【摘要】 目的：分离鉴定紫纹兜兰根内生真菌、果荚内生真菌及根际土壤真菌，揭示不同生态位真菌群落的多样性特征及系统发育关系。方法：采集紫纹兜兰的根、果荚及根际土壤样本，结合培养分离法和rDNA-ITS序列分析技术，对其进行鉴定及系统发育关系分析。结果：共获得46株真菌，涵盖3门15科27属，其中根内生真菌多样性最高（24株/22属），果荚（11株/7属）和根际土（11株/6属）真菌多样性低。系统发育分析显示，根与根际土壤中的Trichoderma属形成独立分支，而果荚特异性富集Colletotrichum属（4种形成密集分支）。营养型分化呈现显著分类单元特异性：担子菌门Tulasnella类群保持共生营养的祖先性状，子囊菌门中Colletotrichum（病理型）与Trichoderma（腐生/混合型）则表现出功能多样性。进化分析表明，共生策略在Tulasnella类群中高度保守，而病理营养型在子囊菌门中多次独立起源，表明宿主-病原协同进化可能驱动了功能辐射。结论：紫纹兜兰根内生真菌的多样性高于果荚和根际土壤真菌，且根与根际土壤中的Trichoderma属形成独立进化分支；担子菌门Tulasnella类群保持共生营养的祖先性状，宿主-病原体的协同进化可能驱动子囊菌门中病理型真菌功能多样化。本结果为解析兰科植物-真菌互作机制提供了关键的分类学和进化生物学依据。更多还原

【Abstract】 Objective: To isolate and identify root-endophytic, fruit capsule-endophytic, and rhizosphere soil fungi from Paphiopedilum purpuratum, and to reveal the diversity characteristics and phylogenetic relationships of fungal communities across these ecological niches. Methods: Root, fruit capsule, and rhizosphere soil samples of P. purpuratum were collected. Fungal isolation and identification were performed using traditional culture-dependent methods combined with rDNA-ITS sequence analysis to investigate their phylogenetic relationships. Results: A total of 46 fungal strains were isolated, belonging to 3 phyla, 15 families, and 27 genera. Root-endophytic fungi exhibited the highest diversity(24 strains/22 genera), while fungi in fruit capsules(11 strains/7 genera) and rhizosphere soils(11 strains/6 genera) showed relatively low diversity. Phylogenetic analysis revealed that Trichoderma species associated with roots and rhizosphere soils formed an independent clade, while Colletotrichum species were predominantly enriched in fruit capsules, with 4 species forming a dense clade within the same family. Additionally, the Tulasnella group(Basidiomycota) retained ancestral symbiotic traits, while Ascomycete species-Colletotrichum(pathogenic) and Trichoderma(saprotrophic/mixotrophic)-exhibited functional diversity. Nutritional type differentiation demonstrated significant taxon specificity, while pathogenic fungal lineages in Ascomycota exhibited functional divergence. Evolutionary analysis indicated that symbiotic strategies were highly conserved in the Tulasnella group, whereas pathogenic nutritional types originated independently multiple times in Ascomycota. This result suggested that host-pathogen co-evolution might have driven functional radiation. Conclusion: The diversity of root-endophytic fungi in P. purpuratum exceeded that of fruit capsules and rhizosphere soils. Trichoderma species associated with roots and rhizosphere soils formed an independent evolutionary clade. Furthermore, the Tulasnella group in Basidiomycota retained ancestral symbiotic traits, and host-pathogen coevolution might have promoted the functional diversification of pathogenic fungi in Ascomycota. These results provided key taxonomic and evolutionary biological evidence to elucidate the interaction mechanisms between orchids and fungi.更多还原