Genetic Analysis of Total Seed Protein Content in Two Cowpea Crosses

Genetic parameters, heritability, and minimum number of genes for total seed protein content were estimated in tropical semiarid‐adapted cowpea [Vigna unguiculata (L.) Walp.] germplasm aiming to provide the basis for the development of cultivars with higher nutritional value. Generation mean and variance analyses were conducted with the parental lines, F1, F2, and backcross populations derived from two contrasting crosses ‘IT97K‐1042‐3’ (31.15% total seed protein content) × ‘BRS Tapaihum’ (24.35%) and IT97K‐1042‐3 × ‘Canapu’ (22%). Narrow‐sense heritabilities were moderate (47.7%) in the cross IT97K‐1042‐3 × BRS Tapaihum and high (87.6%) in the cross IT97K‐1042‐3 × Canapu. The analyses indicated (in both crosses) the importance of additive gene effects and the parental mean for total seed protein. The minimum gene number, estimated by different methods, ranged from three to seven in the IT97K‐1042‐3 × Canapu cross and three to less than 25 in the IT97K‐1042‐3 × BRS Tapaihum cross. Transgressive segregation was observed in the F2 population from the cross IT97K‐1042‐3 × Canapu, with individual plants displaying up to 34.1% seed protein content. The results suggest that, although under polygenic control, the seed protein content in cowpea can be improved via standard breeding methods largely used in self‐pollinated crops.