施用生物有机肥对烟草根际土壤微生物区系的影响

Effects of bio-organic fertilizer on the microflora in plant rhizosphere soil and bacterial wilt control of tobacco

为研究生物有机肥对烟草青枯病的防控效果及对烟株根际土壤微生物区系的影响,采用拮抗菌复配菌剂添加至有机肥制成生物有机肥,施于烟田,分别在烟株不同生长时期采集根际土壤进行可培养微生物测定及16 S/18 S rDNA基因测序,探究烟株根际土壤微生物区系的变化及其对青枯病发病率、烟叶产量与品质的影响。结果表明,施加生物有机肥的处理组对烟草青枯病的防控率达到了38.2%,烟叶产量提高8.6%。基因测序结果显示,旺长期根际土壤中变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)在处理组中的丰度与对照组相比分别降低了32.1%,48.7%,绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)分别增加了55.3%,54.6%,各物种多样性指数均为处理组显著高于对照组。在大田中施用生物有机肥能明显改善烟株根际土壤的微生物区系结构,提高生物多样性、增加群落丰富度,对青枯病具有较好的防控效果。旺长期为烟株根际微生物区系变化的关键时期,该时期处理组与对照组之间在群落结构及有益菌上的显著差异可能会影响青枯病的发生。

This paper aimed to study the effect of bi-organic fertilizer on the control of tobacco bacterial wilt and the microbial flora of tobacco rhizosphere soil.The biological organic fertilizer was prepared by adding antagonistic antibacterial compound bacterial agent to organic fertilizer and applied to the toba-cco fields.In order to explore the changes of rhizosphere microbial flora of tobacco plants and its influence on the incidence of bacterial wilt from the treated soil,the yield and quality of tobacco leaves,tobacco rhizosphere soil was collected at different growth periods of plants for culturable microorganism determination and 16S/18S rDNA gene sequencing.The results showed that the control rate of tobacco bacterial wilt could reach to 38.2%and the tobacco yield was increased by 8.6%in bio-organic fertili-zer treatment.Compared with the control group,gene sequencing results showed that the abundance of Proteobacteria and Firmicutes in soil rhizosphere decreased by 32.1%and 48.7%in the treatment group during the vigorous growth stage,while the Chloroflexi and Acidobacteria increased by 55.3%and 54.6%,respectively.All the species diversity indexes in the treatment were significantly higher than those in the control group.Application of bio-organic fertilizer in the field could not only significantly improve the microbial flora structure of soil rhizosphere of tobacco,biological diversity,and community richness,but also had a better control effect on bacterial wilt.It may affect the occurrence of bacterial wilt due to the significant differences in community structure and beneficial bacteria between the treatment group and the control group during this period.