The genus Rosa (Rosoideae, Rosaceae) revisited: molecular analysis of nrITS-1 and atpB-rbcL intergenic spacer (IGS) versus conventional taxonomy

Abstract

The genus Rosa (Rosoideae, Rosaceae) revisited: molecular analysis of nrITS-1 and atp B-rbc L intergenic spacer (IGS) versus conventional taxonomy Sequences of the nrDNA internal transcribed spacer 1 (nrITS-1) and atp B-rbc L intergenic spacer (IGS) of the cpDNA were analysed for all sections of the genus Rosa L. (Rosoideae, Rosaceae) to study molecular infrageneric taxonomy and relationships of Rosa with respect to conventional taxonomy based upon morphological and anatomical data as well as phytochemical characters. The results suggest that Rosa in its traditional infrageneric circumscription is not reflected by molecular data. Cinnamomeae , Carolinae and Pimpinellifoliae are not monophyletic based on the molecular data and this is mirrored in conventional taxonomy that separates these sections by weak morphological characters such as sepal performance, existence of bracts, and number of flowers per inflorescence. Section Pimpinellifoliae is split by the monotypic sections Laevigatae , Platyrhodon , Bracteatae and Hesperhodos . Section Caninae is a natural allopolyploid group characterized by its autapomorphic ITS C-type and Canina-meiosis. CpDNA subdivides sect. Caninae into two natural clusters of eglandular and glandular species. NrITS shows sect. Synstylae / Indicae to be the direct sister group to sect. Caninae , not Rosa ( Gallicanae ) although both groups are morphologically characterized by pinnate sepals. From our molecular data sect. Indicae and sect. Synstylae are consectional. The highest taxonomic rank below the generic level should be the sectional status.

Phylogeny of Rosa sections Chinenses and Synstylae (Rosaceae) based on chloroplast and nuclear markers

“…4 and 5). This relationship was also recovered in previous studies (Bruneau et al, 2007;Fougère-Danezan et al, 2015;Meng et al, 2011;Qiu et al, 2012;Wissemann and Ritz, 2005). Our phylogenies showed that these species together are not monophyletic, and chloroplast phylogeny resolved R. lucidissima as the earliest divergent species in the Asian subclade.…”

“…Though this study focused on sections Chinenses and Synstylae, our extensive sampling did help understanding relationships within the whole genus. As previous studies found (Bruneau et al, 2007;Wissemann and Ritz, 2005;Wu et al, 2000), none of our three phylogenies (Figs. 1-3) supported traditional taxonomy of subgenera and sections (Rehder, 1940;Wissemann, 2003).…”

Untangling the hybrid origin of the Chinese tea roses: evidence from DNA sequences of single-copy nuclear and chloroplast genes

“…Five of the seven major wild ancestors of garden roses (Wylie 1954) were also sampled in this study. Because the phylogenetic relationships among species of Rosa have not yet been fully resolved (Wissemann and Ritz 2005;Bruneau et al 2007), 30 species of Rosa in total were sampled to avoid missing the real parental species, covering eight of the ten sections of subgen. Rosa and one species from subgen.…”

“…The barriers to gene flow among Rosa L. species are weak (Atienza et al 2005), and hybridization has contributed greatly to species diversity of this genus (Rehder 1940;Wissemann and Ritz 2005). Numerous fertile interspecific rose hybrids have been reported (Fagerlind 1944(Fagerlind , 1951(Fagerlind , 1958Grustafsson 1944;Lewis and Basye 1961;Roberts 1977;Atienza et al 2005;Bruun 2005;Mercure and Bruneau 2008).…”

Genetic mapping in polyploids

“…The genus Rosa consists of a highly complex and much-debated phylogeny, divided into four subgenera, of which subgenus Rosa comprises over 95% of all species (Wissemann and Ritz, 2005). Rosa is generally divided into ten sections, four of which (Synstylae, Gallicanae, Indicae and Pimpinellifoliae) have contributed to the domesticated rose genepool .…”