广西会仙湿地不同植物根际细菌群落结构及多样性研究

Bacterial Communities Structure and Diversity in Rhizosphere of Different Plants from Huixian Wetland, Guangxi

为了研究会仙喀斯特湿地不同植物根际细菌的群落结构和多样性以及环境因子对细菌群落的影响,以秋、冬两季植物根际土壤中提取的总DNA为模板,运用Illumina HiSeq 2500高通量测序技术,对细菌16S rDNA基因V4+V5进行测序和分析。结果表明,共获得细菌有65门、160纲、219目、391科、677属和246种,不同植物根际土壤中占主导的细菌类群相同,主要包含变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)等10个主要门类细菌,其中变形菌门为第一优势菌(平均含量42.4%);优势菌纲有γ-、β-、δ-变形菌纲(Gammaproteobacteria、 Betaproteobacteria、 Deltaproteobacteria)、厌氧绳菌纲(Anaerolineae)、unidentified_Actinobacteria纲、全噬菌纲(Holophagae),以β-变形菌纲为主(平均含量为13.5%);优势菌属以地杆属(Geobacter)、芽孢杆菌属(Bacillus)、厌氧粘菌属(Anaeromyxobacter)为主,以芽孢杆菌属占比最高(占3.8%)。芦苇(Phragmites australis)多样性和丰富度最高,华克拉莎(Cladium chinense)和苦草(Vallisneria natans)次之,美人蕉(Canna indica)最低;冬季土壤细菌多样性高于秋季;美人蕉两季根际细菌群落差异最大,华克拉莎最小。环境因子对细菌群落结构有较大影响,其中土壤TOC、TN影响最显著。从植物根际微生物多样性和丰富度来看,在会仙湿地中增植芦苇和华克拉莎,对维持湿地系统中微生物多样性和湿地的保护有重要意义。

To investigate rhizosphere bacterial community structure and diversity of different plants and the influence of environmental factors on bacterial community in Huixian karst wetland,based on the total DNA extracted from the plant rhizosphere soils in autumn and winter,the V4+V5 areas of 16S rDNA gene of bacteria were sequenced and analyzed by the Illumina HiSeq 2500 high-throughput sequencing technology.The results indicated that 65 phylums,160 classes,219 orders,391 families,677 genuses and 246 species of bacteria were obtained from the rhizosphere soils of different plants.The dominant bacteria groups in the rhizosphere soils were similar,mainly including 10 main phylums such as Proteobacteria,Acidobacteria,Chloroflexi,Actinobacteria and Bacteroidetes.Among them,Proteobacteria was the first dominant bacteria with an average content of 42.4%.The major classes were Gammaproteobacteria,Betaproteobacteria,Deltaproteobacteria,Anaerolineae,unidentified_Actinobacteria,Holophagae,and in which Betaproteobacteria was the main class with an average content of 13.5%.The dominant genuses were Geobacter,Anaeromyxobacter and Bacillus(the most dominant genus,accounting for 3.8%).The bacterial diversity and richness analysis showed that Phragmites australis was the highest,followed by Cladium chinense,Vallisneria natans and Canna indica was the lowest.The bacterial community diversity in winter was higher than autumn.In comparison,the seasonal variation of bacterial communities in rhizosphere soils of Cannan indica was the greatest,but the lowest for Cladium chinense.Environmental factors have great influence on bacterial community structure and diversity,especially TOC and TN in soils.According to the diversity,richness and dominant species of plant rhizosphere,increasing the cultivation of Phragmites australis and Cladium chinense in Huixian wetland is great significance for maintaining microbial diversity and wetland protection in wetland systems.