Genotype by Environment Interaction, Combining ability, Heterosis and Heritability for fruit yield characters in hybrids from 8 x 8 diallel cross of West African Okra ( Abelmoschus caillei (A. Chev) Stevels)

Combining ability, heritability and heterosis was investigated among population developed from 8 x 8 diallel crossing pattern in 2012 and 2013 cropping season Mubi and Makurdi. Investigations were undertaken using a randomized complete block design. Selection by stakeholders considering pod gelatinization and overall appealing of fresh and dried okra pods and other sensory characters was carried out in Mubi. Significant differences (P < 0.05) were found among the entries for most characters during the 2012 and 2013. Earliness and plant height showed high discriminatory ability among the population. The pooled analysis of variance over years and locations for agronomic characters returned significant differences across locations, years and genotypes by location interaction for earliness, plant height, yield and yield component characters. This is consistent with high variability among the parents and crosses in their responses to different soil and climatic changes in both years and locations. GCA variance for agronomic characters except for pod diameter, seed weight and fruit yield reflects additive and additive x additive type of gene action. Therefore the best hybrid across locations and years may be produced by crossing parents with the highest GCA effect for desirable character. Early generation selection among the segregating population may rapidly evolve desirable population upon which new crop varieties can be developed after periods of selfing. High broad sense heritability for earliness, plant height, and pod length, pod width and seed weight was consistent with high additive gene effects. While low heritability estimates was related to the presence of dominance gene for some characters. About 40% improvement in pod number was recorded in the cross P2 × P8 in RMPV and RHPV.