烟蒜轮作对烟株根际土壤细菌群落结构的影响

Effects of Tobacco Garlic Crop Rotation on Bacterial Community Structure of Tobacco Rhizosphere Soil

【目的】本文研究了烟蒜轮作对烟田土壤细菌群落结构及其多样性的影响。【方法】利用高通量测序技术检测土壤微生物,比较烟蒜轮作与健康烟田根际土壤细菌。【结果】凉山州德昌县试验烟田土壤优势细菌门依次为变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、绿弯菌门(Chloroflexi)、厚壁菌门(Firmicutes)和酸杆菌门(Acidobacteria),相对含量占总菌的83.31%~88.98%。移栽前,种植大蒜的易感病烟田优势细菌相对含量高于健康烟田,细菌多样性也比健康烟田高。种上烟后,易感病烟田的厚壁菌门数量显著增加,这与养分的变化一致,二者极显著正相关,厚壁菌门和芽孢杆菌都比健康烟田高,且达到了显著性差异。生长期细菌多样性比移栽前降低,易感病烟田低于健康烟田,到成熟期上升并高于健康烟田。【结论】种植大蒜提高了烟田土壤细菌群落结构的调节能力,使发病率由往年的50%降低到6.5%。可见烟蒜轮作可以调整土壤细菌群落结构趋于健康烟田,从而降低土传病害的发生。

【Objective】The present paper aimed to study the effects of tobacco garlic crop rotation on bacterial community structure and its diversity.【Method】Based on the high throughput sequencing technology,the bacterial community structure and its diversity of tobacco garlic crop rotation with healthy tobacco rhizosphere soil were analyzed.【Result】The predominant bacteria were Proteobacteria,Actinobacteria,Chloroflexi,Firmicutes and Acidobacteria in the rhizoshere soil of test tobacco field in Dechang county,Liangshan prefecture,which the percentage of relative abundance was 83.31%-88.98%of total content.Before the tobacco transplant,the relative abundance of predominant bacteria was higher in susceptible tobacco fields with garlic crop than that in healthy tobacco field,and the bacterial diversity was higher,too.After the tobaccos were planted,the relative abundance of Firmicutes increased remarkably,which was in accord with the change of nutrient that there was a very significant positive correlation between them,and Firmicutes and Bacillus were higher in susceptible tobacco fields than that in healthy tobacco field,in which difference was significant.The bacterial diversity reduced and was lower than that of healthy tobacco field in the long-term,then it rose and exceeded in mature period of tobacco.It revealed that the garlic crop improved the adjusting ability of the bacterial community structure in tobacco field,and the morbidity of tobacco reduced to 6.5%from 50%in former years.【Conclusion】As a result,the tobacco garlic crop rotation could adjust the bacterial community structure of tobacco field to be healthier to reduce the morbidity of soil-borne disease observably.