Study On Microbial Community Structure And Functional Diversity Of Betula Platyphylla Rhizosphere Soil In Inner Mongolia

In this paper,the root soil of Betula platyphylla in Inner Mongolia was taken as the research object.The sampling points from west to East were Helanshan National Nature Reserve,Erlongshitai National Forest Park,HADAMEN National Forest Park,Wulanba forest farm and Daxinganling ecological positioning station.The 16 S rDNA of bacteria was sequenced by high-throughput sequencing platform of Illumina miseq The high-throughput sequencing of v3-v4 region and ITS1 region of fungi was carried out respectively,and the microbial diversity and community structure of Betula platyphylla rhizosphere soil were analyzed.The response of microbial community structure to the change of environmental factors was studied by comparing pH,AP,TN,OM,AK,AN,NN and WC of soil physical and chemical properties.The species,diversity and community structure of soil microbe around birch root are clear,and the species diversity and metabolic function diversity of soil microbe are revealed,which is of great significance to further understand the structure and function of underground ecosystem and to carry out the protection and utilization of microbial diversity resources.The main results are as follows:(1)A total of 26,371 OTUs were obtained from the bacteria in the roots of Betula platyphylla in 5 plots,which belonged to 39 phylum,147 classes,446 orders,800 families,and 1406 genera.Bacteria on the roots of birch roots at the phylum level(relative abundance greater than 1%),mainly distributed in Proteobacteria,Acidobacteria,Actinobacteria,Actolobacteria,Chloroflexi,Bacteroidetes,Dental List Gemmatimonadetes,Verrucomicrobia,Latescibacteria,Rokubacteria and Nitrospirae;at the genus level(relativeabundance greater than 1%),RB41,Candidatus Udaeobacter,Ellin6067,Gaiella,Sphingomonas Genus Sphingomonas,MND1,Bradyrhizobium Bradyrhizobium,Rhodoplanes,Nitrospira,Candidatus Solibacter,Ochrobactrum,Vibrionimonas,Haliangium,Granulicella,Acidothermus,Mucilaginibacter,Mycelibacter,Roseiarcus,and Bryobacter 18 of the genus bacterias.(2)A total of 4267 OTUs were obtained from the root fungus soil of Betula platyphylla in five plots,which belonged to 555 genera of 14 phylums,53 classes,125 orders,276 families.At the level of the fungal phylum of birch roots(relative abundance greater than 1%),mainly distributed in Ascomycota,Basidiomycota,and Mortierellomycota;the genus level(relative abundance greater than 1%)is Alternaria,Archaeorhizomyces,Aspergillus,Aureobasidium,Cladosporium,Fusarium,Gibberella,Hygrocybe,Ilyonectria,Lophiostoma,Mortierella,Mycena,Nigrospora,Penicillium,Serendipita,Solicoccozyma and Tetracladium.In addition,it also includes 13 kinds of ectomycorrhizal fungi,namely Clavulina,Clavulinopsis,Cortinarius,Hygrophorus,Inocybe,Piloderma,Russula,Sebacina,Tomentella,Tricholoma,Amanita,Helvellosebacina and Cenococcum.(3)Analysis of the bacterial ?-diversity of Betula platyphylla root soil showed that the bacteria richness and diversity in Betula platyphylla root soil of Erlong Shitai National Forest Park were the largest and diversity distributed in Helan Mountain National Nature Reserve.The Daxing'anling Ecological Positioning Station has the least abundance and diversity,and the species distribution is uneven.The results of ? diversity show that,the bacterial community composition of Erlong Shitai National Forest Park,Hadamen National Forest Park and Helan Mountain National Nature Reserve were relatively similar,but the bacterial community composition of Daxinganling Ecological Positioning Station and Wulanba Forest Farm were quite different.(4)Analysis of fungal ?-diversity in Betula platyphylla soils showed that the Betula platyphylla soils in Helan Mountain National Nature Reserve hadthe largest species diversity and richness,and were more Uniform distribution,while the Betula platyphylla soils abundance and diversity in Daxinganling monitoring station were the smallest and distributed Uneven.The results of ?diversity indicate that the composition of fungal communities in Erlong Shitai National Forest Park,Hadamensenling Park,Helan Mountain National Nature Reserve and Wulanba Forest Farm is more similar,and the composition of the fungal community in Daxinganling Ecological Positioning Station is quite different.(5)Analysis of microbial community combined with soil physical and chemical factors showed that bacterial community diversity was significantly negatively correlated with water content;fungal diversity was extremely significantly positively correlated with available potassium and nitrate nitrogen,and extremely positive with soil total nitrogen and ammonium nitrogen Significantly negative correlation.The results of redundant analysis and correlation analysis on the physical and chemical properties of the soil showed that the physical and chemical properties of the soil have a significant effect on the composition of the microbial community in the root circumference of Betula platyphylla,and the degree of influence on the dominant genera of bacteria were: WC> OM> AP> AK> TN > AN > NN> pH;the order of influence on the dominant genus of fungi is: NN> AK>pH> WC> AP> OM> AN> TN;the order of influence on the dominant genus of ectomycorrhizal fungi is: TN> AN> OM> AP> WC> pH> AK> NN.(6)Microbial metabolism of Betula platyphylla rhizosphere soil was discovered that from the perspective of the diversity of microbial metabolic functions in the root soil,the species richness,dominance and uniformity of the microbial community in the Daxinganling Ecological Positioning Station showed consistent differences,significantly lower than the other four plots,indicating that the metabolic function diversity of the microbial community in the Daxinganling Ecological Positioning Station is the lowest.There is no significant difference in the abundance an uniformity among the other four plots,all expressed as: Erlong Shitai National Forest Park> HadamenNational Forest Park> Helan Mountain National Nature Reserve>Wulanba Forest Farm.The carbon source utilization capacity in the five plots shows that the size of the carbon source utilization varies in different ways,but the main sources are carbon and nitrogen.