Mapping of quantitative trait Loci for grain iron and zinc concentration in diploid A genome wheat

Micronutrients, especially iron (Fe) and zinc (Zn), are deficient in the diets of people in underdeveloped countries. Biofortification of food crops is the best approach for alleviating the micronutrient deficiencies. Identification of germplasm with high grain Fe and Zn and understanding the genetic basis of their accumulation are the prerequisites for manipulation of these micronutrients. Some wild relatives of wheat were found to have higher grain Fe and Zn concentrations compared with the cultivated bread wheat germplasm. One accession of Triticum boeoticum (pau5088) that had relatively higher grain Fe and Zn was crossed with Triticum monococcum (pau14087), and a recombinant inbred line (RIL) population generated from this cross was grown at 2 locations over 2 years. The grains of the RIL population were evaluated for Fe and Zn concentration using atomic absorption spectrophotometer. The grain Fe and Zn concentrations in the RIL population ranged from 17.8 to 69.7 and 19.9 to 64.2 mg/kg, respectively. A linkage map available for the population was used for mapping quantitative trait loci (QTL) for grain Fe and Zn accumulation. The QTL analysis led to identification of 2 QTL for grain Fe on chromosomes 2A and 7A and 1 QTL for grain Zn on chromosome 7A. The grain Fe QTL were mapped in marker interval Xwmc382-Xbarc124 and Xgwm473-Xbarc29, respectively, each explaining 12.6% and 11.7% of the total phenotypic variation and were designated as QFe.pau-2A and QFe.pau-7A. The QTL for grain Zn, which mapped in marker interval Xcfd31-Xcfa2049, was designated as QZn.pau-7A and explained 18.8% of the total phenotypic variation.