Molecular characterization and relationship among wild and partially cultivated Rosa species

Abstract

Knowledge of population structure and genetic relationships within and among wild rose (Rosa spp.) genotypes is important to enhance its use in breeding and conservation. In the present study, we assessed the diversity among 21 wild roses belonging to 7 sections of subgenera Rosa, using morphological (14) and molecular markers (48). The neighbor-joining (NJ) tree clustered the species into two major and four minor clusters based on morphological similarity. Of the used SSRs, 31 SSRs were found to be polymorphic within selected genotypes. The matching co-efficient value calculated for each pair of species revealed the highest (0.91) and lowest (0.386) genetic similarity between species Rosa brunonii (Synstyle) - R. indica major (Indicae) and R. multiflora (Synstyle) - R. slancensis (Caninae). The phylogenetic chart obtained using molecular data clustered the genotypes in two major clusters. R. bourboniana exhibited a distant relationship with the remaining 20 genotypes and clustered separately. All the species from Gallicanae and most of the Indicae section species were clustered together and showed genetic similarities with each other. Significant variability was noticed among cultivated R. damascene selections. A local fragrant loose flower variant namely ‘Kakinada Red’ which is cultivated widely in southern peninsular India under tropical climate showed genetic nearness with Damascena cv. Ranisahiba. The Bayesian analysis conducted among genotypes showed three distinct genetic groups (ΔK=3). Concerning the genetic variability among different sections, highest and lowest variability values were observed with Synstyle and Pimpinellifoliae, respectively.