土壤细菌群落结构及功能多样性对烤烟连作的响应

Response of Soil Bacterial Community Structure and Functional Diversity to Flue-Cured Tobacco Continuous Cropping

探索烤烟连作对土壤细菌群落结构及功能多样性的影响,对深入理解连作障碍成因,制定土壤保育措施具有一定的理论和指导意义。利用高通量测序技术对云南省3个核心烟区不同连作年限(0、2、4和8年)耕层土壤细菌16S rDNA V3-V4片段进行测序,并结合土壤化学性质进行细菌群落分布与环境因子的相关性分析。结果表明,云南曲靖、红河烟区烟田土壤排前10位的细菌优势菌属相对丰度累积总和分别为11.43%~17.46%和15.82%~22.35%,细菌群落丰富度和多样性均随连作年限的延长极显著或显著增加,文山烟区烟田排前10位的土壤优势细菌菌属相对丰度累积总和为17.66%~23.08%,随连作年限的延长呈先降后升的趋势,细菌群落丰富度和多样性随连作年限的延长极显著提高;氨基酸代谢和其他次生代谢产物合成功能丰度是连作土壤细菌群落的主要代谢路径,随连作年限的增加区域间存在差异。冗余分析结果表明,土壤化学性质与细菌群落分布密切相关,其中pH是影响土壤细菌群落变化的核心环境因子,贡献值(18.12%)最高。综合而言,不同烟区土壤细菌群落多样性、功能多样性和优势菌属相对丰度随连作年限的增加,其变化趋势存在差异,调控土壤pH有利于维持相对稳定的土壤微环境。

Exploring the effects of flue-cured tobacco continuous cropping on soil bacterial community structure and functional diversity have theoretical and guiding significance for understanding the causes of continuous cropping obstacles and formulating soil conservation measure.The 16S rDNA V3-V4 fragments of soil bacteria were sequenced by high-throughput sequencing technology in three main tobacco fields of Yunnan province with different continuous cropping years(0,2,4 and 8 years),and the correlation between bacterial community distribution and environmental factors were analyzed.The results showed that the cumulative sum of the relative abundance of the top 10 dominant bacteria in Qujing and Honghe were 11.43%-17.46%,and 15.82%-22.35%,respectively.The richness and diversity of bacterial community were significantly increased with the increasing of continuous cropping years.The cumulative relative abundance of the top 10 soil dominant bacteria in Wenshan tobacco field ranged from 17.66%to 23.08%,and showed a trend of‘first decreasing and then increasing’with the extension of continuous cropping years.The richness and diversity of bacterial community was increased significantly with the extension of continuous cropping years.The abundances of amino acid metabolism and other secondary synthesis functions in soil bacteria community were the main metabolic pathway of continuous cropping soil bacteria,and increased with the increase of continuous cropping years,and there were differences between regions.The soil chemical properties were closely related to bacterial community distribution,and pH contributed the highest(18.12%)to soil bacterial community changes.In general,the diversity of soil bacterial community and functional diversity in different tobacco-producing area,and the relative abundance of dominant bacteria had different trends with the increase of continuous cropping years.Regulating soil pH was beneficial to maintaining a relatively stable of micro-environment of soil.