Direct Organogenesis in Dioscorea Species

Protocol was developed for direct adventitious shoot regeneration from leaf and petiole explants of six species of Dioscorea in MS medium augmented with varying concentrations and combinations of cytokinins and auxins. Leaf explants responded well in cultures of Dioscorea pentaphylla, D. hamiltonii. D. wightii and D. intermedia followed by petiole in D. bulbifera and D. hispida. Cytokinins are effective in promoting direct shoot initiation. Amongst different cytokinins, BA was effective in producing maximum bud sprouting from leaf explants of D. pentaphylla. where 3 bulbils and 8 shoot buds got regenerated in 2 mgll while D. wightii in BA at 4 mg/l induced 3 shoots. Kinetin (2 mg/l) in the medium also induced 16 shoots from leaf explants of D. hamiltonii. Synergistic effect of BA (3 mg/l), Kin (1 mg/l) and NAA (1 mg/l) initiated the development of 12 shoots in D. pentaphylla from leaf explants.