箭叶淫羊藿不同时期根际微生物群落组成及其与有效成分累积的相关性分

Community and diversity of rhizosphere microorganisms and its correlation with active ingredients of Epimedium sagittatum in different growth stages

目的 通过分析箭叶淫羊藿Epimediumsagittatum不同生育期根际微生物群落结构及其与主要药用有效成分累积之间的相关性,探讨箭叶淫羊藿根际土壤微生物对其药材有效成分的影响,为箭叶淫羊藿的优质高产栽培提供科学依据。方法 以三年生箭叶淫羊藿的根际土为研究对象,采用高通量测序技术对根际细菌和真菌群落结构进行分析,同时测定根际土壤理化性质、酶活性及不同生育期药材总黄酮、淫羊藿苷等有效成分含量,通过皮尔逊相关性分析探究土壤生态因子与有效成分之间的关系。结果 高通量测序结果显示,箭叶淫羊藿根际细菌优势菌属包括Candidatus_Solibacter、苔藓杆菌属、嗜酸栖热菌属、芽单胞菌属等,其中,Candidatus_Solibacter属在5个生长时期的平均丰度值最高。根际真菌优势菌属中被孢霉属相对丰度占比最大,在花蕾期样品中的丰度值高达44.27%。UPGMA聚类和非度量多维标定法(NMDS)分析表明,花蕾期、盛花期、果实膨大期及盛果期的根际土壤细菌和真菌结构相似,而药材质量稳定期与前4个时期的根际微生物群落结构存在明显差异。同时,皮尔逊相关性分析结果显示:总黄酮含量与有效磷呈显著正相关,与Candidatus_Solibacter属、藓杆菌属呈极显著正相关;淫羊藿苷与有机质、苔藓杆菌属呈显著正相关,与碱解氮、有效磷、Candidatus_Solibacter属呈极显著正相关,而与过氧化氢酶、硝化螺菌属呈显著负相关;朝藿定A和朝藿定B与碱解氮、蔗糖酶显著正相关,与有效磷、Candidatus_Solibacter属、嗜酸栖热菌属、慢生根瘤菌属及显著正相关,而与脲酶、酸杆菌属显著负相关,与p H、过氧化氢酶、硝化螺菌属呈极显著负相关。朝藿定C与有机质、碱解氮、苔藓杆菌属呈正相关,与有效磷、Candidatus_Solibacter属相对丰度呈极显著正相关,与硝化螺菌属呈显著负相关。结论 通过分析箭叶淫羊藿不同生育期根际微生物群落结构及其多样性,掌握了其根际微生物资源状况,研究发现根际微生物与土壤理化性质及酶活性一起参与有效成分的合成与积累,为箭叶淫羊藿栽培过程中土壤根际微生物的群落分布提供了研究资料,并为箭叶淫羊藿根际微生物资源的挖掘及其优质高产栽培提供参考依据。

Objective To explore the effect of rhizosphere microbial on the quality of Epimedium sagittatum in different growth stages by analyzing the correlation between community and diversity of rhizosphere microbial and the content of active ingredients,so as to provide the reference for its high-quality and high-yield cultivation. Methods Taking the rhizosphere soil of three-year-old E. sagittatum in different growth stages as the object, high-throughput sequencing technology was used to analyze the community structure and diversity of rhizosphere bacteria and fungi. At the same time, the physicochemical properties and enzyme activities of rhizosphere soil and the contents of active ingredients such as total flavonoids and icariin were determined. Pearson correlation analysis was used to explore the relationship between soil ecological factors and effective ingredients. Results High-throughput sequencing results showed that Candidatus_Solibacter, Bryobacter, Acidothermus and Gemmatimonas were the dominant bacterial genus in the rhizosphere of E. sagittatum. Candidatus_Solibacter had the highest average abundance in the five growth periods.Among the dominant rhizosphere fungi, Mortierella accounted for the largest proportion of relative abundance, which was as high as 44.27% in the flowering stage samples. UPGMA cluster analysis and NMDS analysis showed that the structures of rhizosphere soil bacteria and fungi were similar in flowering, full-bloom, fruit expansion and full productive stage, while there were significant differences in rhizosphere microoranganism community structure between the stable quality stage and the first four stages. Pearson correlation analysis showed that the content of total flavonoids was significantly positively correlated with available phosphorus, and was extremely significantly positively correlated with Candidatus_Solibacter and Bryobacter. Icariin was significantly positively correlated with organic matter and Bryobacter, extremely significantly positively correlated with alkali hydrolyzable nitrogen,available phosphorus, Candidatus_Solibacter, and significantly negatively correlated with catalase and Nitrospira;Epimedin A and B were positively correlated with alkali-hydrolyzed nitrogen and sucrase, and significantly positively correlated with available phosphorus, Candidatus_Solibacter, Acidothermus, and chronic rhizobia, while significantly negatively correlated with urease and Acidobacteria, and extremely significantly negatively correlated with pH, catalase and Nitrospira. Epimedin C was positively correlated with organic matter, alkali-hydrolyzed nitrogen and Bryobacter, significantly positively correlated with available phosphorus and relative abundance of Candidatus_Solibacter, and negatively correlated with Nitrospira. Conclusion Through the analysis of the rhizosphere microbial community structure and diversity of E. sagittatum at different growth periods, the status of its rhizosphere microbial resources was mastered. The study found that rhizosphere microbes, together with soil physical and chemical properties and enzyme activities, participate in the synthesis and accumulation of effective ingredients. This study provides research data for the community distribution of soil rhizosphere microorganisms during the cultivation of E. sagittatum, and provides a reference for the excavation of rhizosphere microbial resources and its high-quality and high-yield cultivation.