绣球属(Hydrangea L.)植物分子系统学及系统发育分析

该研究基于对绣球属(Hydrangea L.)的大尺度取样,选取国内外61种绣球属和近缘属植物,分别基于核基因片段(ITS)和叶绿体基因片段(rbcL,trnL-F,atpB)重建了绣球属及其近缘种属的系统发育关系。结果表明:(1)核基因与叶绿体基因树之间在树形上没有明显的冲突,进而基于核基因和叶绿体基因联合数据重建了绣球属及其近缘种属的系统发育关系。(2)基于联合数据构建的系统树确认了2个大分支,并得到了果实顶端截平与否这一形态学证据的强力支持;每个大分枝又分为4个类群,共确定了8个类群。部分类群也得到了广义宏观形态性状的支持,如第1类群得到了叶形、花粉以及种子形态的支持。因此,该系统发育关系的重建对于全面理解绣球属及其近缘种属的演化关系具有重要的启发。

Molecular Systematics and Phylogenetic Analysis of the Hydrangea (Hydrangeaceae)

In order to explore and reconstruct the phylogenetic relationships between Hydrangea and its related genera, we selected a total of 61 species from them on a global scale for the phylogenetic analysis based on the nuclear ribosomal internal transcribed spacer (ITS) and three chloroplast DNA fragments (rbcL, trnL F, atpB). Our results suggest that there is little difference between the phylogenetic trees based on the nuclear gene fragment and the chloroplast DNA fragments, respectively. As a result, by further analyzing the phylogenetic tree based on the combined dataset from both of them, two major clades in Hydrangea. We were identified, which were strongly supported by the morphological evidence that is whether the end of the fruit is truncated or not. Moreover, our results suggest that four groups were supported in each major clade and a total of eight groups were identified in Hydrangea. Some groups received strong support from generalized morphological characters. For instance, the first group was supported by morphological characters of leaf shapes, pollen grains and seed coats. Phylogenetic analyses conducted by this study shed new lights on the understanding of relationships among Hydrangea and its related genera.