Taxonomic status of Goodyera rosulacea (Orchidaceae): molecular evidence based on ITS and trnL sequences

Abstract

Goodyera rosulacea, which is morphologically similar to G. repens, is described recently as a new species based on its distinct morphological characters such as rosette-formed leaves, short rhizome and habitat. To verify the taxonomic identity of G. rosulacea and its taxonomic relationship within Korea Goodyera taxa, sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and the trnL region of cpDNA from 24 accessions including 1 outgroup accession were analyzed. Aligned sequences were analyzed using maximum parsimony and distance method, and the taxonomic identity and the taxonomic relationships among the related taxa were estimated by the existence of private marker gene and the phylogenetic tree of the aligned sequences. Morecular data indicate that G. rosulacea gas several private marker genes and shows monophyly in phylogenetic trees of both its and trnL sequences. the pairwise distance between G. rosulacea and the orher taxa of Korean Goodyera was 3.49-6.68% for ITS region and 5.05-9.53% for trnL region, indicating that G. rosulacea could be treated as an independent species. Therefore, our molecular data support the taxonomic of G. rosulacea as a distinct species of Korea. In phylogenetic trees, G. rosulacea formed same clade with G. repens, which has similar morphological characters with G. rosulacea, and showed the lowest pairwise distance with G. repens among Korean Goodyera taxa. These molecular data sugguested that G. rosulacea and G. repens are closely related taxa.