Estimation of Genetic Parameters of Yield Traits in Crosses of Cowpea

Abstract

The experiment was conducted in understanding and describing the nature and extent of genotypic and phenotypic variation, heritability, expected genetic advance, as well as gene effects between yield and yield components of cowpea. The experiments were conducted in the Department of Agricultural Technology, Federal College of Forestry, Jericho, Ibadan, Nigeria. Five generations (P₁, P₂, F₁, F₂ and F₃) of three crosses from three cowpea lines (TVu1xTVu14019, TVu1xTVu3629 and TVu3629xTVu14019).

In days to flowering, there was no epistatic effect in the cross TVu3629 x TVu14019. All the crosses exhibited high broad sense heritability and moderate genetic advance as percentage of mean for pod length, number of seeds per pod and 100 seed weight while cross TVu1 x TVu14019 and TVu1 x TVu3629 also in seed yield per plant. There was significant complementary and duplicate epistatic gene effect in days to flowering, pod length, number of seeds per pod in the cross involving TVu1 with TVu3629 and TVu14019. There was significant epistasis gene effect in the cross of TVu3629 x TVu14019 in pod length, number of seeds per pod and 100 seed weight.

High magnitude of broad sense heritability along with moderate to high genetic advance as percentage of mean recorded for days to flowering, pod length, number of seeds per pod, 100 seed weight and seed yield per plant indicated that these characters can be improved through selection in advanced generations. Since different gene effects were responsible for the inheritance of the same character in different crosses and for the different characters in the same cross specific handling of individual crosses for different characters would be advantageous for the improvement of these characters. The characters controlled by both additive and non-additive gene effects can be successfully improved by utilizing hybrid vigour or biparental mating method of breeding.