Identification of DNA Markers Linked to Blooming Time in Almond

In this study flowering time and other important morphologic traits were evaluated during two years in F1 almond progenies of seventy two seedlings from cross between the intermediate flowering Italian cultivar ‘Tuono’ and the extra-late blooming Iranian cultivar ‘Shahrood-12’. A modified-bulk segregant analysis in combination with the application of the 140 RAPD primers, 87 nuclear SSR markers spanning the whole almond genome and 5 chloroplast SSR markers, were used to identify molecular markers linked to flowering time. Results showed a quantitative inheritance of this trait in the studied progenies. The seedlings showed a wide range of flowering dates between both progenitors although some of these descendants were earlier in flowering than the early progenitor ‘Tuono’. Results showed that among RAPD markers evaluated, BA-17600,1000, BC-05320, BC-06800, BC-141750, BC-17600, BC-20250, OPC-05850 and OPC-09700,1100 markers were linked to late blooming time. In addition, markers BA-04720, BB-10630,BC-092000, BD-12510andOPC-12350 were linked to early blooming time. Two microsatellite loci (CPPCT008 and EPPCU2584) were also found to be tightly linked to flowering time. After construction the genetic map of population, QTL analysis was performed for blooming time. QTL analysis showed that OPC-09700,1100 and BA-17600,1000, markers were respectively located in 2 and 4 cM distance from one of the late flowering time loci. Also the BA-04720marker was located in 3 cM distances from one of the loci controlling early flowering time. These results are applicable in almond breeding programs for markers assisted strategy. The application of these results to other Prunus species has been also discussed.