QTL Analysis for Fe and Zn Concentrations in Rice Grains Using a Doubled Haploid Population Derived from a Cross Between Rice (Oryza sativa) Cultivar 93-11 and Milyang 352

Biofortification is a cost-effective method for increasing the availability of micronutrients. Rice breeding for high levels of micronutrients is one of the best approaches to solve the problem of malnutrition. In this study, we developed a doubled haploid (DH) population derived from a cross between the rice cultivars 93-11 and Milyang 352 and evaluated QTLs for grain micronutrients and grain shape. Two co-localized QTLs, qFe3-1 and qZn3-1, were identified in the interval between ah03002520 and cmb0336.5 on chromosome 3, which explained 17.6% and 10.5% of the phenotypic variation, respectively. Correlation analysis between agronomic and micronutrient traits showed positive correlations between grain Fe and Zn contents but a negative correlation between grain Fe content and length-to-width ratio. This indicated the possibility of simultaneously increasing both Fe and Zn content in rice grains for improving the micronutrient profile of rice. We selected some promising lines by recombinant selection using linked markers on chromosome 3. The co-localized QTLs qFe3-1 and qZn3-1 might be useful for the improvement of biofortified rice breeding by markerassisted selection and gene pyramiding.