Selection of Cowpea Elite Lines for Iron and Zinc Biofortification

Abstract

Background: Cowpea is a very popular crop in Brazil, rich in nutrients that can be used as food to feed the population, avoiding deficiencies caused by the lack of minerals such as iron and zinc. Objective: To select elite cowpea lines for biofortification of iron and zinc and determine the physical and chemical characteristics of the lines. We analyzed: 33 cowpea genotypes, being 31 elite genotypes and two biofortified cultivars (control). Method: The 10 best lines with iron and zinc contents were selected and, together with the controls, were analyzed for chemical composition (moisture, ash, lipids, proteins and carbohydrates), total energy value and cooking time. Results: The iron and zinc contents in semi-prostrate genotypes were higher than those in semi-erect genotypes, all the semi-prostrate lines presented a high iron content, and 19.25% presented a high zinc content. The genotypes of the semi-erect lines exhibited more significant genetic variability for iron content, whereas those of the semi-prostrate genotypes showed more significant genetic variation for zinc content, both exhibited a high genetic component in phenotypic expression. Improving the genotypes for increased protein content led to reductions in lipid and carbohydrate contents, as well as the total energy value, whereas increasing the carbohydrate content increased both the total energy value and the zinc content. The MNC04-792F-146 lines presented alleles that favored an increase in carbohydrate content and total energy, while the MNC04-769F-26, MNC04-769F-31, and MNC04-774F-90 lines were shown to be good sources of genes for increasing protein content, decreasing lipid content, and rapid cooking. Conclusion: The MNC04-762F-9, MNC04-792F-146, and MNC04-769F-55 lines exhibited the greatest potential to be released as iron and zinc biofortified cultivars.