The use of genomic data in the genetics of tetraploid roses across gene pools

The last few decades have seen tremendous progress in the development of genomic tools available for plant research and plant breeding. Sequenced genomes and next-generation sequencing-based tools have also greatly facilitated genetic, genomic and transcriptomic analyses of ornamentals. For roses major advances have been made with the publication of several whole genome sequences and the availability of high-throughput SNP markers. This has allowed the identification of large effect QTLs for a number of horticulturally important traits such as petal number, flower size and fragrance. Cultivated roses are a very diverse group of plants resulting from hybridization between several wild ancestors. Furthermore, breeding is carried out in more or less separate programmes and gene pools for garden, cut and pot roses. Here examples are presented of how markers closely associated with three major floral traits in garden roses can be successfully used for selection in cut roses. Furthermore, the suitability of selected SNP markers has been demonstrated in rose genetic resources comprising of more than 4,000 genotypes. This indicates that despite the enormous genetic diversity among cultivated roses genomic resources can be used across a wide range of genotypes for questions of marker-assisted selection, genotyping and genetic diversity analysis.