Background : Mutagenesis is one of the most powerful method for genetic variation, however there is little research history in P. ginseng. The seeds and vegetative tissues are materials commonly used for mutagenesis, but there is a problem that chimeras known as sectoral differences can occur and unintentional poor selection can occur owing to the influence of the growth environment. The combination of in vitro culture and mutagenesis can eliminate the effects of the environmental factors.
Methods and Results : Gamma irradiation was carried out using a 60Co irradiator (3000Ci, Nordion Inc., Ottawa, Canada) of the Korea Atomic Energy Research Institute, Jeongeup, Korea. The explants containing the somatic embryos were treated with 20, 40, 60, 80, and 100 Gy. Gamma-rays affected the somatic embryos produced in vitro depending on the dose. The survival rate of somatic embryo was significantly influenced by gamma irradiation. Also, the development of the embryo was changed by gamma irradiation depending on each dose. When somatic embryos were transferred to the medium supplemented with GA3, they started to germinate but were affected significantly by gamma irradiation dose. When germinated shoots were transferred to 1/2 SH medium to induce rooting, as the concentration of gamma ray treatment increased, the rooting gradually decreased.
Conclusion : Considering the overall survival rate, germination rate, embryo development, and rooting rate, the optimal dose of gamma rays to be used with somatic embryo is estimated to be between 60 Gy and 80 Gy.