陕西不同生境核桃内生真菌多样性

Diversity of fungat endophytes from Juglans regia under different habitats in Shaanxi

摘要:

【目的】了解核桃内生真菌组成、分布等多样性特性，为活性菌株筛选、作用机理研究等奠定基础。【方法】采用组织分离法对不同季节、不同生境、不同部位的核桃内生真菌进行分离，以形态学和分子生物学相结合的方法进行鉴定，通过定殖率、分离率、分离频率、Shannon-Wiener多样性指数等分析核桃内生真菌的多样性。【结果】共分离获得核桃内生真菌1 450株，隶属于47个属，其中链格孢属Alternaria为优势类群，占菌株总数的20.00%，镰孢属Fusarium和酵母属Saccharomyces相对较多，分别占菌株总数的8.34%和8.14%。核桃不同部位内生真菌的多样性指数(H′)和均匀度指数都以两年生茎的最高，分别为1.15和0.36；不同生境核桃中，山阳的多样性指数(H′)和均匀度最高，分别为1.42和0.42；秋冬两季中，秋季的指标较高，分别为1.92和0.54。【结论】不同部位、不同生境、不同季节核桃都具有丰富的内生真菌且多样性存在差异；相似性系数、均匀度指数反映出，核桃内生真菌在一定程度上相对稳定。

Abstract:

[Objective] Diversity of fungal endophytes associated with Juglans regia was studied. [Methods] Fungal endophytes from different seasons, habitats and parts of Juglans regia were isolated by tissue expand method. Strains were classified by morphology and similarity of internal transcribed spacer (ITS) sequence by ClustalX 2.0. Composition, diversity and preference of fungal endophytes were analyzed by the colonization frequency (CF), isolation rate (IR), isolation frequency (IF), Shannon-Wiener biodiversity index (H′). [Results] In total 1 450 fungal endophytes were isolated from Juglans regia and classified into 47 genera. Among them, Alternaria (20.00%), Fusarium (8.34%), Saccharomyces (8.14%) were the dominant genera. The diversity of fungal endophytes and Evenness index (E) were maximum in 2-yesr-old twig, Shanyang, spring with Shannon-Wiener index 1.15, 1.42, 1.92 and evenness 0.36, 0.42, 0.54, respectively. [Conclusion] There was some difference in diversity of fungal endophytes isolated from different parts, habitats, season of Juglans regia. Meanwhile, the similarity coefficient and evenness show that the fungal endophytes isolated from Juglans regia were relatively stable.