套种对浙贝母根际土壤细菌群落结构和功能基因的影响

Effects of Intercropping on Bacterial Structure and Functional Genes in Rhizosphere Soil of Fritillaria Thunbergii

[目的]通过研究套种对浙贝母根际土壤细菌结构及功能基因的作用,探讨其改善浙贝母连作障碍的微生态机制。[方法]采用田间试验,将浙贝母与不同作物套种,利用Miseq测序及基于16S rRNA扩增子测序结果预测微生物群落(Phylogenetic Investigationof Communities by Reconstruction of Unobserved States,PICRUSt)功能分析解析浙贝母根际细菌群落结构及功能基因结构的组成差异。[结果]浙贝母与其他作物套种后,根际细菌的结构和多样性发生了明显改变。与单种浙贝相比,套种提高了根际细菌的多样性,其中浮霉菌门、酸杆菌门、放线菌门相对丰度显著上升。在属水平上,酸杆菌门的GP1属、GP2属、浮霉菌门的副球菌属以及放线菌门的放线菌属相对丰度明显升高,且生姜套种组中GP1属、GP2属以及副球菌属均为最高水平。细菌功能差异分析表明,套种提高了细胞壁/膜内源物质合成、次级代谢产物合成/转运/代谢、无机离子转运代谢以及防御机制4个方面功能基因丰度,而生姜套种组中这4个方面功能基因丰度最高。[结论]套种通过提高浙贝根际土壤细菌多样性,增加了生长促进细菌以及生防菌的含量,提高了浙贝产量以及药效成分含量。从微生态角度来说,浙贝母与生姜套种是最有利的方式。

[Objective] To investigate the effects of intercropping on the bacterial community structure and functional genes in the rhizosphere soil of F.thunbergii and explore its micro-ecological mechanism for improving the continuous cropping problem of F. thunbergii. [Methods] The rhizosphere bacterial community and functional gene structure of F. thunbergii were analyzed by Miseq sequencing analysis and PICRUSt function analysis.[Results]After interplanting with other crops, the structure and diversity of rhizosphere bacteria of F. thunbergii changed significantly. Compared with a single type of F. thunbergii, interplanting increased the diversity of rhizosphere bacteria. At the level of the phylum, the relative abundance of the Planctomycetes,Acidobacteria and Actinobacteria increased. At the level of genus, the relative abundance of GP1, GP2, Rhizomicrobiumand Gaiella increased, and GP1,GP2, Rhizomicrobium in the ginger intercropping group reached the highest level. Analysis of bacterial function differences showed that intercropping enhanced the abundance of functional gene in four aspects: The cell wall/membrane/envelope biogenesis, secondary metabolites biosynthesis/transport/catabolism, Inorganic ion transport/metabolism and defense mechanisms, and the four aspects of the ginger interplanting group had the highest functional gene abundance. [Conclusion] Interplanting increased the bacterial diversity in the rhizosphere of F. thunbergii, increased the content of growth-promoting bacteria and biocontrol bacteria which carried metabolic and defense-related functional genes,leading to the increased yield and the content of medicinal ingredients of F. thunbergii. From a micro-ecological point of view, intercropping with ginger should be the most advantageous way.