SSR FINGERPRINTING OF BLACK RASPBERRY CULTIVARS SHOWS DISCREPANCIES IN IDENTIFICATION
Breeding progress in black raspberry (Rubus occidentalis L.) has been limited by a lack of genetic diversity in elite germplasm. Black raspberry cultivars are noted for showing very few differences, and seedlings for a lack of segregation for important traits. Genetic fingerprinting using microsatellite, or simple sequence repeat (SSR) markers, can reliably identify unique clones and evaluate diversity in black raspberry cultivars. Twenty-one black raspberry cultivars were sampled from the USDA-ARS National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon. Black raspberry clones were also sampled from nurseries, growers fields, and other black raspberry breeding programs for comparison. These genotypes were compared using 18 polymorphic SSR primer pairs. The black raspberries Bristol, Jewel, and Mac Black had consistent SSR fingerprints between sources. However, plants being sold as Black Hawk and Cumberland had the same fingerprint as Jewel. Plants of Bristol, Cumberland, Munger, New Logan, Plum Farmer and Shuttleworth in the NCGR collection had identical fingerprints. Eleven unique SSR fingerprints were found among plants being grown or sold as Munger, though there was one predominant fingerprint for this cultivar. Allen and John Robertson were each represented by three different fingerprints from three different sources, and Earlysweet and Jewel had SSR alleles at multiple loci that cannot be explained by their reported pedigrees. While overall genetic diversity in black raspberry cultivars is low, discrepancies in the naming of clones appear to be widespread in commercial and research plantings. Future work in this area should focus on sampling additional independent sources of plant material and evaluating clones to determine the extent of performance differences. Further SSR development in black raspberry may be needed to fingerprint some unique clones.
Dossett, M., Bassil, N.V. and Finn, C.E. (2012). SSR FINGERPRINTING OF BLACK RASPBERRY CULTIVARS SHOWS DISCREPANCIES IN IDENTIFICATION. Acta Hortic. 946, 49-53
Rubus occidentalis, microsatellite, simple sequence repeats, DNA markers