Of the fruiting plant species, stone fruits are among the most important crops worldwide and play a signifi cant role in small farm agriculture and rural economies. They are comprised of the species in the genus Prunus in the family Rosaceae and are valued for their fruit, lumber and ornamental uses. Prior to the advent of molecular genetic technologies, our understanding of the genetics of the important traits in fruit tree breeding was extremely limited, however, with the application of molecular marker and genomics technologies, these species are rapidly becoming models for the study of fruit and forest tree genetics and genomics and for the discovery of genes critical to tree development and sustainability.