[关键词]
[摘要]
目的 探讨蒙古黄芪Astragalus membranaceus var. mongholicus内生真菌的菌群结构、多样性及其对病原菌的拮抗活性，为黄芪内生真菌资源开发利用提供依据。方法 采集9个产地的新鲜蒙古黄芪样本，对蒙古黄芪3个部位（根、茎、叶）的内生真菌进行分离与纯化，根据菌株的培养特征与ITS分子序列扩增对菌种进行鉴定；分析内生真菌菌群结构，并采用Shannon-Wiener多样性指数（H’）和Simpson多样性指数（I）分析多样性；采用平板对峙法考察内生真菌对8种常见病原菌的拮抗活性。结果 共分离得到蒙古黄芪内生真菌1 531株，ITS分子鉴定为22个分类单位，归属于真菌界1门3纲4目7科10属；根、茎、叶共有内生真菌11种；9个产地优势共有目为肉座菌目（Hypocreales）与多孔菌目（Pleosporales）；组织部位方面，内生真菌H’指数与I指数分别在1.942～2.265与0.805～0.855，以根的多样性最高；产地方面，内生真菌内生真菌H’指数与I指数分别在1.202～2.193与0.514～0.850，以内蒙古自治区和林格尔县的多样性最高；68.18%的内生真菌对8种常见病原菌均有抑制作用，其中AMH104粉红螺旋聚孢霉菌Clonostachys rosea、AMH95蜡蚧刺束梗孢菌Akanthomyces lecanii抑菌效果较好。结论 蒙古黄芪内生真菌资源丰富，筛选得到的活性菌株为蒙古黄芪病害防治提供了候选菌株。
[Key word]
[Abstract]
Objective To investigate the fungal community and diversity of endophytic fungi in Astragalus membranaceus var. mongholicus and their antagonistic activity against pathogens and provide a basis for the utilization of endophytic fungal resources in A. membranaceus var. mongholicus. Methods Fresh A. membranaceus var. mongholicus samples were collected from nine different regions in China. Endophytic fungi were isolated and purified from three tissues (root, stem, and leaf) and further identified using culture characteristics of the strain and ITS molecular sequence amplification. After identification, fungal community were analyzed, and its diversity was assessed using the Shannon-Wiener diversity index (H’) and Simpson diversity index (I). The antagonistic activity of endophytic fungi against eight common pathogens was evaluated using the plate confrontation method. Results A total of 1 531 strains of endophytic fungi were gained and identified into 22 taxonomic units by ITS, belonging to one phylum, three classes, four orders, seven families, and ten genera. Eleven endophytic fungal species were shared among the roots, stems, and leaves. The most dominant common orders in the nine producing areas were Hypocreales and Pleosporales. The H’ and I indices of the tested endophytic fungi in tissues ranged from 1.942 to 2.265 and 0.805 to 0.855, respectively, with the highest diversity index in roots. The H’ and I indices of endophytic fungi from nine regions ranged from 1.202 to 2.193 and 0.514 to 0.850, respectively, with the highest diversity found in Helingeer County, Inner Mongolia Autonomous Region. Endophytic fungi (68.18%) exhibited inhibitory effects against eight pathogens. Among them, AMH104 (Clonostachys rosea) and AMH95 (Akanthomyces lecanii) demonstrated the strongest antagonistic effects. Conclusion A. membranaceus var. mongholicus harbors abundant endophytic fungal resources, and the anti-pathogenic active strains screened provide potential candidates for disease prevention and control of A. membranaceus var. mongholicus.
[中图分类号]
R286.2
[基金项目]
浙江省重点研发计划项目（2021C04029）；浙江中医药大学松阳研究院科技攻关专项（SY-Z-2024501）
