Molecular Phylogeny of Asian <i>Meconopsis</i> Based on Nuclear Ribosomal and Chloroplast DNA Sequence Data

<div><p>The taxonomy and phylogeny of Asian <i>Meconopsis</i> (Himalayan blue poppy) remain largely unresolved. We used the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) and the chloroplast DNA (cpDNA) <i>trnL-F</i> region for phylogenetic reconstruction of <i>Meconopsis</i> and its close relatives <i>Papaver</i>, <i>Roemeria</i>, and <i>Stylomecon</i>. We identified five main clades, which were well-supported in the gene trees reconstructed with the nrDNA ITS and cpDNA <i>trnL-F</i> sequences. We found that 41 species of Asian <i>Meconopsis</i> did not constitute a monophyletic clade, but formed two solid clades (I and V) separated in the phylogenetic tree by three clades (II, III and IV) of <i>Papaver</i> and its allies. Clade V includes only four Asian <i>Meconopsis</i> species, with the remaining 90 percent of Asian species included in clade I. In this core Asian <i>Meconopsis</i> clade, five subclades (Ia–Ie) were recognized in the nrDNA ITS tree. Three species (<i>Meconopsis discigera</i>, <i>M. pinnatifolia</i>, and <i>M. torquata</i>) of subgenus <i>Discogyne</i> were imbedded in subclade Ia, indicating that the present definition of subgenera in <i>Meconopsis</i> should be rejected. These subclades are inconsistent with any series or sections of the present classifications, suggesting that classifications of the genus should be completely revised. Finally, proposals for further revision of the genus <i>Meconopsis</i> were put forward based on molecular, morphological, and biogeographical evidences.</p>