PRODUCTION OF SOMATIC EMBRYOS OF AMERICAN GINSENG IN SUSPENSION CULTURE AND REGENERATION OF PLANTLETS

American ginseng (Panax quinquefolius L.) is widely grown in Canada as a source of vitalizing and stimulating agents.
The slow-growing nature of this plant and the 4-yr reproductive cycle make breeding efforts to select for desirable traits difficult.
A tissue culture method to clonally propagate ginseng has potential to overcome these restrictions.
A range of ginseng seed sources was evaluated for response to tissue culture conditions.
Leaf and stem explants were placed on Murashige and Skoog (MS) medium with 10 μM NAA and 9 μM 2,4-D. Callus developed after 3 wk in darkness and by 10 wk, embryos were observed on all lines and the cultures were transferred to light.
Embryogenic suspension cultures were initiated in MS liquid medium containing 2.5 μM NAA and 2.25 μM 2,4-D.
Subcultures were made every 8 wk and large numbers of somatic embryos were produced.
Somatic embryo pre-treatments were assessed to enhance embryo germination and conversion.
Desiccation for 3 d to achieve an average of 70% water loss or placement of embryos in 50 ml half-strength MS with 1% charcoal at 140 rpm for 7 d both enhanced overall germination and germination rate.
Treatment of germinants with 3 μM GA and 5 μM BA for 7 d in low light followed by incubation on half-strength MS with 1% charcoal for 15 d promoted further shoot development.
Plantlets were obtained and transferred to Magenta boxes containing vermiculite saturated with half-strength MS liquid.