近日,国际著名杂志在Fungal Genetics and Biology在线刊登了中科院昆明植物研究所研究人员的最新研究成果“Multigene molecular phylogenetics reveals true morels (Morchella) are especially species-rich in China,”,文章中,研究者揭示了其在羊肚菌物种多样性与起源演化研究取得的新进展。
羊肚菌是珍稀名贵的食用和药用真菌,在国内外市场备受青睐,干品价格高达2000元/kg。由于该属物种形态特征高度可塑,仅靠传统的形态学特征基本无法辨别物种。过去我国报道的新分类单元仅5个,且种间区别不易界定。该属个别种有望实现商业化栽培,但尚无可靠的物种识别标准或物种DNA条形码,也无准确的科学名称,这既不利于知识产权申请,也不利于今后的良种选育。开展羊肚菌物种多样性、系统发育与起源演化研究,可为羊肚菌人工栽培、物种资源利用与保护提供科学依据。
中国科学院昆明植物研究所杨祝良研究组,在2003-2011年间对我国21省市羊肚菌资源进行了广泛野外调查和采集,积累标本900余份,在形态学研究基础上,对其中的361份进行了ITS测序,据此筛选出可能为不同物种的代表标本70份。利用另外4个分子标记对它们进行了测序,结合业已发表的有关序列,与美国农业部O’Donnell实验室合作,采用新近流行的分析方法,对羊肚菌属的物种多样性、起源时间、分布格局、扩散路线和演化历史进行了研究。部分研究成果已在真菌学主流期刊Fungal Genetics and Biology在线发表。
该文的主要新意在于:发现中国共有30个羊肚菌物种,其中20种迄今仅见于中国,11种为新物种,中国的物种比整个欧洲的或北美的都多,提出东亚或中国是羊肚菌属的现代物种多样性中心;羊肚菌属可能在晚侏罗纪至早白垩纪时起源于北美西部,多数物种可能通过白令陆桥传播至亚洲,并且欧亚物种之间进行过交流和扩散;晚中新世时,干旱和气候的变化导致了北美和欧洲两地区部分物种灭绝,生境的片断化引起部分异域物种形成;青藏高原隆升与物种分化有密切联系,东亚约90%的物种是自中中新世至今分化出来的(见附图)。
该研究得到NSFC-云南联合基金重点项目(U0836604)、国家重点基础研究发展计划(2009CB522300)等的资助。(生物谷Bioon.com)
doi:10.1016/j.fgb.2012.03.006
PMC:
PMID:
Multigene molecular phylogenetics reveals true morels (Morchella) are especially species-rich in China
Xi-Hui Dua, c, Qi Zhaoa, Kerry O’Donnellb, Alejandro P. Rooneyb, Zhu L. Yanga, ,
The phylogenetic diversity of true morels (Morchella) in China was estimated by initially analyzing nuclear ribosomal internal transcribed spacer (ITS) rDNA sequences from 361 specimens collected in 21 provinces during the 2003–2011 growing seasons, together with six collections obtained on loan from three Chinese herbaria. Based on the results of this preliminary screen, 40 Esculenta Clade (yellow morels) and 30 Elata Clade (black morels) were chosen to represent the full range of phylogenetic diversity sampled. To investigate their species limits, we generated DNA sequences from portions of three protein-coding genes (RPB1, RPB2 and EF-1α) and domains D1 and D2 of the nuclear large subunit (LSU) rDNA for all 70 collections. To fully assess evolutionary relationships, previously published multilocus DNA sequence data representing all known Morchella species was included in this study. Phylogenetic analyses employing maximum parsimony and maximum likelihood frameworks resolved 30 species in China compared with 22 in Europe and 19 within North America. Eleven novel phylogenetically distinct species were discovered in China, including two species within the Elata Clade and nine within the Esculenta Clade. Of the 30 species in China, 20 appear to be endemic, nine were also represented in Europe, and four putatively fire-adapted species have disjunct distributions in China, Europe and western North America. Although the diversification time estimates place the Esculenta Clade in China as early as the late Cretaceous and the Elata Clade by the early Oligocene, 27 of the 30 species evolved between the middle Miocene 12 Mya and present.