Effects Of Different Control Measures On Rhizosphere Soil Microflora Of Tobacco In Fujian Province

The investigation of tobacco cultivation and disease incidence in shaowu tobacco region of fujian province showed that tobacco bacterial wilt was the main disease affecting the quality of tobacco production.In order to reduce the incidence of tobacco bacterial wilt,improve tobacco leaf production,this article through to the fujian province shao-wu vega disease take different measures,respectively before transplanting of tobacco plant,collecting pellets tree period,vigorous,maturity of rhizosphere soil,soil physical and chemical properties,high-throughput gene sequencing,and determine the incidence of tobacco plant and economic characters of flue-cured tobacco in mature.To study its effect on the structure and pathogenesis of rhizosphere soil microbial flora.It provides theoretical support for improving soil health and preventing and controlling bacterial wilt in tobacco field.The test results are as follows:(1)The results of applying bio-organic fertilizer show that the control rate of tobacco bacterial wilt in the treatment group treated with bio-organic fertilizer reached 38.2%,and the tobacco yield increased by 8.6%.The gene sequencing results showed that the abundance of Proteobacteria and Firmictes in the rhizosphere soil during the flourishing period decreased by 32.1 % and 48.7 %,respectively,and that Chloroflexi and Acidobacteria increased by 55.3 % and 54.6 %,respectively,compared with the control group.The species diversity index of the treatment group was significantly higher than that of the control group.Application of bio-organic fertilizer in the field can significantly improve the microbial flora structure of the rhizosphere soil of tobacco plant,improve the biodiversity and increase the community richness,and have a better prevention and control effect on bacterial wilt.The growth period is the critical period for the change of rhizosphere microflora of tobacco plants,during which the significant differences in community structure and beneficial bacteria between treatment group and control group may affect the occurrence of bacterial wilt.(2)The results of application of lime nitrogen indicate that the relative abundance of Nitrospirae and Basidiomycota increased by 55.0% and 105.6%,while that of Ascomycota decreased by 20.2%,and the Sobs index,Shannon index and Chao index increased by 6.3%,3.1% and 3.4%,respectively.PCA analysis showed that the structure of the rhizosphere soil microbial flora under the application of lime nitrogen was different from that of the control soil from the cluster stage,and the difference gradually increased with the growth of tobacco plants.The analysis of species differences showed that the abundance of Sphingomonas,Nitrospira,Flavisolibacte and other functional bacteria related to soil nitrogen cycle increased significantly in the treatment with lime nitrogen application.Statistics on the incidence of bacterial wilt and tobacco yield in the mature period showed that the prevention and control rate of tobacco bacterial wilt by applying lime nitrogen treatment reached 49.9%,and the tobacco yield increased by 11.7%.(3)The results of compound application of lime nitrogen and biological fertilizer show that the relative abundance of Nitrospira in the rhizosphere soil of tobacco cluster treated with lime nitrogen increased,while the relative abundance of Saccharibacteria decreased significantly.PCA analysis showed that the structure of rhizosphere soil microbial flora was significantly different from that of the control group in the treatment with lime nitrogen and biological bacteria agent after the tobacco plant grew into flourishing period.At the maturity stage of tobacco plant growth,Sobs index of T2 and T3 treated with lime nitrogen and biological bacteria agent increased by 6.5% and 4.6%,Shannon index increased by 2.9% and 2.4%,and Ace index increased by 5.7% and 7.3%,respectively,compared with the control group.The pathogen abundance of T2 and T3 treated during this period decreased by53% and 70% respectively compared with the control group.The statistical results of the incidence of bacterial wilt showed that the prevention and control rates of tobacco bacterial wilt were 45.3% and 58.8%,respectively.(4)The results of tobacco rice rotation showed that the relative abundance of Chloroflexi,Acidobacteria and Nitrospirae increased by 21.5%,94.8% and 80.4%,Sobs,Shannon and Chao index increased by 13.3%,4.0% and 15.5%,and the number of bacterial bacterial pathogens in soil decreased significantly.After tobacco planting,the microbial diversity in the soil decreased,the contents of bacterial bacterial pathogens increased,and the Acidobacteria,Bacteroidetes,Nitrospirae and other functional bacteria related to the soil carbon and nitrogen cycle significantly decreased.The results of 3 years' investigation showed that tobacco leaf bacterial wilt incidence rate decreased by 41.7% on average compared with tobacco continuous cropping.