RAPD analysis of genetic variation between a group of rose cultivars and selected wild rose species

The genetic variability based on random-amplified polymorphic DNA markers was analysed among 10 cultivated rose varieties and 9 wild species from three different series of the genus Rosa. Using 13 different RAPD primers, 104 polymorphic DNA fragments with a high potential to differentiate rose genotypes could be produced. A dendrogram displaying the relative genetic similarities among the genotypes shows the existence of large genetic diversity among the cultivated roses as compared to the wild species. Furthermore, the main clusters found here are in agreement with known pedigrees and the classical taxonomy. However, the relationships between cultivated roses as inferred by RAPD markers do not correlate with the classical rose classification system. From the present data it is concluded that cultivated roses display a high level of genetic variability despite the fact that single morphological and physiological characters may be less polymorphic within rose groups. This contrasts with the widely accepted opinion of a lack of genetic variability in roses. This is also in accordance with the reported history of rose breeding which makes it highly probable that rose genomes comprise mosaics of different species genomes. As a consequence, it may be possible to utilize the high genetic variability of all genetic traits not under actual selection by breeders for future breeding programmes.