拟疣柄牛肝菌属（Hemileccinum）分子系统发育与分类研究

	拟疣柄牛肝菌属（Hemileccinum）分子系统发育与分类研究
	李梅香
导师	杨祝良
关键词	拟疣柄牛肝菌属，形态分类，分子系统发育，物种多样性 Hemileccinum, Morphological classification, Molecular phylogeny, Species diversity
摘要	拟疣柄牛肝菌（Hemileccinum ?utara）隶属牛肝菌科绒盖牛肝菌亚科，能与壳斗科、松科等多科植物形成外生菌根互惠关系，具有重要的生态意义。该属成立较晚，属的范围模糊，已知物种间的系统亲缘关系也不明确，我国该属的物种多样性更不清楚。在大量取样基础上，本研究首先选取核糖体大亚基（nrLSU）、核糖体RNA的内转录间隔区（ITS）、编码RNA聚合酶II第一、二大亚基（rpb1、rpb2）和翻译延长因子1-α（tef1-α）基因等5个DNA片段进行扩增测序，获得该属相关序列共计200余条，基于多基因联合的分子系统发育分析，结合形态解剖学观察和生态分布特征等，对该属物种进行了精确界定，阐明了该属物种间的系统亲缘关系。研究结果如下：（1）该属全球至少有23个物种，我国至少分布有其中的15种，包括已报道的2种、本研究正式发表的4个新种和待发表的9个新种。我国曾报道有H. impolitum、H. subglabripes、H. hortonii和H. rubropunctum分布，但本研究表明这些原初描述于欧美的物种在我国可能并不存在，相关标本的特征（如子实体受伤变色、担孢子光滑等）表明它们是牛肝菌科其他属的物种。在此基础上，编制了该属全球物种的分类检索表。（2）分子系统发育分析显示拟疣柄牛肝菌属为一支持率较高的单系类群，但该属内的主干分支间的系统亲缘关系暂未得到很好解析。我国该属物种与分布于北美的物种更为近缘，如国产的H. ferrugineum、H. fulvum、H. brevisporum、H. brevipes与北美的H. floridanum聚为一支，国产的H. rugosum、H. duriusculum和北美的H. hortonii关系更为紧密，国产的H. parvum、H. ferrugineipes分别与北美的H. rubropunctum、H. subglabripes互为姐妹种。分布于欧洲的H. depilatum与H. impolitum（模式种）关系紧密，且系统位置较为独立。该属的基部类群分布于东亚和东南亚。（3）拟疣柄牛肝菌属的主要形态特征为子实体受伤不变色，菌盖表面常被污白色绒毛状鳞片，菌柄表面被淡色颗粒状鳞片，菌盖表皮主要为念珠型（epithelium）、近念珠型（subepithelium）至丝念珠型（hyphoepithelium），稀为平伏型（cutis），担孢子表面具近杆菌状或细疣状纹饰。; Fungi of the genus Hemileccinum ?utara, belonging to the subfamily Xerocomoideae in Boletaceae, are ecologically important because of their symbiotic associations with many plants in different families such as Fagaceae and Pinaceae. The genus has been recently erected, and its diagnostic morphological characters remain unclear. In addition, the phylogenetic relationships among its known species are not well elucidated and the species diversity of this genus in China are largely unrevealed. Based on large-scale sampling, five DNA loci, including ribosomal large subunit (nrLSU), internal transcribed spacer (ITS), encoding ribosomal RNA, genes encoding RNA polymerase II first (rpb1) and second (rpb2) large subunits and translation elongation factor 1-α (tef1-α), were determined for sequencing. A total of about 200 related sequences of this genus were obtained for multi-locus phylogenetic analysis. By integrating molecular phylogeny, morphological observations and ecological data, this study precisely identified the species of Hemileccinum and clarified their phylogenetic relationships. The main achievements of this studies are as follows: (1) There are at least 23 species of Hemileccinum in the world, and at least 15 of them occur in China. The Chinese species have been well studied, including 2 known species, 4 new species formally published by this study and 9 unpublished new species. This study significantly enriched the species diversity of Hemileccinum in China. It is preliminarily confirmed that the Chinese specimens once identified as the European and North American species were in fact misidentified, and probably represent the species of other genera in Boletaceae due to the distinctive color change of basidiomata when injured and the smooth basidiospores under SEM. Meanwhile, a dichotomous key to the species of this genus worldwide was provided. (2) Molecular phylogenetic analysis indiacted that Hemileccinum was a monophyletic group with high statistic support, but the phylogenetic relationships among the main clades in the genus were not well resolved. Phylogenetically, the Chinese species of Hemileccinum were more closely related to the those from North America than from Europe. For example, H. ferrugineum, H. fulvum, H. brevisporum, H. brevipes from China were clustered with H. floridanum from North America. The Chinese H. rugosum and H. duriusculum were more closely related to H. hortonii from North America, and the Chinese H. parvum and H. ferrugineipes are sister to H. rubropunctum and H. subglabripes from North America; respectively. The two species from Europe, namely H. depilatum and H. impolitum (type species of the genus) were the closest related species and formed an independent lineage. The basal taxa of the genus were from East Asia and Southeast Asia. (3) The morphological diagnostic characters of Hemilccinum are as follows: the basidioma is unchanging when injured.
语种	中文
	2022-05
学位授予单位	中国科学院大学
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/75115
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	李梅香. 拟疣柄牛肝菌属（Hemileccinum）分子系统发育与分类研究[D]. 中国科学院大学,2022.

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