Micronutrients deficiency is a major contributor to poor health in developing countries. It can be alleviated by biofortification or enrichment of staple crops with micronutrients. Sweetpotato is a major staple crop in numerous tropical countries and is naturally biofortified. In spite of extensive promotion of orange-fleshed sweetpotato varieties (OFSPs), they are poorly utilized as staple food in most parts of West Africa because of their low dry matter and high sugar content. Beta-carotene is positively correlated with iron and zinc content in sweetpotato. Development of sweetpotato cultivars with end-user preferred traits and higher content of beta-carotene, iron and zinc will alleviate their deficiencies. Knowledge on the genetic control of these traits is critical for their improvement in sweetpotato. This study used diallel mating design to estimate general combining ability (GCA) and specific combining ability (SCA) of storage root beta-carotene, iron and zinc content to determine the genetic control of these traits for sweetpotato breeding. A general model for estimating genetic effect, Gardner and Eberhart analysis II (GEAN II), was used for data analysis. Genetic variability for the traits indicated that they were mostly controlled by additive gene effect. Significant heterosis was found indicating that levels of these micronutrients can be improved in sweetpotato through breeding. 

 

Micronutrients are vitamins and minerals required in small amounts that are essential to human health, development, and growth. They include folic acid, iodine, iron, vitamin A and zinc. They play a central role in metabolism and maintenance of tissue function. Micronutrient deficiencies are a chronic deprivation of these nutrients and constitute a huge public health problem, adversely affecting a third of the world’s population. Nearly 100 million preschool children in the world suffer from vitamin A deficiency. Thousands of death of children under five years worldwide are attributed to vitamin A deficiency, while anemia, which is caused by inadequate intake of iron, affects 1.6 billion people around the globe. Severe and extensive deficiencies also prevail for zinc. Micronutrients deficiency can be alleviated in several ways including dietary diversification, fortification, supplementation and biofortification. Among these different ways, biofortification which is the genetic enhancement of edible parts of plants with micronutrient concentration is the safest and the most cost effective. Biofortification can be achieved by breeding for farmer and consumer preferred cultivars that have adequate amount of micronutrients.