Genetic characterization of raspberry cultivars using molecular markers

Molecular (DNA) markers have some advantages over morphological markers for identification purposes and for estimating genetic diversity. In this study we have used two types of molecular markers to characterize a collection of 36 raspberry cultivars: Ten RAPD primers and seven microsatellite (SSR) loci were used. The collection included commercial cultivars, very closely related because some cultivars have been recurrently used in many breeding programs. Even though, both kind of markers (RAPD and SSR) could distinguish all cultivars, although SSR data showed higher polymorphism than RAPD data. Since this and for other reasons (simplicity, possibility of automation, multiplexation, etc.), microsatellite markers are preferable. Cluster analysis using RAPD and SSR data was used to examine genetic relationships within the collection. Results closely resembled pedigree relations between cultivars, and cultivars with similar origins or belonging to the same breeding program were grouped together in the same cluster. The obtained results confirmed the utility of RAPD and SSR markers to discriminate among closely related raspberries and to determine the genetic diversity among cultivars. This information is useful for germplasm characterization and identification of cultivars, including legal issues like assessing infringements on plant breeders' rights.