Review: Breeding wheat for enhanced micronutrients

Low concentrations or deficiencies of bioavailable iron (Fe), zinc (Zn) and other essential micronutrients in human food afflict a large proportion of the world's population. Plant biofortification, to improve the mineral concentrations in the edible portions of crop plants by conventional breeding or modern transgenic approaches, is regarded as the most economical and sustainable strategy. Many researchers have demonstrated that there are significant differences in grain mineral element concentrations among wheat (Triticum aestivum L.) and its relatives. Compared with cultivated wheat, wild wheats are potential genetic resources for enhancing micronutrient in wheat grain. An ancestral wild tetraploid wheat (T. turgidum ssp. dicoccoides) carrying the allele Gpc-Bl, which is associated with increased Fe, Zn, and protein concentrations in grain, was cloned using a positional cloning strategy. Combining conventional breeding with modern genetic engineering approaches, such as introgression of genes from wild relatives into wheat, synthetic hexaploid wheat, quantitative trait locus (QTL) analysis, and even gene cloning and genetic transformation, are important for developing wheat cultivars higher in micronutrients.