Abstract: In order to determine the effect of different continuous cropping years on microbial community structure in tobacco-planting soil, the paper selected typical tobacco-planting regions, collected soil samples with different continuous cropping years, and analyzed differences between bacteria and fungi community structure in tobacco-planting soil with different continuous cropping years by high-throughput sequencing technology. Results showed that the OTUs numbers of bacterial species in tobacco-planting soil for one year continuous cropping was the most, and that of fungal species for 4 years continuous cropping was the maximum. The bacteria ratio of Proteobacteria were the highest in soil with years continuous cropping. The proportion of Actinobacteria and Crenarchaeota in continuouse cropping soil showed a certain increasing trend, and at the same time, differences between soil bacteria community became large. The ratio of soil fungi were mainly Ascomycota. The proportion of Zygomycota in tobacco-planting soil fungi showed an increasing trend with the process of continuous cropping years. The fungal community composition in tobacco-planting soil for 2 and 4 years continuous cropping had certain similarity. In conclusion, continuous tobacco cropping decreased the diversity of soil bacteria and increased the diversity of fungi. Great changes had taken place in the structure of bacteria and fungi communities in tobacco-planting soil for 4 years continuous cropping.

Key words: continuous cropping, tobacco-planting soil, microbial community structure, fungi, bacteria

摘要： 为明确不同连作年限对植烟土壤微生物群落结构的影响，选择具有代表性的植烟区域，分别采集不同连作年限的土壤样品，利用高通量测序技术分析不同连作年限植烟土壤细菌和真菌群落结构的差异。结果表明，连作1年土壤样品细菌OTUs数目最多，连作4年土壤样品真菌OTUs数目最多。不同连作年限植烟土壤细菌均以变形菌门（Proteobacteria）比例最高，随着连作年限的增加土壤放线菌门（Actinobacteria）和泉古菌门（Crenarchaeota）丰富度呈现一定的增加趋势，同时土壤细菌的群落差异变大；不同连作年限植烟土壤真菌均以子囊菌门（Ascomycota）比例最高，随着连作年限的增加,植烟土壤真菌中的接合菌门 （Zygomycota）呈现上升趋势，连作2年和4年的植烟土壤真菌菌群组成具有一定的相似性。综合分析，连续种植烤烟降低了土壤细菌多样性，提高了土壤真菌多样性，连作4年植烟土壤的细菌和真菌群落结构组成均发生较大变化。

关键词: 连作, 植烟土壤, 微生物群落结构, 真菌, 细菌