Studies on heterosis in Abelmoschus esculentus (L.) Moench and A. callei (A. Chev) stevels cultivars during shorter day photoperiods in south eastern Nigeria.
Better parent heterosis was studied in direct and reciprocal crosses using 9 early and late okra cultivars which belonged to the Early-early, Early-late, Late-early and Late-late okra flowering types. The ANOVA for length of pod, circumference of pod, number of locules per pod, number of seeds per pod, Number of pods per plant, weight of 1000 seeds, density of seeds, weight of pods per plant, days to flower opening, plant height and circumference of stem at 10 cm above soil level, showed almost very highly significant differences-an indication that the cultivars are genetically diverse. Very highly significant, narrow and intermediate, heterosis was recorded for most of the direct and reciprocal crosses, showing that selections could be made from the hybrids to meet desired local okra qualities. A cross between an Early-late and Late-early parents, using early okra as the maternal parent, gave rise to a stable viable bridge hybrid which outperformed the better parent in many respects thereby overcoming the hitherto strong barrier to gene flow in interspecific hybridization studies involving the two okra types and also indicating the existence of maternal effects. Consequently with this development, the window has been opened for possible accelerated transfer of several desirable genes from late okra types to many promising but vulnerable early okra types. This could result to minimizing the further erosion of such early okra germplasm still in the custody of the local farmers.
Genetics and Plant Breeding Unit, Department of Botany, Faculty of Biological Sciences, University of Nigeria, Nsukka, Nigeria.
Obi Sergius
OS
Udengwu
D028483:Abelmoschus / Q000235:genetics* / Q000502:physiology; D003433:Crosses, Genetic; D003624:Darkness; D035264:Flowers / Q000235:genetics / Q000502:physiology; D006823:Hybrid Vigor; D008027:Light; D009549:Nigeria; D017440:Photoperiod; D012639:Seeds / Q000235:genetics / Q000502:physiology