Mapping a major gene for red skin color suppression (highlighter) in peach

Presence, absence and intensity of red skin color in peach fruit are key characters for breeding varieties adapted to different market niches and consumer preferences. Red skin color is the result of anthocyanins, and in some progenies, the suppression of red skin color has been found to be controlled by a single gene, H/h, where plants homozygous for the recessive allele (h) produce the highlighter (anthocyaninless) phenotype. In this paper we analyzed an F2 population of 276 individuals segregating for this trait and mapped the H gene on a 5 cM region of linkage group 3. This region was saturated with additional markers and finally H was located in a genomic region of ~607 kbp containing 62 genes. Three of these genes corresponded to MYB10 transcription factors, known to control anthocyan biosynthetic pathways in peach and other species, such as cherry and apple. A codominant marker based on the sequence of one of these genes (PpMYB10.1) was used to genotype the F2 progeny and cosegregated with the trait. To further validate the marker it was tested in a collection of 87 peach cultivars. A strong association was found between the marker genotype and the intensity of red blush, with the three cultivars that have a complete absence of red blush being homozygous for the marker allele associated with the highlighter trait, confirming that it could be used as an efficient, although not diagnostic, marker to select this character in peach breeding programs.