近日,國際著名雜志在Fungal Genetics and Biology在線刊登了中科院昆明植物研究所研究人員的最新研究成果“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種多樣性與起源演化研究取得的新進展。
羊肚菌是珍稀名貴的食用和藥用真菌,,在國內(nèi)外市場備受青睞,,干品價格高達2000元/kg。由于該屬物種形態(tài)特征高度可塑,,僅靠傳統(tǒng)的形態(tài)學(xué)特征基本無法辨別物種,。過去我國報道的新分類單元僅5個,且種間區(qū)別不易界定,。該屬個別種有望實現(xiàn)商業(yè)化栽培,,但尚無可靠的物種識別標(biāo)準(zhǔn)或物種DNA條形碼,也無準(zhǔn)確的科學(xué)名稱,,這既不利于知識產(chǎn)權(quán)申請,,也不利于今后的良種選育。開展羊肚菌物種多樣性,、系統(tǒng)發(fā)育與起源演化研究,,可為羊肚菌人工栽培、物種資源利用與保護提供科學(xué)依據(jù),。
中國科學(xué)院昆明植物研究所楊祝良研究組,,在2003-2011年間對我國21省市羊肚菌資源進行了廣泛野外調(diào)查和采集,積累標(biāo)本900余份,,在形態(tài)學(xué)研究基礎(chǔ)上,,對其中的361份進行了ITS測序,據(jù)此篩選出可能為不同物種的代表標(biāo)本70份,。利用另外4個分子標(biāo)記對它們進行了測序,,結(jié)合業(yè)已發(fā)表的有關(guān)序列,與美國農(nóng)業(yè)部O’Donnell實驗室合作,,采用新近流行的分析方法,,對羊肚菌屬的物種多樣性、起源時間,、分布格局,、擴散路線和演化歷史進行了研究。部分研究成果已在真菌學(xué)主流期刊Fungal Genetics and Biology在線發(fā)表,。
該文的主要新意在于:發(fā)現(xiàn)中國共有30個羊肚菌物種,,其中20種迄今僅見于中國,11種為新物種,,中國的物種比整個歐洲的或北美的都多,,提出東亞或中國是羊肚菌屬的現(xiàn)代物種多樣性中心;羊肚菌屬可能在晚侏羅紀(jì)至早白堊紀(jì)時起源于北美西部,,多數(shù)物種可能通過白令陸橋傳播至亞洲,,并且歐亞物種之間進行過交流和擴散,;晚中新世時,干旱和氣候的變化導(dǎo)致了北美和歐洲兩地區(qū)部分物種滅絕,,生境的片斷化引起部分異域物種形成,;青藏高原隆升與物種分化有密切聯(lián)系,東亞約90%的物種是自中中新世至今分化出來的(見附圖),。
該研究得到NSFC-云南聯(lián)合基金重點項目(U0836604),、國家重點基礎(chǔ)研究發(fā)展計劃(2009CB522300)等的資助。(生物谷Bioon.com)
doi:10.1016/j.fgb.2012.03.006
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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.