Stone fruits (peach, apricot, European and Japanese plums and sweet and sour cherries) belong to the Prunus genus. According to Redher (1947) and Krüsmann (1978) this genus comprises respectively 77 or 140 wild and cultivated species, some economically important as sources of fruits, nuts, oil, rootstock, timber, and ornamentals. Redher divided Prunus into fi ve subgenera. Among them, the subgenus Prunophora contains plums (section Euprunus) and apricots (section Armeniaca), the subgenus Amygdalus includes peaches and almonds and the subgenus Cerasus, cherries. Of Asian origin,

1IRTA, Centre de Recerca en Agrigenòmica CSIC-IRTA-UAB-UB. Campus UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona, Spain. 2INRA, UR419, Unité de Recherches sur les Espèces Fruitières, BP 81, F-33140 Villenave d’Ornon, France. *Corresponding author: mariajose.aranzana@irta.cat

the centers of diversity of stone fruits are Eastern China (apricot, peach and P. salicina) and Central and Western Asia (almond, cherries, P. insititia, P. domesticaand P. cerasifera) from where they spread to Eastern Europe (Moore and Ballington 1991) (Table 3-1).