利用植物DNA条形码构建亚热带森林群落系统发育关系——以鼎湖山样地为例

在群落水平上重建植物系统发育关系是当前植物系统学研究的一项重要内容；DNA条形码技术的出现为这一工作的开展提供了便利。本文选取国际通用的植物DNA条形码（rbcL，matK和psbA trnH），对鼎湖山大样地的183个物种（隶属于24目51科110属）进行测序；分别利用两位点和三位点DNA条形码组合构建该样地植物群落的系统发育关系，并比较不同位点组合构建出的群落系统发育关系的拓扑结构和节点支持率；最后选出一个具有最好拓扑结构和最高节点支持率的鼎湖山大样地群落系统发育关系。在目、科和属这三个水平上，三位点条形码片段组合构建的群落系统发育关系与APG系统获得较好匹配；有些进化分支在相应的APG系统位置解决得不好，却在条形码序列构建的系统发育关系中得到了较好解决。表明综合使用不同进化速率的DNA条形码片段并采取三位点超级矩阵的组合策略，在未采用APG系统大框架的情况下，也能快速而又相对准确地构建出鼎湖山南亚热带森林植物群落的系统发育关系。

Building a Subtropical Forest Community Phylogeny Based on Plant DNA Barcodes from Dinghushan Plot

Reconstructing phylogenies at the community scale remains a fundamental but important work for current researches related to plant systematics, which can be facilitated due to the arising of plant DNA barcodes. We sampled, sequenced, and employed matK, rbcL and psbA-trnH to generate a multi-locus barcode for 20-ha Dinghushan subtropical forest dynamics plot, with 183 angiosperm species belonging to 110 genera (51 families from 24 orders) in South China. Compared to the two-locus barcode (rbcL+matK , and rbcL+psbA-trnH), the supermatrix of three barcode loci discriminated most of closed related taxa and generated a better-resolved community phylogeny utilizing an unconstraint approach in the Dinghushan plot, providing a first case that a subtropical forest plot with similarly limited taxon sampling with fewer orders and families could also provide significant congruence to the overall angiosperm phylogeny.