Genetics of Seed Yield and Its Components in Cowpea [Vigna unguiculata (L.) Walp.]

An investigation to study the genetics of seed related attributes in cowpea [Vigna unguiculata (L.) Walp.]” was undertaken atSardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar. Three crosses (GC 2 x PGCP 5, GC 2 x PGCP 13 and GC 516 x PGCP 1) along with its parental seed, F₂, BC₁ and BC₂ made the complete set of six generations (P₁, P₂, F₁, F₂, BC₁ and BC₂) for genetic analysis. The experiment was laid out in a Compact Family Block Design with threereplications during kharif 2011. A single replication comprised of one row of parents and F₁, two rows of the backcrosses generations, BC₁ and BC₂ and four rows of the F₂. The characters viz., days to flowering, days to maturity, number of pods per plant, number of seeds per pod, seed yield per plant, biological yield per plant, harvest index and 100-seed weight weresubjected to generation mean analysis to assess the gene effects controlling these traits. The analysis of variance revealed significant differences among generations in most of the characters studied in all the three crosses, except days to flowering in crosses I and II, indicating considerable variability in the experimental material. The scaling tests (A, B, C and D)indicated appreciable amount of epistasis present in different characters of three crosses under the study, indicated the failure of a simple genetic model to explain the genetic system controlling the studied traits in the three crosses studied. Generation mean analysis revealed that different gene effects were responsible for the inheritance of the same trait indifferent crosses and for different traits in the same cross, specific handling of individual cross in segregating generations would be advantageous for improvement of these traits. In the present investigation, non-allelic interaction played pertinent role in determination of various characters in cowpea. Thus, breeding methods involving high volume crossing likebiparental, recurrent and diallel selective mating design that take care of both additive and non-additive gene action seemed more promising for the improvement of various characters studied.