Specialists studying the genus Viola have consistently allied the Hawaiian violets comprising section Nosphinium--most of which are subshrubs or treelets--with putatively primitive subshrubs in certain South American violet groups. Hawaiian violets also possess inflorescences, a floral disposition otherwise found only in other genera of the Violaceae, thus strengthening the hypothesis of a very ancient origin for the Hawaiian species. A survey of phylogenetic relationships among infrageneric groups of Viola worldwide using nuclear rDNA internal transcribed spacer (ITS) sequences revealed a dramatically different biogeographic origin for the Hawaiian violets: A monophyletic Hawaiian clade was placed in a close sister relationship with the amphi-Beringian tundra violet, V. langsdorffii s. 1., in a highly derived position. This remarkable and unforeseen relationship received strong clade support values across analyses, and monophyly of the Hawaiian lineage was further indicated by a unique 26-base-pair deletion in section Nosphinium. The high polyploid base chromosome number (n approximately equal to 40) in the Hawaiian violets relates them to Alaskan and eastern Siberian populations in the polyploid V. langsdorffii complex. More than 50 species of the 260 allochthonous birds wintering in the Hawaiian Islands are found to breed in the Arctic, occupying habitats in which individual birds might have encountered ancestral V. langsdorffii populations and served as dispersers to the central Pacific region. Acquisition of derived morphological traits (e.g., arborescence and inflorescences), significance of a confirmed Arctic origin for a component of the Hawaiian flora, and the likelihood of other "cryptic" Arctic elements in the Hawaiian flora deserving independent molecular phylogenetic corroboration are discussed.

译文

:研究中提琴属的专家一直将组成Nosphinium的夏威夷紫罗兰(大部分是亚灌木或小乔木)与某些南美紫罗兰组中的原始亚灌木联系在一起。夏威夷紫罗兰还具有花序,否则只能在紫堇科的其他属中发现花序,因此加强了夏威夷物种起源很久的假设。使用核内rDNA内部转录间隔区(ITS)序列对世界各地中提琴中下属群体之间的系统发生关系进行的调查显示,夏威夷紫罗兰的生物地理起源存在显着不同:单系夏威夷进化枝与两栖类-柏林苔原紫罗兰有着密切的姐妹关系。 ,V. langsdorffii s。 1.处于高度派生的位置。这种惊人的,不可预见的关系在整个分析中都得到了强有力的进化支支持价值,夏威夷血统的单亲性在Nosphinium部分中独特的26个碱基对的缺失进一步表明了这一点。夏威夷紫罗兰中较高的多倍体基本染色体数目(n约等于40)使它们与多倍体郎氏多菌复合体中的阿拉斯加和西伯利亚东部种群有关。在夏威夷群岛越冬的260只异形鸟类中,有50多种在北极繁殖,它们栖息的栖息地中个别鸟类可能曾遇到过郎氏多氏菌祖先种群,并成为中太平洋地区的传播者。讨论了衍生形态特征的获取(例如乔木和花序),确定的夏威夷起源对于夏威夷植物区系组成部分的意义以及夏威夷植物区系中其他“隐秘”北极元素是否值得独立分子系统发育确证的可能性。

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