A sweet cherry (Prunus avium L.) linkage map and its comparison to other prunus species
Résumé
The sweet cherry (Prunus avium) is one of the most popular temperate fruit crops. However, compared with others, such as the apple and peach, progress in breeding for improvement of sweet cherry has been slow. The long generation time and the large size of cherry trees severely limit the classical breeding method. Consequently, the integration of molecular markers in breeding programmes should be a powerful tool. Inheritance and linkage studies were conducted with microsatellite markers in an F, progeny including 133 individuals of a cross between 'Regina' and 'Lapins', which were chosen as parents for their distinct agronomic characters and especially because they allowed the study of resistance to fruit cracking, which is a limiting factor in sweet cherry production. 'Regina' is relatively resistant, and 'Lapins' is susceptible to fruit cracking. 'Lapins' is self-compatible, whereas 'Regina' is self-incompatible; moreover, they differ for several other characters: blooming and maturity dates, peduncle length, fruit colour, weight, firmness, titratable acidity and refractive index. These characters were measured at commercial and physiological maturity. For mapping, 337 Prunus microsatellites were tested for polymorphism: 249 (74%) give amplification, 76 were heterozygous in 'Regina', 63 in 'Lapins' and 44 in both parents. sMaps were constructed for each parent. The comparison of these cherry maps with other Prunus maps gives additional evidence for the high level of synteny within the Prunus genus. The two sweet cherry maps will be used for detection of QTLs involved in fruit quality.