Molecular phylogenies of Udoteaceae (Bryopsidales, Chlorophyta) reveal nonmonophyly for Udotea, Penicillus and Chlorodesmis
Molecular phylogenies of Udoteaceae (Bryopsidales, Chlorophyta) reveal nonmonophyly for Udotea, Penicillus and Chlorodesmis
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DOI：
10.2216/i0031-8884-41-5-453.1
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发表时间：
2002-09
期刊：
影响因子：
1.6
通讯作者：
W. Kooistra
中科院分区：
文献类型：
--
作者：
W. Kooistra
摘要 由于不同性状组的证据相互矛盾，尤其是生殖结构和营养形态之间的证据相互矛盾，乌多亚科、青霉属、扇头象属和绿藻属内部和之间的通用划分仍然是临时的。这里提出的核糖体 DNA 系统发育与 Udoteaceae 内的经典属概念相矛盾，揭示了传统属是多系的。根据这项研究，据报道，青霉属的刷子本质上是一种无皮质的 Udotea 叶片，其中虹吸管失去了附着力。事实上，这种青霉形态独立出现两次。类似地，Chlorodesmis 的简单单轴叶状体是通过二次还原或幼态持续进化而来的。营养体菌体的虹吸解剖学并不能完美地描绘自然群体。然而，生殖结构的形状和大配子的大小似乎很好地限制了自然分类群。 Udotea 及其近缘物种 Chlorodesmis、Penicillus 和 Rhipocephalus 内的总体序列差异较低，表明谱系相对年轻且快速多样化。
Abstract Generic delineation within and among the udoteacean genera Udotea, Penicillus, Rhipocephalus and Chlorodesmis has remained provisional because of conflicting evidence from different sets of traits, especially between reproductive structures and vegetative morphology. The ribosomal DNA phylogeny presented here contradicts the classical generic concepts within the Udoteaceae by revealing traditional genera to be polyphyletic. Based on this study, it was reported that the brush of Penicillus is essentially an uncorticated Udotea blade in which siphons have lost adherence. In fact, this Penicillus morphology arises twice independently. Similarly, the simple uniaxial thallus of Chlorodesmis has evolved through secondary reduction or neoteny. Siphon anatomy of vegetative thalli does not delineate natural groups perfectly. However, the shape of reproductive structures and the size of macrogametes appear to circumscribe natural taxa well. Overall sequence divergence within Udotea and its allied species in Chlorodesmis, Penicillus and Rhipocephalus is low and indicates relatively young and rapidly diversifying lineages.