Fuertes Aguilar Javier, Nieto Feliner Gonzalo
Real Jardin Botánico, CSIC, Plaza de Murillo, 2, 28014 Madrid, Spain.
Mol Phylogenet Evol. 2003 Sep;28(3):430-47. doi: 10.1016/s1055-7903(02)00301-9.
A parsimony analysis of 133 sequences of the nuclear ribosomal DNA ITS1+5.8S+ITS2 region from 71 taxa in Armeria was carried out. The presence of additive polymorphic sites (APS; occurring in 14 accessions) fits the reticulate scenario proposed in previous work for explaining the ITS pattern of variation on a much smaller scale and is based mainly on the geographical structure of the data, irrespective of taxonomic boundaries. Despite the relatively low bootstrap values and large polytomies, part of which are likely due to disruptive effects of reticulation and concerted evolution in these multicopy sequences, the ITS analysis has phylogenetic and biogeographic implications. APS detected in this study are consistent with hypothesized hybridization events, although biased concerted evolution, previously documented in the genus, needs to be invoked for specific cases and may be responsible for a possible "sink" effect in terminals from a large clade. The causes for sequences of the same species appearing in different clades (here termed transclade) are discussed.
对海石竹属71个分类群的133条核糖体DNA ITS1 + 5.8S + ITS2区域序列进行了简约分析。添加多态性位点（APS；出现在14个样本中）的存在符合先前工作中提出的网状模式，该模式用于在更小尺度上解释ITS变异模式，并且主要基于数据的地理结构，而不考虑分类界限。尽管自展值相对较低且多歧分类较多，部分可能是由于这些多拷贝序列中的网状化和协同进化的干扰效应，但ITS分析具有系统发育和生物地理学意义。本研究中检测到的APS与假设的杂交事件一致，尽管该属先前记录的偏向性协同进化需要针对特定情况进行调用，并且可能是导致一个大分支终端出现可能的“汇”效应的原因。讨论了同一物种的序列出现在不同分支（这里称为跨分支）的原因。
