化学农药对烤烟根际土壤细菌群落结构与功能的影响OA

To investigate the effects of chemical pesticides on the structure and function of bacterial communities in rhizosphere soil,the mature microorganisms in rhizosphere soil of tobacco variety KRK26 were studied.High throughput sequencing was used to analyze the changes in composition,structure,and function of soil bacteria after the application of Metalaxyl-M mancozeb WG.The results showed that the number of OTUs in the bacterial community of rhizosphere soils using chemical pesticides(CF)was lower than that of the control(CK)in all taxonomic units.The Chao index,Ace index,Shannon index,and Simpson index were significantly higher compared to the CK.At the phylum level,the community composition was mainly dominated by Proteobacteria and Actinobacteria,with CK and CF ac-counting for 61.84％and 71.44％respectively.The phyla Firmicutes,Gemmatimonadota,and Myxomycota show significant differences between different treatments,with CF being the most abundant in Firmicutes and CK being the most abundant in Bacteromonas and Myx-omonas.At the genus level,Sphingomonas and Streptomyces have higher abundance.Acinetobacter was found in CF treatment but not in CK.The genera Amycolatopsis and Gemmatimonas showed significant differences between different treatments,with CK being relatively more abundant.The modularity indices for bacterial communities of rhizosphere in CK and CF were 0.666 6 and 0.298 9,respectively.At the same time,the number of nodes and aggregation coefficient in CK treatment were higher than those in CF treatment.The bacterial community function involved in six primary functions such as metabolism and genetic information processing.Metabolism was the most im-portant function and the relative abundance of metabolic functions by CK and CF was 70.52％and 70.23％,respectively.Meanwhile,the bacterial community function involved in 42 secondary functions,mainly carbohydrate metabolism and amino acid metabolism.The a-bundance of carbohydrate metabolic functions by CK and CF was 15.88％and 15.64％,respectively,and the abundance of metabolic functions by amino acid was 14.92％and 14.89％,respectively,all of which were higher in CK.It could be seen that the use of chemi-cal pesticides reduced diversity and stability of microbial in soil,alters community composition,and decreased metabolic functional abun-dance.