Developing the Genomic Infrastructure for Breeding Black Raspberry

Over the last 75 years, the black raspberry (Rubus occidentalis L.) industry in the United States has steadily declined due to a lack of adapted and disease resistant cultivars. The high anthocyanin content of black raspberry and associated health benefits have revived interest in production and breeding new cultivars. Wild black raspberries were recently collected in their native range from more than 130 locations across 27 U.S. states and two Canadian provinces. Evaluation of this wild germplasm led to the identification of four sources of aphid resistance, two of which were introgressed into the elite breeding pool in two mapping populations. Funding was recently obtained from the USDA’s Specialty Crops Research Initiative (SCRI) to develop the genomic infrastructure for breeding improved black raspberries. The objectives of this project include: 1) the development of genomic tools for breeding black raspberry; 2) maintaining or enhancing primary and secondary metabolites in selections; and 3) assessment of consumer preferences and identification of factors that can enhance fresh and processing market expansion. We have begun constructing a linkage map, assembling a draft genome, and generating new microsatellite markers and EST sequences from different black raspberry tissues. The mapping populations have been propagated and will be planted in four different production regions across North America. Phenotypic and genotypic information will be used to identify quantitative trait loci important for breeding objectives. The results will inform decisions regarding germplasm value and usage, crossing, and selection through marker-assisted breeding and phytochemical quality, and will be useful for breeding programs across the U.S.