Characterization of biofortified harvestplus wheat genotypes for root uptake, shoot translocation, foliar absorption, re-mobilization and seed deposition of Zn

Chronic micronutrient deficiencies, particularly Zn and Fe, also known as “hidden hunger”, is a major public health problem, affecting over two billion people worldwide particularly women and children in developing countries. Genetic and/or agronomic biofortification of cereal crops like wheat are considered as a reasonable solution to prevalent Zn deficiency problem in the human population of developing world. As an international group, HarvestPlus program along with collaboration of public and private partners has taken initiatives to develop the biofortified high Zn wheat cultivars along with desired agronomic traits. Current study aimed to evaluate the performance of the high Zn biofortified wheat genotypes developed through long-term breeding activities under the HarvestPlus program in Pakistan and India. Ten advanced breeding lines and two mega varieties as check were tested under four fertilizer treatments i) Deficient Soil Zn (or control) ii) Foliar Zn application iii) Soil Zn application iv) both soil and foliar Zn. The results indicate that biofortified lines have higher capacity to absorb and accumulate Zn in grain from soil and foliar Zn fertilizer as compared to check cultivars. A positive correlation was observed in grain yield and grain Zn concentration of biofortified lines. As an average of all biofortified genotypes, 18 % increase in yield and 3.5 folds increase in grain Zn concentration were recorded with the application of both soil and foliar fertilizers. Highest grain yield and grain Zn concentration was observed in an Indian biofortified genotype with both Soil + Foliar Zn application. In Zn-deficient calcareous soils of south Asian countries like Pakistan and India, integrated strategy of growing genetically biofortified wheat cultivars with an added application of Zn in soil and foliar form is the best strategy to improve yield and grain Zn accumulation, and hence to overcome the malnutrition problem.