大豆和玉米茬口对冬小麦根际土壤细菌群落结构和功能的影响OA北大核心CSTPCD

To explore the differences in the effects of maize stubble and soybean stubble in the Huang-Huai-Hai area,in 2023,rhizosphere soil samples at the jointing stage of winter wheat were collected under the conditions of long-term positioning test fields for up to 4 years(2019-2023).The responses of rhizosphere soil bacterial community structure and function to no nitrogen application(N0)and conventional nitrogen application(N240,pure nitrogen 240 kg/ha)were studied by using 16S high-throughput sequencing technology combined with Tax4Fun2 function prediction analysis in the jointing stage of winter wheat under maize(M)stubble and soybean(S)stubble,respectively.There were four treatments(MN0,SN0,MN240,SN240)in total.The results showed that,at the phylum level,Proteobacteria,Acidobacteria,Bacteroidetes and Actinobacteriota were the dominant rhizosphere bacteria of winter wheat with a relative abundance of 66.66%—69.56%.Under N0 nitrogen application rate,the relative abundance of Bacteroidetes in S stubble was significantly increased by 19.10%compared with that in M stubble(P<0.05),and under N240 nitrogen application rate,the relative abundance of Proteobacteria in S stubble was significantly increased by 11.90%compared with that in M stubble(P<0.05).At the order level,Vicinamibacterales and Burkholderiales were the dominant bacteria with a relative abundance of 18.42%—19.68%.Under N0 nitrogen application rate,the relative abundance of Vicinamibacterales in S stubble was significantly reduced by 13.69%compared with that in M stubble(P<0.05);The relative abundance of Burkholderiales was increased significantly by 11.31%(P<0.05).Through the Tax4Fun2 function prediction and the KEGG data comparison,it was found that there were significant differences in the relative abundance of seven functional pathways under the metabolism category under N0 nitrogen application rate(P<0.05),and correlation analysis further revealed that there was a significant correlation between Vicinamibacterales and Burkholderiales and amino acid metabolism pathways(P<0.01).There were 26 functional genes involved in soil nitrogen cycling pathway in winter wheat soil bacteria,and the relative abundance of denitrification functional genes accounted for the largest proportion.Under N0 nitrogen application rate,the relative abundance of denitrification functional genes norB,norC and nirS in M stubble was significantly higher than that in S stubble(P<0.05).In conclusion,the stubble causes the soil bacterial community structure of winter wheat to change under different amount of nitrogen.Different stubble affects the nitrogen metabolism function of bacterial community by changing the structure of rhizosphere soil bacterial community.