Further studies on pyramiding of alien genes for high grain Fe and Zn in bread wheat

Wheat serves as the primary source of staple food for the global human population, thus also making it a significant portion of the calorie intake in our daily vegetarian diets. However, in most of the improved wheat cultivars used for food, the grain is deficient in iron (Fe) and zinc (Zn). Therefore, biofortification involving improvement of grain Fe and Zn has become an important area in the current wheat breeding programmes. For this purpose, efforts have been made to develop alien substitution lines and utilize them for transfer of desirable alien genes to improved wheat cultivars. In the present study, two such genotypes in the background of improved cultivar PBW343LrYr were utilized for pyramiding of the following six desirable genes for enrichment of grain Fe and Zn: IRT2, MTP3, IREG, FRO7, YSL15 and NAS2. A forward breeding strategy, involving crossing of the two genotypes followed by inbreeding was used. Marker-assisted selection (MAS) of the genes of interest associated with grain Fe/Zn and plant type was used following selfing of F₁ hybrids. The grains of F₆ lines that were derived in this programmes were rich in both Fe and Zn contents in the grain. Among the six best derived lines, the values of improved contents of grain Fe ranged from 47.3 to 60.4 ppm and that of Zn ranged from 39.35 to 47.85 ppm. There was no yield penalty in these improved lines, such that the yield was either equal or better than the checks used in field trials.

The online version contains supplementary material available at 10.1007/s11032-025-01566-0.