The development of a genetic linkage map of blackcurrant (Ribes nigrum L.) and the identification of regions associated with key fruit quality and agronomic traits

The first genetic linkage map of blackcurrant (Ribes nigrum L.) was constructed using AFLP, SSR (genomic and EST-derived) and SNP markers, in a mapping population derived from two diverse breeding clones of blackcurrant from the SCRI breeding programme. Cluster analysis of the population revealed that the individuals within the population formed two distinct sub-populations, with segregation ratios consistent with one sub-population having the two intended parents, and the other being selfed segregants. The latter sub-population improves the map by providing a more informative estimate of recombination frequency than the crossed sub-population for some marker configurations, and also revealed the presence of two unlinked loci affecting viability. Several important phenological, agronomic and fruit quality traits were evaluated in the mapping population, and QTLs affecting these are located on the linkage map. This provides a framework for the development of marker-assisted breeding strategies for blackcurrant, to improve breeding efficiency and time to cultivar.