东祁连山高寒灌丛草甸小叶金露梅根部内生真菌多样性对季节的响应

Seasonal response of endophytic fungal diversity in roots of Potentilla parvifolia in alpine scrub meadow of eastern Qilian Mountains

摘要:

【目的】明确高寒地区灌木小叶金露梅（Potentilla parvifolia）根部可培养内生真菌的多样性和季节变化。【方法】以东祁连山的优势灌木小叶金露梅为试验材料，利用组织培养法分离根部的内生真菌，用形态鉴定和 ITS 分子测序相结合进行真菌鉴定并分析其季节多样性。【结果】春季、夏季和秋季在小叶金露梅根段组织中分离得到 71 株真菌纯培养物，归属于 5 纲 5 目 5 科 6 属 8 个分类单元；不同季节的小叶金露梅根部内生真菌种类和数量存在一定差异，从多样性指数来看，Shannon-Wiener 指数和 Simpson’s diversity 指数表现为春季（1. 57，0. 75）＞夏季（1. 26，0. 69）＞秋季（1. 08，0. 62）。春季根部内生真菌多样性高于夏季和秋季，但优势属均为脉孢菌属（Neurospora）和曲霉属（Aspergillu）；春季特有属为青霉属（Penicillium）和色串孢属（Torula）；赭霉属（Ochroconis）为夏季特有属，葡萄孢属 （Botrytis）为秋季特有属。【结论】不同季节小叶金露梅根部均分离得到了内生真菌，且内生真菌在小叶金露梅根部的定殖存在季节差异性，春季根部内生真菌多样性较高。

Abstract:

【Objective】 To determine the diversity and seasonal variation of culturable endophytic fungi in the roots of Potentilla parvifolia in alpine region.【Method】Potentilla parvifolia，a dominant shrub in the eastern Qilian Mountains was used as the test material. The endophytic fungi in root were isolated by tissue culture，and their seasonal diversity was analyzed by morphological identification combined with ITS molecular sequencing.【Result】71 pure fungi were isolated from the tissue of the golden dew rhizome in spring，summer and autumn，belonging to 8 taxa of 5 classes，5 orders，5 families，6 genera. There were some differences in the species and quantity of endophytic fungi in the roots of Potentilla parvifolia in different seasons. From the diversity index，Shannon ‐Wiener index and Simpson's diversity index showed as spring （1. 57，0. 75） ＞ summer （1. 26，0. 69） ＞ autumn （1. 08，0. 62）. The diversity of endophytic fungi in the roots in spring was higher than that in summer and autumn，but the dominant genera were Neurospora and Aspergillus. The endemic genera in spring were Penicillium and Torula； Ochroconis was endemic in summer，and Botrytis was endemic in autumn.【Conclusion】 The endophytic fungi were isolated from the roots of Potentilla parvifolia in different seasons，and the endophytic fungi colonization in the roots of Potentilla parvifolia had seasonal differences，The diversity of endophytic fungi in the roots in spring was higher.