Micropropagation of Harpagophytum procumbens

An efficient protocol for micropropagation of Harpagophytum procumbens DC., an endangered African medicinal plant, was developed. Maximum shoot multiplication without callus was obtained from nodal explants cultured on Murashige and Skoog (MS) basal salts plus Gamborg’s (B₅) vitamins supplemented with 0.1 mg dm⁻³ indole-3-acetic acid and 5.0 mg dm⁻³ kinetin. The shoots were subsequently subcultured every 3 weeks on the same medium. Detached axillary shoots were transferred to MS basal salts plus B₅ vitamins supplemented with various concentrations of α-naphthalene-acetic acid or indole-3-butyric acid (IBA), ranging from 0.5 to 2.5 mg dm⁻³ and 100 % rooting and optimal subsequent acclimatization was achieved on 1.0 mg dm⁻³ IBA. After 4 weeks of culture, the rooted shoots (>5 cm) were planted in pots containing peat, vermiculite and bark (2:1:1), covered with plastic domes and maintained at 25 °C for 2 weeks before being transferred to a glasshouse. Plant survival was about 40 %.