Reticulate or tree-like chloroplast DNA evolution in Sileneae (Caryophyllaceae)?
Reticulate or tree-like chloroplast DNA evolution in Sileneae (Caryophyllaceae)?
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DOI：
10.1016/j.ympev.2008.04.015
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发表时间：
2008-07-01
影响因子：
4.1
通讯作者：
Oxelman, Bengt
中科院分区：
文献类型：
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作者：
Erixon, Per;Oxelman, Bengt
尽管采样的叶绿体DNA序列的25 kb的24个种在Sileneae的一些节点的系统发育仍然支持不足，它是不期望额外的序列采样将收敛到一个可靠的系统发育假说在这些部分的树。其主要原因可能是快速辐射和替代率的不均匀性。在密切相关的物种之间的分辨率差，往往解释为低水平的叶绿体数据的变化，但我们的数据的问题似乎是高水平的同质性。树状的叶绿体DNA进化不能被拒绝，但不同地区之间的明显的不一致模式进行了评估与古老的种间叶绿体重组的可能性作为解释模型。然而，几个主要的系统发育关系，以前没有认识到，有信心解决，例如两个西南安纳托利亚分类群S。cryptoneura和S. sordida强烈反对先前关于核DNA序列数据的研究，并指出了一个可能的同源倍体杂交起源的情况。与之密切相关的S. atocioides和S. aegyptiaca与Lychnis和Silene的其余部分形成姐妹群，因此表明Silene可能是并系的，尽管最近基于分子数据进行了修订。(C)2008年爱思唯尔公司All rights reserved.
Despite sampling of up to 25 kb of chloroplast DNA sequence from 24 species in Sileneae a number of nodes in the phylogeny remain poorly supported and it is not expected that additional sequence sampling will converge to a reliable phylogenetic hypothesis in these parts of the tree. The main reason for this is probably a combination of rapid radiation and substitution rate heterogeneity. Poor resolution among closely related species are often explained by low levels of variation in chloroplast data, but the problem with our data appear to be high levels of homoplasy. Tree-like cpDNA evolution cannot be rejected, but apparent incongruent patterns between different regions are evaluated with the possibility of ancient interspecific chloroplast recombination as explanatory model. However, several major phylogenetic relationships, previously not recognized, are confidently resolved, e.g. the grouping of the two SW Anatolian taxa S. cryptoneura and S. sordida strongly disagrees with previous studies on nuclear DNA sequence data, and indicate a possible case of homoploid hybrid origin. The closely related S. atocioides and S. aegyptiaca form a sister group to Lychnis and the rest of Silene, thus suggesting that Silene may be paraphyletic, despite recent revisions based on molecular data. (C) 2008 Elsevier Inc. All rights reserved.