Establishment of an efficient protocol for rapid propagation of Chinese foxglove (Rehmannia angulata)

An effective micropropagation protocol has been established to rapidly propagate Chinese foxglove R. angulata. Callus was successfully induced from the explants of hypocotyls on media containing 0.5 mg l⁻¹ BAP and 0.4 mg l⁻¹ NAA; and then adventitious shoots differentiated on the media supplemented with 1 mg l⁻¹ BAP and 0.5 mg l⁻¹ NAA at the initial stage. In shoot proliferation stage, a newly developed Formula β (A+B) based media was more effective than MS salts based media to induce new shoots by approximately regenerating twice as many shoots per explant, while the multiplication rate of roots was nearly three times higher in Formula β than in MS after eight-week culturing. There was no significant influence on the induction of shoots and roots between conventional culture plasticware and a new type of culture container made of high-density polyethylene bags. The roots were induced and formed in the multiplication media after eight weeks of culture before transplanting in the glasshouse and resulted in an efficient and simplified propagation procedure of in vitro culture integrated with white polythene material protection to give stronger and healthier transplantations at the acclimation stage.