越南槐根系内生真菌组的结构及其宿主相似抑菌功能分析

【目的】分析比较越南槐野生与栽培根系内生真菌组的结构及宿主相似抑菌功能，为利用有益内生真菌组改善栽培宿主药材质量提供参考。【方法】采用组织块法分别从野生和栽培根系分离内生真菌，结合形态学和ITS序列特征鉴定内生真菌；分别采用琼脂块法和平板对峙法，以人体病原菌和丝状病原真菌为靶标菌，测定根系内生真菌组各分类单元的抑菌圈和抑制率。【结果】从越南槐野生和栽培根系分别分离鉴定得到234株36个分类单元和48株10个分类单元的内生真菌。野生根系内生真菌组的属、优势属、特有属、种、特有种的数目为栽培根系内生真菌组的3~5倍，其α多样性指数显著高于栽培根系内生真菌组（P<0.05），而两者间的β-多样性指数均极低。对于宿主相似抑菌活性分类单元的数目，野生根系内生真菌组是栽培根系内生真菌组的6~10倍，其中，分类单元Colletotrichum simmondsii对3种人体病原菌的抑菌圈直径均大于或等于阳性对照，Aspergillu.flavus、Phoma sp.、Purpureocillium lilacinum、Trichoderma asperellum、Trichoderma sp.、Talaromyces funiculosus、Fomitopsis sp.、Fusarium solani和Rhexocercosporidium sp.等9个分类单元对3种丝状病原真菌的抑制率均超过50%。【结论】越南槐野生根系内生真菌组具有生境特异性，生物多样性更丰富，且有强广谱的宿主相似抑菌功能，有益于在宿主根系合成结构独特、生物活性多样的代谢产物，进而赋予宿主药材独特的药效，可应用于改善栽培宿主药材质量。

Structure and similar-to-host antimicrobial function of endophytic fungal microbiome in Sophora tonkinensis Gagnep. Roots

【Objective】 To analyze and compare structure and similar-to-host antimicrobial function of endophytic fungal microbiome in wild and cultivated Sophora tonkinensis Gagnep., and to provide reference for quality improvement of host medicine cultivation using beneficial endophytic fungal microbiome.【Method】 Endophytic fungi were isolated from roots of wild and cultivated S. tonkinensis by tissue block method, and then were identified based on morphological and ITS sequence characteristics;through agar block method and plate confrontation, with human pathogens and filamentous pathogenic fungi as the target bacteria, inhibition zone and inhibition rate of taxa of endophytic fungal microbiome in S. tonkinensis roots were determined, respectively.【Result】 Endophytic fungi of 234 strains of 36 taxa, and 48 strains of 10 taxa, were respectively isolated and identified from wild and cultivated S. tonkinensis roots. The numbers of genera, dominant genera, endemic genera, species and endemic species of endophytic fungal microbiomes in wild S. tonkinensis roots were 3-5 times of those in cultivated type, with α diversity index of endophytic fungal microbiome in wild S. tonkinensis roots significantly higher than that in cultivated type(P<0.05) and β-diversity index was very low between the two. The number of similar-to-host antimicrobial activity taxa of endophytic fungal microbiome in wild S. tonkinensis roots was 6-10 times of that in cultivated S. tonkinensis roots. Diameters of the inhibition zone of taxon Colletotrichum simmondsii against 3 human pathogens were equal to or greater than those of positive control. Nine taxa, Aspergillu. flavus, Phoma sp., Purpureocillium lilacinum, Trichoderma asperellum, Trichoderma sp., Talaromyces funiculosus, Fomitopsis sp., Fusarium solani and Rhexocercosporidium sp., showed inhibition rates higher than 50% against 3 filamentous pathogenic fungi.【Conclusion】 Endophytic fungal microbiome in wild S. tonkinensis root has habitat specificity, higher biodiversity, and strong broad-spectrum similar-to-host antimicrobial function, which will be beneficial to synthesize metabolites with unique structure, diverse bioactivity, so as to develop special effects in host medicine, thus improving cultivated medicine quality.