記者從中科院華南植物園獲悉,，該園科學(xué)家近日在粵發(fā)現(xiàn)了蘭科植物新屬種——丹霞蘭。業(yè)內(nèi)專家表示,，該蘭花獨特的種子結(jié)構(gòu)和唇瓣結(jié)構(gòu)為針對蘭科植物的進(jìn)化生物學(xué)研究提供了一個新的方向,。研究論文“蘭科植物新屬——丹霞蘭屬，及布袋蘭族的系統(tǒng)學(xué)研究”近期已刊于美國《公共科學(xué)圖書館·綜合》,。
華南植物園物種多樣性和保育研究組博士翟俊文在導(dǎo)師邢福武研究員和深圳市蘭科植物保護研究中心教授劉仲健的指導(dǎo)及仁化縣政府研究團隊的共同努力下,，在廣東韶關(guān)丹霞山發(fā)現(xiàn)了一種具有獨特結(jié)構(gòu)的腐生蘭花。經(jīng)過解剖學(xué),、孢粉學(xué)和分子生物學(xué)等研究,，研究人員確定該蘭花是一個新物種，將其命名為“丹霞蘭”,，同時又以丹霞蘭成立了蘭科的一個新屬——丹霞蘭屬,，并確定其系統(tǒng)位置，完成了其所在的布袋蘭族系統(tǒng)學(xué)研究,。
研究人員表示,，蘭科植物的種子多呈灰塵狀，偶見顆粒狀,，大小不超過1毫米,，而丹霞蘭的種子長達(dá)2毫米，直徑可達(dá)1毫米,，這是首次在蘭科植物中發(fā)現(xiàn)有如此之大的種子,。
研究表明,，這個奇特的蘭花與寬距蘭屬的寬距蘭親緣關(guān)系最為接近，同屬于蘭科樹蘭亞科布袋蘭族寬距蘭亞族,，其因獨特的種子結(jié)構(gòu),、唇瓣基部雙囊狀的結(jié)構(gòu)和唇瓣上“Y”形的附屬物而區(qū)別于其他蘭科植物。（生物谷Bioon.com）
doi: 10.1371/journal.pone.0060371
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A new orchid genus, danxiaorchis, and phylogenetic analysis of the tribe calypsoeae
Zhai JW, Zhang GQ, Chen LJ, Xiao XJ, Liu KW, Tsai WC, Hsiao YY, Tian HZ, Zhu JQ, Wang MN, Wang FG, Xing FW, Liu ZJ
BACKGROUND: Orchids have numerous species, and their speciation rates are presumed to be exceptionally high, suggesting that orchids are continuously and actively evolving. The wide diversity of orchids has attracted the interest of evolutionary biologists. In this study, a new orchid was discovered on Danxia Mountain in Guangdong, China. However, the phylogenetic clarification of this new orchid requires further molecular, morphological, and phytogeographic analyses. METHODOLOGYPRINCIPAL FINDINGS: A new orchid possesses a labellum with a large Y-shaped callus and two sacs at the base, and cylindrical, fleshy seeds, which make it distinct from all known orchid genera. Phylogenetic methods were applied to a matrix of morphological and molecular characters based on the fragments of the nuclear internal transcribed spacer, chloroplast matK, and rbcL genes of Orchidaceae (74 genera) and Calypsoeae (13 genera). The strict consensus Bayesian inference phylogram strongly supports the division of the Calypsoeae alliance (not including Dactylostalix and Ephippianthus) into seven clades with 11 genera. The sequence data of each species and the morphological characters of each genus were combined into a single dataset. The inferred Bayesian phylogram supports the division of the 13 genera of Calypsoeae into four clades with 13 subclades (genera). Based on the results of our phylogenetic analyses, Calypsoeae, under which the new orchid is classified, represents an independent lineage in the Epidendroideae subfamily. CONCLUSIONS: Analyses of the combined datasets using Bayesian methods revealed strong evidence that Calypsoeae is a monophyletic tribe consisting of eight well-supported clades with 13 subclades (genera), which are all in agreement with the phytogeography of Calypsoeae. The Danxia orchid represents an independent lineage under the tribe Calypsoeae of the subfamily Epidendroideae. This lineage should be treated as a new genus, which we have named Danxiaorchis, that is parallel to Yoania. Both genera are placed under the subtribe Yoaniinae.
