Soil microbial diversity analysis in organic vegetable field based on high-throughput sequencing

【Objective】To reveal advantages of organic planting from the perspective of microorganism and explore environmental factors affecting microbial community diversity,so as to provide a theoretical basis for establishing a reasonable planting system.【Method】Soil in 0-15 and 15-30 cm of in field with organic and conventional planting was taken as the research objects,and differences of soil microbial community structure were analyzed by using high-throughput sequencing technology. Key soil environmental factors affecting microbial community structure were identified through dbRDA analysis.【Result】Richness index and diversity index of soil microorganisms under the 2 planting methods were higher in bacteria than that in fungi. Diversity,richness and species evenness of bacterial and fungal communities in 0-15cm soil layer of organic planting were the highest and significantly different from those in other soil layers(P<0.05,the same below). Different planting methods showed that Proteobacteria in bacteria and Ascomycota in fungi were the most dominant phyla. Organic planting significantly increased the relative abundance of Actinobacteriota and Chloroflexi in bacterial community,Basidiomycota and glomeromycota in fungal community. Relative abundance of Actinomycetes in 15-30 cm soil was significantly higher than that in 0-15 cm soil,while relative abundance of the 2 fungal phyla showed no significant difference. Conventional cultivation significantly increased the relative amounts of Proteobacteria and Acidobacteriota in bacteria,Mortierellomycota,Chytridiomycota and Zoopagomycota in fungi. Organic planting could increase the number of beneficial microbial groups such as Haliangium and Mortierella in the soil. Conventional planting significantly increased the number and abundance of soil borne disease as Ralstonia and plant pathogens,for example Fusarium and Colletotrichum. dbRDA analysis revealed that effects of soil environmental factors on bacterial community was in the order of total nitrogen(TN)>total phosphorus(TP)> soil organic matter(SOM)>pH>total kalium(TK)and the effects of soil environmental factors on fungal communities were as follows:TN>TP>pH>SOM>TK. pH,SOM,TN and TP were the key factors significantly influencing soil microbial community structure.【Conclusion】Obvious differences exist in microbial communities that play key roles in different soil layers. Organic planting increases abundance of beneficial microbial communities and reduces abundance of soil borne diseases and pathogenic microorganisms. TN,SOM,TP and pH are the main driving factors affecting microbial community structure.