Phylogenetic analysis of Japanese Rosa species using matK sequences

The matK DNA was sequenced in each of the 15 Japanese Rosa taxa, 17 other A sian taxa, and two American taxa to analyse their phylogenetic relationship s. All the 14 tested taxa in the section Synstylae, associated with the sec tion Indicae, formed one clade. It was confirmed that sections Synstylae an d Indicae, with the common styles exserting from the hypanthium, are closel y related to each other. Furthermore, R. brunonii and R. moschata in the se ction Synstylae formed an inner clade which is consistent,vith their common morphological traits. Two clones of R. acicularis formed one single clade which was separated from the remaining species of the section Rosa. This fi nding suggests that R. acicularis might be a distinctive species in the sec tion Rosa. The remaining species of the section Rosa formed one clade which was further subdivided into two inner clades: R. rugosa and R. marretii fo rmed one clade, while R. acicularis var. nipponensis and R. willmottiae for med another clade. The distinctive relationship with R, acicularis implies that diploid R. acicularis var. nipponensis, traditionally treated as one v ariety of polyploid R. acicularis by some authors, is a primitive taxon and that it should be reassigned to its original specific rank as R. nipponens is.