Breeding and agronomic approaches for the biofortification of zinc in wheat (Triticum aestivum L.) to combat zinc deficiency in millions of a population: a Bangladesh perspective

The World Health Organization (WHO) has estimated that around 2 billion people across the globe are suffering from hidden hunger, where 815 million are under malnutrition. The major essential elements for humans are Fe, Zn, I, Se, Ca, F, and also vitamins. Among them, Zn is considered in the fifth place leading to causes of several deficiency diseases. At least one-third of the population in the world is facing Zn deficiency including around 450,000 children under the age of five. Vitamin A, Fe, and Zn deficiencies can be overcome through the biofortification of staple foodstuffs. This review emphasizes various breeding and agronomic approaches for the biofortification of Zn in wheat grains, which is an encouraging and cost-effective method to enhance the Zn contents of cereal grains. Recently, the Bangladesh Wheat and Maize Research Institute (BWMRI), with technical support from CIMMYT, Mexico, released a promising new Zn-biofortified wheat cultivar, 'BARI Gom 33', a result from a conventional breeding program. It has 32 and 50-55 mg kg(-1) Zn without and with soil application of ZnSO4, respectively. This cultivar could be a savior for a million people in South Asia, including Bangladesh.