Genetic Study of Earliness in Cowpea ( Vigna unguiculata L. Walp) Under Screen House Condition

摘要

Genetic effects for earliness were determined from a cowpea cross under screen house condition using generation mean analysis from six populations (P1, P2, F1, F2, BC1 and BC2). The result from this study suggests that earliness is under polygenic control. Generation mean analysis did not fit an Additive dominance model. The Additive and dominance effects were low with the dominance component not significantly different from zero. The Additive x Additive (I) and Dominance (h) effects were negative with diminishing effects suggesting an enhancing effect on earliness while the Additive x Dominance (j) effect was high and positive suggesting an enhancing effect for late maturity. The narrow sense heritability was high 90.87%. Genetic advance assuming 10% selection intensity of the earliest or latest flowering plants was selected for further propagation is expected to be ±17 days. The Additive (d), Additive x Additive (I), Additive x Dominance (j) and Dominance x dominance (l) interaction were the most important gene actions conditioning earliness.