从紫花苜蓿根释放到根际土壤中的化感物质是其入侵天然草地的重要因素。本研究的目的是探索化感物质之间的相互作用,土壤理化性质,土壤酶活性,和S.chamaejasme的根际土壤微生物群落沿生长覆盖梯度。采用高通量测序技术测定根际土壤样品的微生物组成,采用高效液相色谱法检测化感物质。根际土壤中生长覆盖率为0%的主要真菌门是担子菌,其他样地为子囊菌。变形杆菌和酸性杆菌是所有地点的优势细菌门。RDA分析表明,neochamaejasminB,chamaechromone,二氢瑞香素B与子囊菌和肾小球球菌呈正相关,与担子菌呈负相关。NeochamaejasminB和chamaechromone与变形杆菌和放线菌呈正相关,与酸杆菌和活生菌呈负相关。化感化学品,土壤理化性质,酶活性在一定程度上影响了根际土壤微生物群落的组成和多样性。当沙姆的生长覆盖率达到初级阶段时,对土壤理化性质和酶活性影响最大。
Allelochemicals released from the root of Stellera chamaejasme L. into rhizosphere soil are an important factor for its invasion of natural grasslands. The aim of this study is to explore the interactions among allelochemicals, soil physicochemical properties, soil enzyme activities, and the rhizosphere soil microbial communities of S. chamaejasme along a growth-coverage gradient. High-throughput sequencing was used to determine the microbial composition of the rhizosphere soil sample, and high-performance liquid chromatography was used to detect allelopathic substances. The main fungal phyla in the rhizosphere soil with a growth coverage of 0% was Basidiomycetes, and the other sample plots were Ascomycetes. Proteobacteria and Acidobacteria were the dominant bacterial phyla in all sites. RDA analysis showed that neochamaejasmin B, chamaechromone, and dihydrodaphnetin B were positively correlated with Ascomycota and Glomeromycota and negatively correlated with Basidiomycota. Neochamaejasmin B and chamaechromone were positively correlated with Proteobacteria and Actinobacteria and negatively correlated with Acidobacteria and Planctomycetes. Allelochemicals, soil physicochemical properties, and enzyme activity affected the composition and diversity of the rhizosphere soil microbial community to some extent. When the growth coverage of S. chamaejasme reached the primary stage, it had the greatest impact on soil physicochemical properties and enzyme activities.