Published online by Cambridge University Press: 27 March 2009
The tubers of Dioscorea composita Hemsl. contain a high level of diosgenin, and hence there is economic interest in this plant. Levels of diosgenin vary greatly in different clones of the species. Vegetative propagation was studied with a view to obtaining plants with high levels of diosgenin. In this study cuttings from 1-year-old vegetative plants were used for propagation. The cuttings were treated with a single application of indole-3-butyric acid (IBA) and several applications of 6 benzyladenine (6-BA). Rooting was never observed in untreated cuttings. Cuttings treated with IBA produced callus and roots. Early application of 6-BA delayed senescence but inhibited callus and root formation. New plants were obtained with one application of IBA followed by applications of 6-BA at 48 h intervals initiated 2 weeks after IBA application. In some experiments, all cuttings treated this way produced new plants.