Peach flavor is influenced by a delicate balance of sugar, acid content, and aromatic volatiles. Developing flavorful peaches is a high priority for breeding programs; however, obtaining the optimum combination of these desirable taste attributes has been challenging as their genetic control is complex. A series of studies have identified a region on peach chromosome 4 that contains genes with genetic variation for sugar and acid levels in peach breeding germplasm. In particular, this region was identified in multiple populations over multiple years based on evaluations of three sugars (fructose, glucose and sorbitol) and three acids (malic, citric and quinic) (Quilot et al. 2004; Dirlewanger et al. 2006).

With genetic knowledge of the functional variants for this chromosome 4 trait locus in their plant material, breeders can begin to predict the fruit taste attributes of their breeding materials resulting in more efficient crosses.