目的 以根腐病不同发病程度的沙氏鹿茸草Monochasma savatieri及其根际土壤为研究对象，系统测定沙氏鹿茸草品质指标与土壤理化性质，结合宏基因组学技术，探讨“植物-土壤-微生物”间的互作机制。方法 通过以根腐病3个发病进程的沙氏鹿茸草及其根际土作为研究对象，测定沙氏鹿茸草根际土土壤理化性质、沙氏鹿茸草主要活性成分含量；沙氏鹿茸草根际土进行宏基因组测序。结果 根际土pH、电导率（EC）和有效磷随着病害程度加深而显著升高，全碳和全氮含量呈现相反趋势。随着根腐病发展，沙氏鹿茸草总黄酮、木犀草素、芹菜素和异毛蕊花糖苷含量显著降低而毛蕊花糖苷含量提高。微生物多样性随着病害程度加深而上升，病害后期土壤中与土传病害相关的病原菌如镰刀菌属、芽枝霉属和葡萄孢属丰度增加，有益菌木霉属亦丰度上升。京都基因与基因组百科全书（Kyoto encyclopedia of genes and genomes，KEGG）注释下的代谢相关通路，如脂肪酸代谢、乙醛酸和二羧酸代谢、β-丙氨酸代谢和丙酮酸代谢等，发病后期组较健康组和发病中期组更加富集。pH值、EC值与潜在病原菌丰度呈显著正相关。与沙氏鹿茸草总黄酮、木犀草素、芹菜素和毛蕊花糖苷呈现显著正相关的微小杆菌属、Drechslerella属、绿僵菌属和木霉属等可能参与土壤微生态改善及植物抗病过程。结论 通过对根腐病不同进程条件下“沙氏鹿茸草-微生物-土壤”系统中关键指标的综合关联分析，较全面系统地阐述了根腐病进程中三者的变化规律与互作关系，可为揭示沙氏鹿茸草根腐病发生的微生态机制，以及通过土壤和根际微生物调控防治沙氏鹿茸草根腐病提供依据。

Objective Root rot has become a bottleneck restricting the industrial development of Monochasma savatieri, however, current understanding regarding its pathogenesis remains poorly understood. Methods This study took three groups of M. savatieri with different root rot progress and their rhizosphere soil as the research objects, and determined the soil physical and chemical properties of rhizosphere soil and the content of main active components of M. savatieri; metagenomic sequencing of the rhizosphere soil of M. savatieri. Results With the development of root rot, the physical and chemical properties of rhizosphere soil changed significantly. Among them, pH, electrical conductivity (EC) and available phosphorus increased significantly with the deepening of disease severity, while the contents of total carbon and total nitrogen showed the opposite trend. And the contents of total flavonoids, luteolin, apigenin and isoverbascoside were significantly reduced, while the content of verbascoside was increased. The microbial diversity increased with the deepening of disease severity, and the abundance of pathogenic bacteria related to soil-borne diseases in the soil, such as Fusarium, Cladosporium and Botrytis, as well as beneficial Trichoderma, increased in the later stage of the disease. The metabolic related pathways under KEGG annotation, such as fatty acid metabolism, glyoxylic acid and dicarboxylic acid metabolism, β-alanine metabolism and pyruvate metabolism, were more enriched than those in the healthy group and the mid-stage disease group. The pH value and EC value were significantly positively correlated with the abundance of potential pathogenic fungi. The genera such as Microbacterium, Drechslerella, Metarhizium and Trichoderma, which show significant positive correlations with total flavonoids of M. savatieri, luteolin, apigenin and verbascoside, may be involved in the improvement of soil microecology and the process of plant disease resistance. Conclusion Through a comprehensive correlation analysis of key indicators in the “M. savatieri -Microorganisms-Soil” system under different progression stages of root rot, this study systematically elucidates the patterns of change and interaction relationships among the three during the disease progression. The findings provide a basis for uncovering the microecological mechanisms underlying the occurrence of root rot in M. savatieri, as well as for developing control strategies through the regulation of soil and rhizosphere microorganisms.

R282.6

国家自然科学基金项目（81773834）