Study On The Diversity Of Cultivated Soil Strains Based On High-throughput Sequencing

Soil microorganism is a huge community and an important part of the natural element cycle.There are many kinds and complex structures of soil microorganisms,but the culturable microorganisms only account for 1%-10%,which can not reflect the community structure of soil microorganisms.Soil microbiome is a general term for all microorganisms in soil and their habitats.The research content of soil microbiome is the co evolution rule of soil microbiome and its environmental function.At present,the most popular high-throughput sequencing of Illumina miseq is the most effective frontier technology in soil microbiome research.It can sequence the 16 S r DNA,18 S r DNA and ITS sequences of all microorganisms in the soil,detect the dominant species,rare species and unknown species in the soil,analyze the relative abundance of each species and the composition of microbial community,so as to know the changes of soil microorganisms.This paper analyzes the diversity of soil microorganisms in greenhouses and fields by collecting 97 agricultural soils from 59 different regions of Hebei Province and 32 soil samples from the long-term nitrogen fertilizer positioning test field of Hebei Academy of Agricultural Sciences,using the Illumina Mi Seq high-throughput sequencing platform,Analyzed the diversity of microbes applied to soil by nitrogen fertilizer.The results are as follows:In this paper,the soil microbiome of agricultural soils in different areas of Hebei Province was studied by using Illumina miseq high-throughput sequencing platform,and the data of culturable and non culturable microorganisms were analyzed comprehensively.The information of species composition and relative abundance in the two groups of samples were obtained,and the conclusion was that there were some differences in soil microorganism between greenhouse and field in different areas of Hebei Province.The results showed that in the soil samples of the greenhouse(M1)and the field(N1),the composition of the dominant flora was basically the same.At the level of the phylum,there were 7 kinds of bacteria,including Proteobacteria,Actinobacteria,Acidobacteria,Bacteroidetes,Chloroflexi,Firmicutes and Gemmatimonadetes.The relative abundance of actinomycetes in the field was 7%,and that of phylum sclerenchyma in the greenhouse was 2.8%.At the class level,there are 15 dominant groups,such as Alphaproteobacteria,Acidobacteria,Gammaproteobacteria,Actinobacteria,Deltaproteobacteria,Betaproteobacteria,Gemmatimonadetes,Cytophagia.Among which the relative abundances in the greenhouse are obviously increased,such as Cytophagia,Bacilli and Flavobacteriia,while the relative abundances are significantly decreased,such as Acidobacteri and Betaproteobacteria.At the genus level,there are 6 dominant groups,including Arthrobacter,Sphingomonas,Devosia,Bacillus,Xanthomonas and Lysobacter,among which Arthrobacter are more in the field,while Bacillus,Xanthomonas and Lysobacter are more in the greenhouse.In addition,the relative abundance of some bacteria groups with the ability of nitrogen fixation and degradation repair is higher in the field.This should be caused by the different planting environment between the field and the shed.In addition,by sampling from the long-term nitrogen fertilizer positioning test field of Hebei Academy of Agricultural Sciences,the differences in soil microbial community composition between rhizosphere and non-rhizosphere and the effects of long-term nitrogen fertilizer application on soil microorganisms were analyzed.The conclusion is that the dominant bacteria in the rhizosphere soil are: Bacteroidetes,Actinobacteria,Firmicutes,and the non-rhizosphere soils are: Acidobacteria,Gemmatimonadetes and Chloroflexi.From the perspective of genus level,there are 25 species of fungi with the greatest difference in rhizosphere and non-rhizosphere soils,among which more in rhizosphere are 18 species,Rhizopus,Rhodococcus,Pseudobacterium,Duganella,Cellulosi,Folium,Mycobacterium,Aspergillus,Rhizobia,Nocardia-like,Chryseobacterium,Pseudomonas,Pseudomonas,Aeromonas,Nitrobacter,Bacillus,etc.Seven species are more in non-rhizosphere,such as Bacillus,Gp4,unknown genus,Povalibacter,Thioprofundom,Pseudenhygromyxa and Rubrivirga.These 18 species of fungi in the rhizosphere soil may be because the plants need the assistance of these flora during the growing period,so they will gather towards the roots during the growing period of the plant.The effect of long-term nitrogen fertilizer application on the composition of soil microbial communities is that,in general,the relatively abundant abundance of bacteria in the whole nitrogen group is in the Bacteroidetes and Solirubrobacterales,while the dominant bacteria in the group without nitrogen fertilizer is Rhodobacteraceae.Specifically analyze the distribution of the different genus communities between the two groups at the genus level.Among all the genera that differed between the non-nitrogen-added fertilizer group and the total nitrogen group,23 species had significant differences in abundance.Among them,13 species of genus increased significantly in the group without nitrogen fertilizer,and the abundance of 10 species in the total nitrogen group increased significantly.Among these 23 types of bacteria,Candidatus Brocadia,Nitrospira,Nitrosomonas,Novosphingobium are four fungi that are related to soil nitrogen cycle.Some other genera are related to cellulose degradation and pesticide degradation.This difference is related to the amount of nitrogen fertilizer applied.The above research results provide important theoretical basis and data guidance for the scientific cultivation and rational fertilization of agriculture in the future,and have important significance for agricultural production.