QTL Mapping of Low Cadmium Uptake in Durum Wheat (Triticum turgidum L. var. durum).

Cadmium (Cd) is a biotoxic heavy metal present in low concentrations (mg/kg per range) in the agricultural soils worldwide. High cadmium (Cd) level in durum wheat has become a serious problem that might have an impact on the pasta industry and the international export market due to the large amount of Cd accumulated in their products. The purpose of this research was to identify quantitative trait loci (QTL) for seed Cd concentration in durum wheat. Lines that exhibit low Cd uptake will be used in future research in durum wheat breeding programs as a source for low Cd uptake cultivars development. A population of 165 F_4:7 recombinant inbred lines (RILs) derived from a cross between the low Cd uptake cultivar Haurani and the high Cd uptake cultivar Grenora was used for QTL mapping. Cadmium phenotypic data from the RILs will be used to develop a linkage map of single nucleotide polymorphisms (SNP) markers that associate genes to their location on chromosomes based on the frequency of recombination events occur using the software MapDisto version 2.5. SNP marker data with a GenTrain score of ≥ 0.25 will be used for generating the map.  A minimum LOD score of 3.0 for two-point analysis will be used to determine linkage relationship among markers and for multipoint analysis to establish the best loci order in the chromosome. The data obtained from the linkage map will be imported for QTL analysis by using the software QTL Cartographer v. 2.5 for QTL identification. QTL detection will be performed by using both simple interval mapping (SIM) and composite interval mapping (CIM) functions separately for combined analysis if there is no G x E interaction. We expect to identify a novel markers linked to the QTL that governs Cd uptake to be suitable markers for selecting genotypes with low seed Cd concentration in Durum wheat.