Shoot regeneration and micropropagation of Panax vietnamensis Ha et Grushv. from ex vitro leaf-derived callus

Abstract

The methods for leaf-derived callus induction, callus proliferation, adventitious shoot induction and plant regeneration of Vietnamese ginseng (Panax vietnamensis Ha et Grushv.) were examined. In this study, callus induction was formed on both medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination with thidiazuron (TDZ). The highest callus induction frequency was obtained on Murashige and Skoog (MS) medium supplemented with 1.0 mg/l 2,4-D and 0.2 mg/l TDZ. The best callus proliferation medium was Schenk and Hildebrandt (SH) supplemented with 0.2 mg/l TDZ and 1.0 mg/l 2,4-D. The maximum callus-derived shoot number (8.2) was obtained on SH medium supplemented with 50 g/l sucrose in combination with 2.0 mg/l 6-benzylaminopurine (BA). The most successful rooting of regenerated adventitious shoots was obtained on SH medium with 1.0 mg/l α-naphthalene acetic acid (NAA). Plantlets were successfully acclimatized without growth chamber facility on Ngoc Linh mountain with a survival rate of 85% after two months. On the other hand, substantial increase of root length was observed. This study describes an efficient method for in vitro regeneration of P. vietnamensis, which could be considered for large-scale multiplication and propagation of this important medicinal plant.

Key words: Acclimatization, callus, Panax vietnamensis, regeneration, root, shoot.