QTL discovery for grain iron and zinc content in wheat: Pathway to biofortification

Abstract

A deficiency of micronutrients causes hidden hunger, ultimately leading to malnutrition. Biofortification through marker-assisted breeding can be the most effective way to overcome this problem. Therefore, the identification of genomic regions (QTLs) for grain micronutrients like Fe and Zn can articulate the researchers for quicker and more accurate development of micronutrient-rich wheat varieties through marker-assisted breeding. In this study, QTLs were identified for grain Fe and Zn concentration of 214 mapping lines in F2:3 population derived from a biofortified variety, HD 3298 and M-160, a mutant line deficient for Fe and Zn developed from DPW 62150. Person correlation coefficient analysis between GFeC and GZnC content revealed that there is a significant positive correlation between the micronutrients (r = 0.95). Again, 700 SSR markers were used for genotyping of which 547 were monomorphic, while 153 were polymorphic in both the parents with a polymorphic rate of 21.11%. Linkage map construction discovered that a total of 17 QTLs were dispersed on nine chromosomes out of which five QTLs correspond to GFeC with an average LOD value of 14.73% which mapped on chromosomes, 1A and 7A. Similarly, 12 QTLs correspond to the trait GZnC with an average LOD of 14.03% and are mapped on chromosomes, 2A, 4A, 5B, 5D, 6A, 7B and 7D. The mean GFeC content of mapping lines was 34.46 mg/kg and for GZnC was 22.59 mg/kg with SE of 0.65 and 0.40, respectively. These identified QTLs can be triggered as valuable tools for advanced molecular breeding practices.