Phylogenetic relationship in the genus Rosa based on the restriction enzyme analysis of the chloroplast DNA

To plot the phylogenetic relationship within the genus Rosa, we compared th e restriction sites of chloroplast DNAs among 32 species. With the use of 1 4 restriction endonucleases, restriction fragment patterns of cpDNAs were o btained from 32 lines of Rosa species and compared with each other. Three h undred thirty-five restriction sites were surveyed. Thirty-three sites were phylogenetically informative. Among the chloroplast genome types, 18 prima ry groups are formed. The majority rule consensus tree established by the W agner parsimony method indicated that the species in sections Synstylase an d Indica, and sections Carolinae and Cinnamomeae belong to a monophyletic c lade, which agrees with the morphological classification, Sections Carolina e, Cinnamomeae, and Pimpinelifoliae lie distantly from the other sections, suggesting that these sections may have differentiated in an early stage of evolution followed by the appearance of other sections. A comparison of th e previous classification of Rosa species with that in this study, revealed several discrepancies. R. gigantea, R. moschata, and R. damascena, which a ppear to be monophyletic, were grouped into one cluster apart from section Gallicanae, to which R, damascena was formerly classified. The present mole cular data indicate that the maternal ancestor of R. centifolia 'Japonica' may be R, canina. It is proposed that R. roxburghiin and R. roxburghiin hir tula are separated, based on their differences in cpDNA. Interspecific cpDN A variation is common, a great deal of variability was detected in Rosa. Ex cessive dependence on one particular cytoplasm may be undesirable, we sugge st that the methods described in this paper be used to survey the cytoplasm ic base of modern rose cultivars.