不同种植年限银柴胡根际土壤微生物群落结构变化

Changes of rhizosphere soil microbial community structure of Stellaria dichotoma L.var.lanceolata Bge.planted for different years

【背景】银柴胡(Stellaria dichotoma L.var.lanceolata Bge.)为石竹科繁缕属多年生草本植物,以干燥根入药。【目的】探究道地产区不同种植年限银柴胡根际土壤微生物群落结构变化,以及微生物群落与土壤理化因子、药材有效成分的相关性。【方法】利用Illumina高通量测序技术对1、2、3、7年生银柴胡根际土壤细菌16S rRNA基因和真菌ITS序列进行测序分析,采用常规分析方法测定土壤性质、药材总黄酮和总甾醇含量。【结果】随着银柴胡种植年限延长,细菌丰富度变化较小,多样性升高,而真菌的丰富度和多样性均升高。细菌中主要优势菌群均为放线菌门(Actinobacteriota)、变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi),在根际土壤真菌中子囊菌门(Ascomycota)和担子菌门(Basidiomycota)为优势菌群;不同种植年限银柴胡优势菌属差别较大。3年生银柴胡中总甾醇和总黄酮含量显著高于其他年限。相关性分析表明,pH、碱解氮(alkali-hydrolyzable nitrogen,AN)与银柴胡根际土壤微生物群落具有很大相关性。拟无枝酸菌属(Amycolatopsis)、被孢霉属(Mortierella)、光黑壳属(Preussia)、青霉属(Penicillium)等类群与银柴胡主要活性成分呈显著正相关。【结论】该研究初步揭示了与银柴胡有效成分有关的标志根际土壤微生物,为实现银柴胡的优质生产提供了理论依据。

[Background]Stellaria dichotoma L.var.lanceolata Bge.is a perennial herb of Caryophyllaceae,with dried roots(Stellariae Radix)as the medicinal part.[Objective]To explore the changes of rhizosphere soil microbial community structure of S.dichotoma var.lanceolata planted for different years in genuine production area and the correlations of microbial community with soil physical and chemical factors and active components in Stellariae Radix.[Methods]Illumina high-throughput sequencing of bacterial 16S rRNA gene and fungal ITS sequences were performed to reveal the microbial community structures in the rhizosphere soil samples of S.dichotoma var.lanceolata planted for 1,2,3,and 7 years.The soil properties and the content of total flavonoids and total sterols in Stellariae Radix were determined by conventional methods.[Results]As the planting years of S.dichotoma var.lanceolate increased,the bacteria showed little change in the richness and increased diversity,while the fungi presented increased richness and diversity.The dominant bacteria were Actinobacteriota,Proteobacteria,and Chloroflexi,and the dominant fungi were Ascomycota and Basidiomycota in the rhizosphere soil.The dominant microbial genera varied significantly in the rhizosphere soil samples of S.dichotoma var.lanceolata planted for different years.In addition,the content of total sterols and total flavonoids in 3-year-old Stellariae Radix were significantly higher than those in the samples of other planting years.The correlation analysis showed that pH and alkali-hydrolyzable nitrogen had strong correlations with the microbial community in the rhizosphere soil.Amycolatopsis,Mortierella,Preussia,and Penicillium had significantly positive correlations with the main active components in Stellariae Radix.[Conclusion]The study preliminarily revealed the rhizosphere soil microorganisms related to the active components in Stellariae Radix,which provided a theoretical basis for the high-quality production of this herbal medicine.