Dreb1 genes in wheat (Triticum aestivum L.): development of functional markers and gene mapping based on SNPs

The Dreb genes are involved in abiotic stress tolerances, such as drought, salinity, low temperature and ABA. The purpose of the present research was to establish protocols for the development of genome-specific and allele specific markers in common wheat (Triticum aestivum L.) using the Dreb1 genes as an example. Based on the available sequences of Dreb1 genes in common wheat and related species, five primer pairs were designed using Primer Premier 5.0. Two primers, P25F/PR and P21F/P21R, amplified 596- and 1113-bp fragments, respectively, from the A genome, P18F/P18R amplified a 717-bp fragment from the B genome, and primers P22F/PR and P20F/P20R amplified 596- and 1193-bp fragments, respectively, from the D genome. Using these genome-specific primers and the Chinese Spring using nulli-tetrasomic lines, the Dreb1 genes were located on chromosomes 3A, 3B and 3D. Two SNPs (S646 and S770) in Dreb-B1 distinguished the Opata 85 and W7984 parents of the ITMI mapping population, but there was no polymorphism between the orthologous Dreb-A1 and Dreb-D1 sequences. By assaying the genotypes of 115 RILs with the allele-specific primer P40 based on SNP S770, Dreb-B1 was mapped between markers Xmwg818 and Xfbb117 on chromosome 3BL. This genetic mapping of Dreb-B1 on chromosome 3B may be helpful in wheat breeding programs aimed at improving drought tolerance.