Advanced Genetic and Genomic Resources for the American Cranberry (Vaccinium macrocarpon Ait.)

The American cranberry (Vaccinium macrocarpon Ait.) is a small statured North American commercial fruit crop with a relatively short seed to seed period.   An improved genetic map comprising 12 linkage groups and totaling 1177.84 cM (i.e 96% of the estimated 470 Mb genome) has been constructed by genotyping two full-sib mapping populations using more than 600 simple sequence repeat (SSR) markers.  Furthermore, more than 373,639 single nucleotide polymorphisms (SNPs) within genomic scaffolds and predicted coding DNA sequences (CDS) have been identified using genotyping-by-sequencing and are being integrated into the SSR linkage map.  This linkage map is the most saturated in Vaccinium to date, and it will be the backbone of future QTL and GWAS studies that identify genomic regions linked or associated with important cranberry agronomic traits.  In fact, QTL have already been identified for average fruit weight, biennial bearing, total yield, total anothocyanin content, total soluble solids, and titratable acid within the two mapping populations.  Additionally, many of the positioned SSR markers are cross-transferable in other economically important Vaccinium species such as blueberries, lingonberries, huckleberries, and bilberries; and therefore, could be used in future comparative genomic studies and marker-assisted selection (MAS) strategies for introgressing species-specific traits through interspecific hybridization.  These genetic resources, when combined with the recently published preliminary nuclear genome and transcriptome and a high-throughput field-independent nursery system, could allow cranberry to become a model woody fruit crop for identification of candidate genes involved in fruit development, fruit physiology, and insect and disease defense pathways.