Regeneration of Panax ginseng C.A.Meyer by organogenesis and nuclear DNA analysis of regenerants

Plant regeneration ability of ginseng (Panax ginseng C.A. Meyer) via organogenesis was studied. Compact callus was induced from four different types of explants-leaf, petiole, flower stalk, and root of in vitro-grown plantlets. Petioles were found to be the best material for callus induction. Calli induced on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (4.5 mu M) and kinetin (0.46 mu M) were conditioned for two weeks on the same medium. These calli differentiated into adventitious shoots when cultured on 1/2MS basal medium plus kinetin 4.7 mu M and silver thiosulphate 10 mu M. An addition of GA(3) (2.9 mu M) and BA (4.4 mu M) to MS basal medium, however, induced high frequency in vitro flowering (86.1%) and multiple shoot budding which affected the normal complete development of plantlets. Plantlets with a well-developed root system were obtained six weeks after regenerated shoots had been transplanted to 1/2 MS20 medium containing IBA 1.2 mu M. Nuclear DNA content was measured to check the stability of their ploidy level. Based on DNA flow cytometric analysis, all the regenerants were typically diploids as the mother plants were, indicating that nuclear DNA content remained stable during cell differentiation.