Rapid clonal propagation of Dioscorea zingiberensis

Abstract

A protocol was developed for rapid in vitro propagation of Dioscorea zingiberensis Wright using stems as explants. MS medium with the macroelements at half strength and supplemented with 20.0 g l⁻¹ sucrose and 8.0 g l⁻¹ agar was used as basal medium. Lateral buds on nodal cuttings grew into shoots within 20 days after culture on basal medium supplemented with 4.4 μM 6-benzylaminopurine (BAP) and 1.1 μM α-naphthalene acetic acid (NAA). The shoots were cut into segments and cultured on medium with 8.9 μM BA and 5.4 μM NAA for 30 days for callus formation. The callus was cut into pieces and cultured on medium containing 22.2 μM BAP and 1.1 μM NAA, on which 87.5% of the callus pieces regenerated multiple shoots within 50 days. The shoots were rooted on medium containing 4.9 μM indole-3-butyric acid (IBA) for 20 days. Adventitious buds and shoots could be repeatedly formed after the calli were cut into pieces and cultured on the medium containing 8.9 μM BAP plus 1.1 μM NAA. More than 85% of the regenerated plantlets survived and grew vigorously 1 month after they were transplanted in vermiculite and each plant formed 2–4 microtubers 3 months of transplanting.