acidobacteria.Phylogenetic investigation of communities by reconstruction of unobserved states(PICRUSt) was used to determine the metabolic and functional abilities of the observed bacterial communities.Our results reveal a wide genetic diversity of organisms involved in various essential processes such as biosynthesis of other secondary metabolites,transcription,Glycan biosynthesis and metabolism,cell growth and death,and carbohydrate metabolism.Based on the 16 S rRNA gene copy number of the detected phylotype,the bacterial rhizospheres of plants in riparian buffer strips can be ranked as follows:Discocleidion rufescens > Phragmites australis > Vetiveria zizanioides > Pyrus betulifolia.We analyzed the differences of different plants from the perspective of bacterial community composition and function and provide a foundation for vegetation construction and water environmental protection in riparian buffer strips of the Danjiangkou Reservoir.更多还原