生物炭用量对烟草青枯病及土壤细菌群落的影响OA北大核心CSTPCD

In order to investigate the effects of biochar dosage on tobacco bacterial wilt and rhizosphere soil community structure and function,five biochar-soil ratio of 0,1.5%,3.0%,4.5%and 6.0%(recorded as TS0,TS15,TS30,TS45 and TS60)were set in tobacco disease nursery to study the incidence of bacterial wilt of flue-cured tobacco,soil agrochemical characteristics,bacterial community structure and function.The results showed that biochar could effectively reduce the incidence of tobacco bacterial wilt,and the best effect existed in the 3.0%biochar-soil ratio.Biochar significantly increased soil pH value and organic matter,and improve soil nutrient ratio.The results of RDA analysis showed that soil pH value and soil nutrients were important factors affecting tobacco bacterial wilt,and increasing soil pH value and nutrient content could effectively reduce the incidence of bacterial wilt.Further analysis showed that biochar could increase the diversity of soil bacterial Alpha,when the biochar-soil ratio was 1.5%to 6.0%,the richness was 8.24%to 26.50%higher than that of the control.Compared with the control,the abundance of Proteobacteria increased by 2.28,9.70,5.40 and 5.28 percentage points,respectively,while the abundance of Acidobacteria decreased by 5.48,7.05,8.09 and 7.06 percentage points,respectively.Phenotypic prediction results showed that biochar could reduce the abundance of potential pathogens by increasing the abundance of Proteobacteria and decreasing the abundance of Acidobacteria.Compared with the control,the abundance with 3.0%biochar-soil ratio increased by 5.77,0.24 and 0.36 percentage points for Bacillus,Sphingosphinomonas and Sphinomonas,respectively,and decreased by 1.70 percentage points for Bacillus,and the abundance of Raleella gradually decreased with the increase of biochar application rate.In addition,biochar could improve the abundance of soil amino acid metabolism,cell growth and death function groups.Meanwhile,soil pH value,organic matter,available potassium and total element content had positive effects on amino acid metabolism,cell growth and death function,but Bacillus rotobacter had negative effects on them.In conclusion,biochar application significantly improved the proportion of soil nutrients,then changed the structure and functional characteristics of soil bacterial community,stimulated amino acid metabolism of bacterial community and other functions,improved the disease resistance of tobacco,and reduced the incidence of bacterial wilt.In this study,the biochar-soil ratio of 3.0%-4.5%was more effective in controlling bacterial wilt of tobacco plants.This study provides scientific basis for disease control and soil improvement in tobacco cultivation.