基于454高通量测序的黄土高原不同乔木林土壤细菌群落特征

选取黄土高原不同乔木林（辽东栎，LDL；侧柏，CB；刺槐，CH；油松，YS）表层土壤为研究对象，利用第二代高通量测序技术罗氏454平台对其进行16S rRNA基因V1~V3可变区测序，通过分析其Alpha多样性、物种组成和丰度、群落结构，结合土壤的理化性质研究其对细菌群落结构的影响.结果表明：所有土壤样品共检测到36个门，84个纲，187个目.不同乔木林土壤中优势菌来自变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、酸杆菌门（Acidobacteria）、绿弯菌（Chloroflexi）和浮霉菌门（Planctomycetes），主要的优势菌纲为放线杆菌纲（Actinobacteria）、α-变形菌纲（Alphaproteobacteria）、酸杆菌（Acidobacteria）、β-变形菌纲（Betaproteobacteria）、浮霉菌纲（Planctomycetacia）.不同乔木林土壤中绿弯菌门（Chloroflexi）与pH值呈极显著的正相关，总磷和蓝细菌（Cyanobacteria）呈极显著的正相关，微生物生物量碳与芽单胞菌门（Gemmatimonadetes）呈极显著的负相关，土壤总磷含量可能为CB样地区别于其他土样群落组成的主要因素.LDL样地细菌群落受环境影响较小.

Soil microbial communities by 454prosequencing under different arbor forests on the Loess Plateau

To determine the diversity of soil bacterial communities and its affecting factors with the method of high-throughput 454pyrosequencing technology, Soil samples were collected from four different arbor forests (Quercus liaotungensis, LDL; Biota orientalis, CB; Ptabulaeformis Carr; YS; Robinia pseucdoacacia, CH)), which represented the dominant communities for the forest vegetation ecosystem in the northwest of the Loess Plateau. The results showed that the structures of the microbial communities differed in terms of both the predominant phylum and the relative abundance of each phylum. At the phylum level, the dominant phyla were Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi and Planctomycetes. At the class level, the Actinobacteri, Alphaproteobacteria, Acidobacteria, Betaproteobacteria and Planctomycetacia were predominant. Compared with other arbor forests, the relative abundance of Acidobacteria and Bacteroidetes for LDL were the most abundant, while the relative abundance of Chloroflexi in YS and CB were more abundant than other vegetation types. Soil pH was significantly correlated with the relative abundance of Chloroflexi, and soil total phosphorus was significantly correlated with the relative abundance of Cyanobacteria, suggesting that soil total phosphorus was the main factor of affecting soil bacterial communities.