Mapping QTLs Associated with Grain Iron and Zinc in Sorghum (Sorghum bicolor L. Moench)

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 concentration and understanding the genetic basis of high Fe and Zn concentration is prerequisites for manipulation of these micronutrients. In this study we analysed iron and zinc concentration in recombinant inbreed line (RIL) population of 340 lines derived from cross between 296B, a grain mold susceptible with low grain iron/zinc concentration and PVK801, a grain mold resistance with high grain iron/zinc concentration. The population was planted across three locations for two years each; grains of the RIL population were evaluated for Fe and Zn concentration using inductively coupled plasma atomic emission spectroscopy (ICP-OES). The grain Fe and Zn concentrations in the RIL population ranged from 29.06 to 48.28 and 16.57 to 41.86 mg/kg, respectively. While we are further analyzing the phenotypic data for the genetic variation and genotype-by-environment interaction, we have already generated circa 30 SSRs and few hundred Diversity Array (DArT) SNPs data. These will be used for genetic dissection of the grain iron and zinc content for mapping QTLs. This will provide further opportunities to elucidate the underlying physiological mechanism involved in grain iron/zinc accumulation in sorghum.