Construction of a mega-scale molecular phylogenetic tree and establishment of a new taxonomic system based on both morphological and molecular data of the monocotyledons

利用陆地植物DNA条形码推荐基因matK的序列，对931属1006份样品进行简约性分析，构建单子叶植物大尺度系统发育树，并从系统发育树分辨率的角度评价matK在单子叶植物属间的区分能力。247，500棵同样最简约的树的严格一致性包括695个二叉分支和99个多叉分支。也就是说，大约88%的分支是二分的。严格共识树包括236个进化枝（约所有进化枝的30%），其接收100%引导支持，以及198个进化枝（约所有进化枝的25%），其接收90%-99%引导支持。因此，严格共识树很好地解决了单子叶植物的遗传问题，尽管它是一个由1000多个样本组成的巨型树。matK的辨别力在单子叶植物中得到证实。该巨型系统树的基本框架与早期的单子叶植物系统树基本一致。

Using sequences of plastid matK, which was one of the genes recommended as a DNA barcode for land plants, from 1006 samples of 931 genera, we conducted a parsimony analysis to construct a mega-scale phylogenetic tree of the monocots and to evaluate discriminatory power of the matK among monocot genera from the angle of resolution of the phylogenetic tree. Strict consensus of 247,500 equally most parsimonious trees comprises 695 dichotomous branchings and 99 polychotomous branchings. That is, about 88% of branchings is dichotomous. The strict consensus tree includes 236 clades (about 30% of all the clades) that receive 100% bootstrap support and 198 clades (about 25% of all the clades) that receive 90%-99% bootstrap support. Thus, the strict consensus tree resolved the phylogeny of the monocots well, although it is a mega-scale tree composed of more than 1000 samples. Discriminatory power of the matK was confirmed in the monocots. The basic frame of the present mega-scale phylogenetic tree of the monocots well agrees to earlier monocot phylogenetic trees.