林下种植重楼和珠子参后土壤细菌结构与功能变化

Changes in Structure and Function of Soil Bacteria After Paris polyphylla andPanax japonicus Cultivated Understory

为探索不同植被下土壤细菌群落构成和功能差异及其与土壤因子的关系,采用高通量测序,对移栽重楼和珠子参根际及原始林地土壤细菌进行16SrRNA测序。结果表明,重楼根际土壤的Chao1和ACE指数显著高于原始林地土壤。Simpson和Shannon指数与土壤因子的相关性不显著,Chao1和ACE指数与EC、WC、TP、MBC、MBP、AP呈显著正相关,与AK、MBC:MBP、NiR、SUC呈显著负相关。变形菌门和酸杆菌门在原始林地土壤中丰度最高,拟杆菌门在重楼根际土壤中丰度最高,厚壁菌门在珠子参根际土壤中丰度最高。KEGG分析发现,原始林地土壤在细胞过程、环境信息处理、遗传信息处理与代谢等4个一级功能层面均有丰度较高的基因,重楼根际土壤中丰度较高的基因主要位于代谢层面,而珠子参根际土壤则是遗传信息处理层面的个别基因丰度较高,和KEGG功能基因丰度具有较高相关性的土壤因子与调控Chao1和ACE指数的土壤因子较为类似,说明细菌群落组成与基因功能紧密相关。此外,重楼和珠子参根际土壤均表现出次生盐渍化和温室气体排放增强的现象。

To explore the differences in soil bacterial community composition and function among different vegetation types as well as the relationships between bacterial community composition and soil characteristics,the high-throughput sequencing platform was used to conducting 16S rRNA sequencing on soil bacteria in the rhizosphere of Paris polyphylla,Panax japonicus and in the original woodland.It was found that the Chao1 and ACE indexes of the rhizosphere soil of P.polyphylla were significantly higher than those of the original forest soil.Simpson and Shannon indexes were not significantly correlated with soil characteristics,but Chao1 and ACE indexes were significantly and positively correlated with electrical conductivity,water content,total phosphorus,microbial biomass carbon,microbial biomass phosphorus and available phosphorus,and negatively correlated with available potassium,ratio of microbial biomass carbon to microbial biomass phosphorus,nitrite reductase and sucrase.The highest abundance of Proteobacteria and Acidobacteria was in the original woodland soil,the highest abundance of Bacteroidetes was in the rhizosphere soil of P.polyphylla,and the highest abundance of Firmicutes was in the rhizosphere soil of P.japonicus.KEGG(Kyoto encyclopedia of genes and genomes)analysis showed that there was relatively high abundance of genes in four primary functional levels in original forest soil including cellular processes,environmental information processing,genetic information processing and metabolism,the genes with higher relative abundance in rhizosphere soils of P.polyphylla were mainly located at the metabolism level,the relative abundance of genes in the genetic information processing was relatively high in rhizosphere soils of P.japonicus.The soil characteristics that had correlation with KEGG functional gene abundance were similar to the soil characteristics that regulated Chao1 and ACE indexes,indicating that bacterial community composition was closely related to gene function.In addition,secondary salinization and greenhouse gas enhancement were observed in the rhizosphere soil of the two species.