Genetic Mapping of Blooming Time in  Marcona ×  Fragnes's Population with Using Molecular Markers

Flowering time is an important horticultural trait in almond since it is essential to avoid the late frosts that affect production in early flowering cultivars. Evaluation of this complex trait is a long process because of the prolonged juvenile period of trees and the influence of environmental conditions affecting gene expression year by year. In this research flowering time was studied in an F1 almond progeny of 90 seedlings from the cross between the Marcona and the Fragness. In addition, a set of 63 co-dominant microsatellites or simple-sequence repeat (SSR) markers developed from peach, cherry and almond were used for the molecular characterization of the progeny. A genetic linkage map was created with 17 of these SSRs. Molecular studies at the DNA level confirmed this polygenic nature by identifying several genome regions (Quantitative Trait Loci, QTL) involved. QTL mapping detected two loci for flowering time (Ft-Q1 and Ft Q4) in Linkage groups 1 and 4 that close with BPPCT011 and UDP96-021 respectively. Finally, the development of efficient MAS strategies applied to almond and other Prunus breeding programs are also discussed.