Effects of Combination of Different Levels of Auxin (NAA) and Cytokinin (BAP) on in vitro Propagation of Dioscorea rotundata L. (White Yam)

Studies were carried out with the aim of evaluating in vitro the effects of growth regulators-auxin (NAA) and cytokinin (BAP) combined at different levels on Dioscorea rotundata regeneration potentials on modified Murashige and Skoog media. Concentrations of 0, 0.25, 0.5, 0.75, 1.00 mg L-1 and 0, 0.1, 0.2, 0.3 and 0.4 mg L-1 of NAA and BAP, respectively were used to subculture healthy white yam plantlets. The plant height, number of leaves, nodes, vines, roots and fresh weights were evaluated. Results obtained when analyzed at 5% level of significance showed that the concentration of both hormones (auxin and cytokinin) had significant effects on plant regeneration. BAP (0.2 mg L-1) in combination with NAA (0.5 mg L-1) showed more increase in almost all the parameters measured when compared to other concentrations combined.