Nutritional composition of immature pods in selected Cowpea [Vigna unguiculata (L.) Walp.] genotypes in South Africa

Information on genetic variability among genotypes is useful in crop improvement programmes. The study was carried out to determine the variability of nutritional composition in the immature pods of selected cowpea genotypes for use in breeding for nutritional qualities. A total of 11 mineral elements (K+, Ca2+, P3-, Mg2+, Na+, Fe2+, Mn2+, B3+, Al3+, Zn2+, Cu+) and total protein content were determined for the green immature pods of 22 cowpea genotypes collected from Nigeria and South Africa. The univariate analysis revealed significant differences among the genotypes for the traits evaluated. Genotype ITOOK-1060 has the highest value of Mg (4262.00 mg kg-1), Na (329.33 mg kg-1), B (14.31 mg kg-1), Al (78.61 mg kg-1), Zn (56.25 mg kg-1) and Cu (9.00 mg kg-1). TVU-14196 has the highest values for Fe (97.78 mg kg-1) and Mn (44.75 mg kg-1) while 98K-5301 has the highest values for K (24078.00 mg kg-1), Ca (8677.70 mg kg-1), P (5375.30 mg kg-1) and protein (28.54%). The multivariate analysis showed wide genetic variability among the genotypes which could be exploited in selecting suitable parents when breeding for nutritional qualities. High heritability estimates were also observed in most of the traits evaluated indicating potential genetic gain when breeding for these traits. The present study revealed the genetic potential of the genotypes studied and their importance for use in the breeding programme aimed towards combating nutritional deficiencies and food insecurity in South Africa.