Cell Biology and Morphogenesis

An efficient in vitro protocol for plant production of North American ginseng has been established. The pretreatment of cotyledon explants with 1.0 M sucrose at 4◦C resulted in an improvement of embryo quality and, combined with a higher sucrose content (7%) in induction medium, improved the embryogenesis frequency from 40% to 75% and the number of embryos per explant from 10 to 21. The frequency of secondary embryogenesis from somatic embryo-derived tissues cultured on MS medium with 1.0 mg l−1 2, 4-D and 1.0 mg l−1 NAA is up to 90%. Somatic embryos can further develop to maturity on SH medium supplemented with 1% activated charcoal and half of them can germinate. About 85% of the germinated embryos will convert into plants with well-developed taproot systems on /2 SH medium with 0.5% activated charcoal. The growth chamber and field establishment rates were 95.6 and 93.7%, respectively. The plants transplanted to growth chambers and field plots appear normal.