In vitro micropropagation, differentiation of aerial bulbils and tubers and diosgenin content in Dioscorea bulbifera.

Dioscorea bulbifera could be micropropagated through nodal segments and bulbils. The best medium for regeneration and bulbil differentiation was MS + 0.5 microM IAA (indole-3-acetic acid) + 20.0 microM Kn (kinetin) + 500 mg/L CH (casein hydrolysate) + activated charcoal (20 %). Diosgenin content was maximum in regenerants grown on MS + 5.0 microM IAA + 20.0 microM Kn + 500 mg/L CH. T.s of bulbils could also be used for direct plantlet differentiation as well as bulbil differentiation on MS + 10.0 microM IAA + 20.0 microM Kn + (in mg/L) 30 each of Asp (asparagine) + Arg (arginine) + Gln (glutamine) + 10 Ad (adenine) + 500 CH + 10 Cyst hyd (cysteine hydrochloride). Diosgenin yield in plantlets reached a maximum after 20 weeks. The results indicate that micropropagation, bulbil formation and tuberisation can be achieved in vitro in D. bulbifera, hitherto a less exploited plant, and can further be used for obtaining enhanced levels of diosgenin.