Research Of Soil Microbial Community Structure Based On High-throughput Sequencing Technology

Soil microorganism is an important part of terrestrial ecosystem, and the maincomposition of soil, it plays an important role in the formation and development ofsoil, organic matter decomposition, material and energy transmission, the earthbiochemical circulation and bioremediation, etc. Soil microorganism on the role ofthe environment that is the function diversity of the microbial is mainly by the wayof a variety of metabolic and physiological functions, so the diversity of microbialcan be known as the important instructions of evalulating the soil changes caused bythe natural or man-made interference factors. Due to the microbial effect onecosystem so obvious, so there is far significance on the soil microorganisms ofsaline-alkali soil of the Yellow River delta. In recent years, the vulnerability ofYellow River delta wetland ecosystem gets the attention of many researchers. Soilmicroorganisms can improve the stability of the wetland ecosystem, the distributionregularity of regional and saline vegetation succession of its response law is ahotspot of research in recent years, the Yellow River delta wetland has become animportant part in research on soil microbial community structure.In this research, we selectively investigated a typical wetland plant communityzone in the Yellow River Estuary Nature Reserve, which can represent the vegetationprimary succession process in the Yellow River Delta. To the distance of coastline,the order is bare land, Suaeda salsacommunity, Tamarix chinensis community,Aeluropus sinensis community, Apocynum venetum community, Imperatacylindrical community, cotton community. By determining the contents of water,salt, active organic matter, effective phosphorus, humus, available nitrogen andcatatase, urease in the soil, we studied the changing patterns of soil physicochemicalproperties at0-20cm soil depths during the vegetation succession process. Using the high-throughput sequencing technologies to sequence the soil underdifferent vegetation on the Yellow River delta wetland, getting different organisms inthe soil microorganisms from the phylum, class, order, family and genus in thebacterial community composition. All30874sequences belong to17door of bacteria,the main phylum includes Proteobacteria, Bacteroidetes, Actinobacteria,Plantomyctes, Fimicutes, Acidobacteria, Chloroflexi, Verrucomicrobia, therespectively proportion are44.67%,7.05%,9.2%,2.16%,2.15%,6.36%,1.70%,1.07%. These soil microorganisms from the phylum which belongs to Proteobacteria,Bacteroidetes, Actinobacteria and Acidobacteria phylum accounted for67.28of thetotal sequence, these soil microorganisms are strains for advantage, among of themProteobacteria is main strains for advantage. This suggested that even though thesampling sites are different, but in the same habitat in the similarity of microbialgroups. Different stages of vegetationg types, however, the main soil microbialcommunity structure is obviously different.By studying the influence of different succession of vegetation on soil microbialstructure, know that the relative abundance of Proteobacteria, Actinobacteria andAcidobacteria has significant difference, of them Proteobacteria is dominant. Underthe double salt stress, the relative abundance of Chloroflexi, Bacteroidetes andAcidobacteria has significant difference. Under the light salt stress, the relativeabundance of Proteobacteria, Chloroflexi, Bacteroidetes and Acidobacteria hassignificant difference. Under cultivation, the relative abundance of Proteobacteriaand Bacteroidetes has a downturn than that under the succession of vegetation, inaddition to salt content,there are other factors that will affect the communitystructure of the soil microorganisms. Using method to calculate the soil microbialbiodiversity index. The result is that the bacterial diversity is relative to a minimumin the bare land soil. The bacterial diversity has a tendency to increase as thecoverage of vegetation. Through the study the influence that the physical andchemical properties on the relative abundance of soil microorganisms and microbialdiversity index, can conlcud that in addition to the electrical conductivity, urease activity and soil humus are the main factors that influenced the relative abundance ofsoil microorganisms and microbial diversity index.