洱海沙坪湾湖滨带不同植被带中细菌分布特征

Bacteria Distribution Characteristics of Different Vegetation Belts along Shapingwan Riparian Zone of Erhai Lake

湖滨带是湖泊保护的重要屏障,其不同植被带中的细菌对入湖污染物降解起重要作用.为研究不同植被带中的细菌分布,以洱海沙坪湾湖滨带为研究对象,采用Illumina Hi Seq高通量测序方法,对其中AG(乔草植被带)、EP(挺水植被带)、SP(沉水植被带)和UV(无植被带)的土壤或沉积物中的细菌多样性和群落结构进行研究.结果表明:湖滨带植被带中细菌种类丰富,共有54个门、106个纲、192个目、334个科和503个属被检测到,细菌的OTUs从高到低依次为EP(3 162个)、AG(2 926个)、UV(2 709个)和SP(2 427个),Shannon-Wiener多样性指数从高到低依次为EP(10.14)、AG(9.75)、SP(9.44)和UV(9.26);湖滨带植被带中主要细菌类群是变形菌门(Proteobacteria)(AG,48.55%;EP,47.83%;SP,40.36%;UV,44.00%)、酸杆菌门(Acidobacteria)(AG,19.30%;EP,5.31%;SP,5.67%;UV,6.30%)、厚壁菌门(Firmicutes)(AG,6.01%;EP,8.24%;SP,3.96%;UV,13.13%)和绿弯菌门(Chloroflexi)(AG,3.98%;EP,8.91%;SP,8.95%;UV,7.59%),主要类群在不同植被带中占比不同;植被带类型对细菌的群落结构特征影响不大,但对细菌种群的多样性影响较大.典型对应分析(CCA)结果显示,w(TP)、pH和w(OM)(OM为有机质)是影响不同植被带细菌种群结构的主要环境因子.

Abstract： The riparian zone is an important protection barrier for lakes,and the microorganisms in different vegetation belts of the zone play important roles in influent pollutant degradation.To study the bacteria distribution characteristics in different vegetation belts, Shapingwan riparian zone of Erhai Lake was selected as the study area. Illumina HiSeq high throughput sequencing molecular approach was used to study the bacteria diversity and community structure of the arbor grass vegetation belt （AG）,emergent plant belt （EP）,submerged plant belt （SP） and unvegetated belt （UV）.The results showed that the bacteria species were very abundant in different vegetation belts, and there were 54 phyla, 106 classes, 192 orders, 334 families and 503 genera.The vegetation belts with bacteria OTUs number from high to lowwere as follows：EP （3162）,AG （2926）, UV （2709） and SP（2427）, and the vegetation belts with Shannon diversity indices from high to low were EP（10.14）,AG （9.75）, SP （9.44） and UV （9.26）. The predominant bacteria community were Proteobacteria（48.55% for AG, 47.83% for EP, 40.36% for SP and 44.00% for UV）,Acidobacteria（19.30% for AG, 5.31% for EP, 5.67% for SP and 6.30% for UV）, Firmicutes（6.01% for AG, 8.24% for EP, 3.96% for SP and 13.13% for UV） and Chloroflexi（3.98% for AG, 8.91% for EP, 8.95% for SP and 7.59% for UV）, whose proportions in different vegetation belts were different. The results showed that the vegetation belt differences had influences on the bacteria diversity and community characteristics. Canonical correlation analysis indicated that TP,pH and OM were the most important environmental factors which affected the bacterial community in Shangpingwan riparian zone of Erhai Lake.