Phylogenetic Relationships in the Genus Rosa Revisited Based on rpl16, trnL-F, and atpB-rbcL Sequences

Abstract

Three chloroplast DNA (cpDNA) sequences [the rpl16 intron, the trnL-F, and atpB-rbcL intergenic spacer (IGS)] were employed to study phylogenetic relationships in the genus Rosa. Phylogenetic analyses using these three concatenated sequences were performed using maximum parsimony (MP) and Bayesian inference (BI) methods. Both analyses results suggest that the molecular phylogeny conforms closely to the conventional classification of botanical sections. Morphological similarities between R. sects. Synstylae and Chinenses, and R. sects. Rosa and Carolinae are corroborated on the molecular level in our analyses. Four taxa from R. sect. Pimpinellifoliae are further divided into two small clades, which reflect the morphological characters for these species on a molecular level. Whereas three accessions of R. foetida from R. sect. Pimpinellifoliae form a separate clade. R. ×fortuniana forms a clade with R. laevigata based on its maternal inheritance of cpDNA. R. ×cooperii is hypothesized to be a hybrid with seed parent from R. sects. Synstylae and Chinenses. And R. roxburghii should be classified as a section within the R. subgen. Rosa, rather than being treated as its own subgenus, based on molecular analyses.