In vitro propagation of a medicinal plant: Tripterygium wilfordii Hook f.

In this study a reliable protocol was developed for the establishment of commercial in vitro cultures of Tripterygium wilfordii Hook f. Juvenile shoots from one-year-old elite plants were used as the source of explants. New axillary shoots were obtained after 30 days of culture on a MS medium supplemented with BAP (2.0 mg·L⁻¹) and NAA (0.1 mg·L⁻¹). The optimal multiplication medium was a modified MS medium supplemented with BAP (1.0 mg·L⁻¹) and NAA (0.1 mg·L⁻¹). This yielded a multiplication rate of 2.4 for each subculture. Slightly more than 92% of shoots rooted when cultured on a modified MS medium containing IBA (0.2 mg·L⁻¹) and activated charcoal (0.5 mg·L⁻¹). Activated charcoal promoted both a strong and a high rooting rate during the rooting phase. Plantlets were transferred to pots for a short acclimatization stage in a greenhouse where 95% of the plantlets survived. This highly reproducible procedure can be adopted for large-scale propagation of T. wilfordii.