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

Abstract

The tea-scented China roses largely correspond to the three recognized double-petaled Rosa odorata (Andrews) Sweet (Rosoideae, Rosaceae) varieties, which are the ancestors of modern hybrid tea roses and had a definite and permanent influence on the evolution of modern garden roses. Here the hypothesis of a hybrid origin of the tea-scented China roses between R. odorata var. gigantea and R. chinensis was tested. Two single-copy nuclear genes of the cytosolic glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and the chloroplast-expressed glutamine synthetase (ncpGS) together with two plastid loci (trnL-F and psbA-trnH) were sequenced for representative accessions of four R. odorata varieties, R. chinensis, and 28 other Rosa species. Phylogenetic relationships were estimated from two nuclear loci using maximum parsimony and Bayesian analyses, and a haplotype network was constructed on the combined plastid data using NETWORK. For GAPDH and ncpGS loci, the clonal sequences of the three double-petaled varieties were clustered into two clades, one clade with R. odorata var. gigantea, and the other with partial sequences of R. chinensis, which suggested that the tea-scented China roses were hybrids between R. odorata var. gigantea and R. chinensis. Two plastid loci suggested that R. odorata var. gigantea could be the maternal parent and R. chinensis the paternal parent.

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.…”

“…Chinenses and Synstylae. However, hybridization seems to be at work in these two sections as suggested by previous studies (Ohba et al, 2000;Meng et al, 2011) and numerous intermediate morphological characters from specimens and field observations.…”

“…In addition, Rosa lucidissima has a unique character consisting of congested bristles on branchlets, pedicels and receptacles. Because this section includes important garden plants or wild ancestors of cultivated roses, research on this section has been prolific (see Meng et al, 2011;Scalliet et al, 2008;Scariot et al, 2006), but most studies focused on the garden roses or double-petaled varieties. In this study, we sampled all three wild taxa and double-petaled R. odorata (Andrews) Sweet var.…”

A high-quality sequence ofRosa chinensisto elucidate genome structure and ornamental traits

“…spontanea and R . x odorata var gigantea [6], consistent with the relatively low sequence divergence of R. chinensis var. spontanea compared to the HapOB reference sequence.…”

“…Roses present an ideal model for woody and ornamental plants, but also display a range of unique features thanks to their complex evolutionary history including interspecific hybridization events and polyploidisation [4–6]. Roses belong to the genus Rosa (Rosoideae, Rosaceae) , which contains more than 150 species [7] with varying levels of ploidy, ranging from 2n=2× to 10× [8, 9].…”