High density, Multi-population Consensus Genetic Linkage Map for Peach (Prunus persica L. Batsch)

Highly saturated genetic linkage maps are extremely helpful to breeders and are essential prerequisite for a number of biological applications, such as the identification of marker-trait associations, mapping quantitative trait loci (QTL), candidate gene identification, the development of molecular markers for marker-assisted selection (MAS), and association and comparative genetic studies. Several high density inter- and intraspecific genetic maps, constructed using 9K SNP peach array, are available for peach. However, these genetic maps are based on single mapping population and have limited use for QTL discovery and comparative studies. A consensus genetic linkage maps developed from multiple different populations provide not only a higher marker density and a greater genome coverage when compared to the individual maps, but also serve as valuable tools for estimating genetic positions of unmapped markers. In this study, four high density intraspecific Prunus persica genetic maps, ‘O’Henry’ × ‘Clayton’ (OC²), PI91459 (‘NJ Weeping’) × ‘Bounty’ (WB), ‘Venus’ × ‘Venus’ (VV), and updated ‘Zin Dai’ × ‘Crimson Lady’ (ZC²), and interspecific ‘Texas’ × ‘Earlygold’ (T × E) map were used for the development of a consensus genetic linkage map for peach. The consensus linkage map contains a total of 4,015 molecular markers, consisting of 9 SSRs, 4,005 SNPs and 1 morphological marker associated with slow ripening in peach. The map spans a genetic distance of 844.8 cM with an average marker density of 0.7 cM/marker. This consensus genetic linkage map represents the most comprehensive peach map available to date and will serve as a new reference map for the Prunus genus. It will support QTL identification and molecular marker development for peach and other genetic studies within the Rosaceae.