Development of a second-generation genetic linkage map for peach [Prunus persica (L.) Batsch] and characterization of morphological traits affecting flower and fruit

An improved genetic linkage map was constructed from a peach Ferjalou Jalousia® × Fantasia (J×F) F₂ population. Ferjalou Jalousia® is a flat low-acidity clingstone peach, and Fantasia is a round, normally acidic freestone peach. This population is segregated for six Mendelian characters: pollen sterility, peach or nectarine fruit, flat or round fruit, clingstone, or freestone fruit. It also segregates for the D major gene controlling the fruit’s low acidity. A new character is reported here for the first time that segregates as a Mendelian character: trees bearing aborting fruits. These trees have flowers, but fruits start to fall 2 months after blooming. This recessive character has been named Af. We demonstrate that it is linked to the flat shape of the fruit. The previous map obtained from this cross was constructed using 63 individuals, whereas the present map was constructed using 207 individuals. Moreover, 82 simple-sequence repeat (SSR) markers, including 10 expressed sequence tag-SSRs, and 43 amplified fragment length polymorphism (AFLP) markers were added. Molecular markers linked to the six Mendelian characters were identified, and one of them has already been used for marker-assisted selection. This map will be used for detection of quantitative trait loci controlling organoleptic and nutritional fruit quality in peach.