Blackberry Markers and Their Application to Fingerprinting and Gene Identification

Cultivated blackberry is bred to display traits such as increased fruit size, yield, pathogen resistance, primocane fruiting, and pricklelessness. Molecular marker applications in blackberry are still in their infancy, but recent work has shown advancement in the areas of fingerprinting and microsatellite marker design.  However, a standard set of blackberry fingerprinting markers has yet to be developed as well as the characterization of genes for important traits in blackberry.  We have employed a variety of molecular markers designed for crops closely related to blackberry to achieve two goals. First, we developed a set of ten microsatellite markers that are able to produce unique fingerprints of twenty blackberry cultivars. Fingerprint data derived from this study may provide a quick and relatively inexpensive way for breeders to identify cultivars in order to avoid excess homozygosity due to inbreeding and protect their intellectual property rights. Second, we identified genes that may be associated with prickle development in blackberry using bulked segregant analysis (BSA) and random markers. Information gained through the isolation of genes involved in prickle development may aid in future efforts toward marker-assisted selection in blackberry breeding and the development and early identification of prickleless blackberry cultivars.