Biofortified Wheat for Mitigating Malnutrition

Zinc, iron, and provitamin A are the critical micronutrients required for structural and functional integrity of biological system. Their deficiency affects billions of people worldwide, by hampering growth and development and destroying the immune systems. Micronutrient-dense wheat (Triticum aestivum L.) varieties can be developed by using the existing genetic variability in the germplasm. Even with new screening tools such as gene discovery, marker-assisted selection, and precision phenotyping, selection of high-Zn genotypes would appear an easy task. Wide genetic variation available in primitive and wild relatives, landraces, and synthetic hexaploids is now being intensively exploited under HarvestPlus program to identify quantitative trait loci (QTLs) for enhancing concentration of Zn and its bioavailability in wheat grain. Further regulation of gene expression in identified QTLs in response to biotic and abiotic stresses is also analyzed. The ultimate goal of this program is to improve nutritional status of wheat cultivars. However, enhancement of Zn uptake through utilization of genetic variation would be possible only when the soil environment (i.e., mineral composition) has sufficient zinc pool for absorption. The varieties like BHU 1, BHU 17, and BHU 19 from India and NR 419, NR 420, and NR 421 from Pakistan show 4–10 ppm increase in grain zinc. Agronomic biofortification strategies through application of Zn-containing fertilizer provide an immediate and effective option to increase grain Zn concentration and productivity in wheat, particularly in areas of severe nutrient-deficient soil. Zn fertilizer can be used along with the pesticide used to control aphids or yellow rust in wheat. Fertilizer application strategies must be practical and economically feasible. However, in developing countries where resource-poor farmers cannot afford fertilizer, breeding for mineral density may remain the sole agricultural intervention to improve the nutritional content of staple crops.