Somatic Embryogenesis and Plantlet Regeneration from Hairy Roots Transformed by Agrobacterium rhizogenes in Panax quinquefolium L

Here, efficient plantlet regeneration via somatic embryogenesis from Panax quinquefolium hairy roots was reported. Callus development was optimal on MS medium containing 2,4-dichlorophenoxyacetic acid (1 mg l) and -naphthalene acetic acid (1 mg l). After a 4-week growth, calli were transferred onto MS medium with different combinations of plant growth regulators (PGRs). The highest embryogenesis frequency (~55%) of the calli occurred with 0.5 mg l 2,4-dichlorophenoxyacetic acid after an additional 2-month culture. During embryos germination, different media with 3 mg l gibberellin were evaluated for plantlet rooting. It was indicated that the suitable medium was 1/2 MS among the media tested. Furthermore, different PGRs were appraised for plantlet rooting using 1/2 MS medium. The data implicated that abscisic acid (0.5 mg l) could play a role in promoting plantlet rooting. _____________________________________________________________________________________________________________