Research Article

Consistency between molecular phylogeny and morphological classification of the Salix matsudana Koidz. complex (Salicaceae)

Published: July 31, 2015
Genet. Mol. Res. 14 (3) : 8663-8671 DOI: 10.4238/2015.July.31.15

Abstract

The morphological species concept is based on morpho­logical traits, which are often subject to subjectivity or artifact. Molecular evidence is needed to test the reliability of morphological classification of taxa that are controversial and to provide appropriate taxonomic de­limitation. In this study, we used 15 single-copy nuclear loci and 2 chlo­roplast fragments to verify the morphological classification of the Salix matsudana Koidz. complex using phylogenetic approaches. Complete se­quence alignment showed slight diversification in nuclear sequences and no variety in chloroplast DNA fragments. Phylogenetic trees revealed a monophyletic group consisting of all individuals of S. matsudana and 2 clades within this group, with a 100% bootstrap support value and 1.00 posterior probability. The topology of the phylogenetic trees was highly consistent with the morphological classification of the S. matsudana com­plex. Verifying the genetic background of these classification units based on remarkable morphological differences will provide a foundation for future studies of Salix and the breeding of new horticultural varieties.

The morphological species concept is based on morpho­logical traits, which are often subject to subjectivity or artifact. Molecular evidence is needed to test the reliability of morphological classification of taxa that are controversial and to provide appropriate taxonomic de­limitation. In this study, we used 15 single-copy nuclear loci and 2 chlo­roplast fragments to verify the morphological classification of the Salix matsudana Koidz. complex using phylogenetic approaches. Complete se­quence alignment showed slight diversification in nuclear sequences and no variety in chloroplast DNA fragments. Phylogenetic trees revealed a monophyletic group consisting of all individuals of S. matsudana and 2 clades within this group, with a 100% bootstrap support value and 1.00 posterior probability. The topology of the phylogenetic trees was highly consistent with the morphological classification of the S. matsudana com­plex. Verifying the genetic background of these classification units based on remarkable morphological differences will provide a foundation for future studies of Salix and the breeding of new horticultural varieties.