Background : Panax ginseng C. A. Meyer is an important medicinal herb and their major pharmacologically active components are ginsenosides. Many studies have reported that various ginsenosides are effective in the treatment of human diseases such as cancer, cardiovascular and alzheimer’s disease. However, it is difficult to create new desirable variation such as increased ginsenosides. Since the frequency of spontaneous mutations is rare naturally and difficult to apply to plant breeding, artificial mutation inductions are necessary to obtain noble genetic resources having desirable traits.
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. One-year-old ginsengs were treated at 20, 40, 60, 80, and 100 Gy. The emergence rate was significantly decreased with increasing gamma doses. When irradiated at more than 80 Gy, it did not emerge at all. Survival rate was also significantly influenced by gamma-ray dose. The maximum survival rate were recorded in control. The survival rate of 20 Gy was 22.0% and only 1.0% survived when 40 Gy dose was treated. There was no survival when irradiated at more than 60 Gy. Gamma irradiation also affected the phenotype of emerged plants. The growth of plants derived from irradiated one-year-old ginsengs was decreased and the leaves became variegated or curled. Also, rusty roots resulting from physiological disorders were observed and the rhizomes, which is a kind of dormant bud, were destroyed completely.
Conclusion : Based on these results, we estimated the optimal dose for mutation induction by gamma-ray treatment of one-year-old ginseng is to be less than 20 Gy.