Micropropagation and β-ecdysone content of the Brazilian ginsengs Pfaffia glomerata and Pfaffia tuberosa

The aim of this study was to investigate both a mass in vitro propagation system and the beta-ecdysone content in roots and aerial parts of Pfaffia glomerata and Pfaffia tuberosa. Nodal segments of two genotypes (BRA and JB-UFSM) of P. glomerata, originated from aseptically grown plants, were cultivated on hormone-free Murashige and Skoog medium. For the proliferation of P. tuberosa shoots, nodal segments, originated from aseptically grown plants, were either cultivated on hormone-free Murashige and Skoog (MS) medium or were supplemented with 1.0 A mu M thidiazuron (TDZ); the elongation and rooting of these plants were carried out on MS medium without TDZ. Plantlets of both species were acclimatized and transferred to field conditions. The beta-ecdysone content in the plants was determined by high performance liquid chromatography. The BRA genotype showed a greater in vitro proliferation rate and beta-ecdysone content than that of the JB-UFSM genotype. The culture of nodal segments of P. tuberosa on medium with 1.0 A mu M TDZ with subsequent subcultivation of shoots on hormone-free medium was shown to be a suitable method for micropropagation due to the high multiplication rate and good plant development. Both species showed good adaptation to ex vitro conditions. The beta-ecdysone content in micropropagated P. tuberosa was similar to that found in field-grown plants. For both species, the aerial parts accumulated higher beta-ecdysone content than roots. These results reveal that micropropagation is a successful, alternative method for rapid plant multiplication of both species of Brazilian ginseng. Furthermore, this study demonstrates that these two species have a potential for cultivation that is associated with high beta-ecdysone production.