Hybrid vigour and gene action for two quantitative traits of castor plant (<i>Ricinus communis</i> L.)

Abstract

Five homozygous lines of castor plant, namely RS1-Om, RN1-Om, RTl-2m, RSl- Owm, and RNl- Omb, were crossed to raise F1, F2, BC1, and BC2 generations. The hybrids were tested for hybrid vigour for two metric traits, viz; number of pods per plant and seed yield per plant. Highly significant hybrid vigour was detected for both traits in all the crosses. The contributions of additive and non-additive gene effects to both traits were also investigated. Additive gene effects were more relevant in the inheritance of number of pods per plant. The effects of the digenic interactions, coupled with the highly significant additive gene effects on number of pods per plant in most of the crosses, tend to suggest that improvement of the character can be enhanced by the use of breeding methods such as the reciprocal recurrent selection that would encourage the concentration of genes involved in the inheritance of the trait. The contributions of dominance gene effects to the total genetic variance were positive and highly significant in both pod and seed yield per plant in all the hybrids. This would tend to favour hybridization and the use of first generation hybrids as an effective means of improving both traits in castor plant. Thus, reciprocal recurrent selection and the use of hybrid programmes are the breeding strategies suggested for the improvement of pod and seed yield in castor plant.


Ghana Jnl agric. Sci. Vol.31(1) 1998: 81-86