Flowering in cultivars of sesame (Sesamum indicum) Differing in photoperiodic sensitivity

Studies of flowering in sesame (Sesamum indicum L.) under different photoperiods revealed that cultivars Glauca, Venezuela-52 and Oro were short day strains while a fourth cultivar, Aceitera, proved to be day length neutral. Sensitivity to varying photoperiods, then, does not seem to be a universal characteristic of all sesame cultivars. Also, no correlation was found between photoperiodic class and latitude of origin in the cultivars studied. Inheritance studies involved crosses between the day neutral cultivar and two of the short day cultivars. In all cases, the F₂ populations demonstrated continuous variation. Most of the F₂ variability was of genetic origin and heritability values ranged from 86 to 96%. Additionally, transgressive segregation was observed for both early and late flowering. It is proposed that a minimum of three loci are involved in the inheritance of photoperiodic response in the sesame cultivars studied.