Abstract:

The diversity and composition of endophytic fundi from Sophora alopecuroides L. in arid and desolate areas of Ningxia were analyzed, which could also provide research methods and theory on rational development and use of endophytic fungi from Sophora alopecuroides L.. The endophytic fungi were separated and cultivated from 30 samples of the healthy roots, stems, leaves and seeds of Sophora alopecuroides L. by tissue-homogenate in six sample plots, where were sampled from different vegetations and soil types in the Baijitan National Nature Reserve of Ningxia. Endophytic fungi were classified according to their morphological characteristics of culture, bacterial colonies and spores and rDNA-ITS sequences analysis. Relative frequency (Rf), Shannon-wiener index (H), Margalef index (D) and Sorenson's similarity coefficient (CS) were calculated to analyze their characteristics of composition. The results showed that, 213 endophytic fungi were isolated from 30 samples, and they belong to 19 different genera, in which Fusarium, Alternaria and Phoma were dominant genera. The distribution of endophytic fungi from Sophora alopecuroides L. has some degree of tissue preference. Quantities of endophytic fungi from roots of Sophora alopecuroides L. were more than other tissues for the same plant. Index of diversity of endophytic fungi from stem of Sophora alopecuroides L. was the highest. However some similarity does exist for fungi found in Sophora alopecuroides L. under different living habitat. Shannon-wiener index (H) of endophytic fungi from Sophora alopecuroides L. were the most significantly in the sandy weeds(sample Ⅴ) and the least in desert steppes(sample Ⅲ). The community of endophytic fungi from Sophora alopecuroides L. of desert steppe(sampleⅠ) and sandy weeds(sample Ⅴ) have some similarity. Our results showed that the Sophora alopecuroides L. has abundant resources of endophytic fungi and the species diversity of endophytic fungi communities from Sophora alopecuroides L. is affected both by its host preference and by its different habitats.

Key words: Sophora alopecuroides L., Endophytic fungi, Diversity, rDNA-ITS sequence analysis

摘要：

为探索宁夏干旱荒漠区苦豆子（Sophora alopecuroides L.）内生真菌的多样性及区系组成，为苦豆子内生真菌的合理开发和利用提供理论依据。从宁夏白芨滩国家级自然保护区不同植被和土壤类型的6个样区采集苦豆子样品30份，采用组织匀浆法从植株的根、茎、叶和种子中分离内生真菌，根据培养性状、菌落、孢子等形态特征，结合rDNA-ITS序列分析对菌株进行鉴定；根据内生真菌的相对频率、物种多样性指数、丰富度指数和相似性系数分析其区系组成特点。结果表明，从30份样品中共分离得到内生真菌213株，分别属于19个属，其中镰刀菌属（Fusarium）、链格孢属（Alternaria）和茎点霉属（Phoma）为优势属。苦豆子内生真菌的分布具有一定的组织特异性，根部的内生真菌数量高于其他部位，茎部内生真菌多样性指数最高。植被类型中，沙生植被草原（样区Ⅴ）分离的内生真菌物种多样性指数最高，而荒漠草原（样区Ⅲ）最低。荒漠草原（样区Ⅰ）和沙生植被草原（样区Ⅴ）内生真菌群落有密切的相似性。可见，苦豆子蕴含丰富的内生真菌资源，其内生真菌具有很高的宿主特异性，且分布受生境影响。

关键词: 苦豆子, 内生真菌, 多样性, rDNA-ITS序列分析