Characteristics Of Soil Microbial Community In Tobacco Field Of Liangshan Prefecture And Its Correlation With Environmental Factors

This study focused on the rhizosphere soils of healthy and susceptible tobacco fields in Mianning,Dechang,Huili,and Huidong counties of Liangshan Prefecture.We used high-throughput sequencing technology to compare the changes,diversity and community characteristics of soil microorganisms in different growth periods between healthy and susceptible tobacco fields,and to explore the key factors affecting the differences of rhizosphere soil microbial communities in healthy and susceptible tobacco fields,so as to provide a theoretical basis for the use of green control technology to prevent and control soil-borne diseases and improve soil quality.The results are as follows:(1)Compared with the susceptible tobacco field,the healthy tobacco field has a good function of self-regulation of soil microbial community,that is,with the growth of tobacco plants,the number of potentially pathogenic bacteria norank?o?Sordariales?norank?o?Hypocreales and Boeremia decreased significantly.(2)(1)The results showed that the diversity of soil microorganisms in Dechang,Huili and Huidong tobacco fields was higher than that in susceptible tobacco fields,while that in Mianning was significantly higher than that in healthy tobacco fields.(2)There are differences in soil bacteria between healthy and susceptible tobacco fields in different tobacco areas.Micrococcales,Xanthomonadales,norank?p?Saccharibacteria,Chloroflexi,norank?o?Sordariales,and norank?o?Hypocreales were the different bacteria in the soil of healthy and susceptible tobacco fields in Mianning County;Gammaproteobacteria,Xanthomonadaceae,norank?p?Saccharibacteria,Bacillus,Nocardioidaceae,and norank?o?Sordariales were the different bacteria in tobacco field of Dechang County;Terrabacter,Gemmatimonadetes,Tremellales,Hypocreales,and Fusarium were the difference of tobacco field in Huili County;Gaiellales,Micromonosporaceae,Trichocomaceae,Didymellaceae,Boeremia,and Fusarium were the different fungi in Huidong tobacco field.(3)Gammaproteobacteria,Xanthomonadales,Microbacteriaceae,Sphingobacteriaceae,and Sordariomycetes were the main microorganisms of healthy and susceptible tobacco fields in Liangshan Prefecture.(3)The relationship between soil environmental factors and the microbial community was significantly different in different tobacco areas.(1)There was a significant positive correlation between bacterial diversity and p H,organic matter,total phosphorus and acid phosphatase,and a significant negative correlation between fungal diversity and total potassium;there was a significant negative correlation between soil bacterial diversity and water content,total phosphorus,alkaline nitrogen and urease in Dechang tobacco field;there was a significant positive correlation between soil bacterial diversity and total phosphorus,alkaline nitrogen,and available potassium,a significant negative correlation with catalase in Huili County;there was a significant positive correlation between rhizosphere bacterial diversity and water content,and a significant positive correlation between urease and protease in Huidong tobacco field.(2)In the Mianning tobacco field,norank?o?Hypocreales and norank?p?Ascomycota were positively correlated with water content.There was a significant positive correlation between Nocardioides and organic matter in the Dechang tobacco field.In the Huili tobacco field,norank?o?Hypocreales was negatively correlated with organic matter,alkaline nitrogen and available potassium.Boeremia and Fusarium were negatively correlated with available potassium in the Huidong tobacco field.(3)Soil p H,organic matter,total potassium,available potassium,catalase,protease,and available phosphorus are the important factors that cause the differences between healthy and susceptible tobacco communities in Liangshan Prefecture.In conclusion,there were significant differences between the rhizosphere soil microorganisms of healthy and susceptible tobacco fields,and the soil environmental factors are closely related to the microorganisms.In the future work of tobacco soil-borne disease control,we should pay close attention to the change of soil properties,and improve the resistance of tobacco plants by adjusting the soil environment to affect the microbial population.