Effects of Gibberellic Acid and Alternating Temperature on Breaking Seed Dormancy of Panax ginseng C. A. Meyer

Abstract

Background: Developing new ginseng cultivars is a significant time-consuming process owing to the three years of growth required for ginseng to flower. To shorten the ginseng breeding process, it is necessary to establish rapid progression through each generation. In this study, we examined it was possible to rapidly break ginseng seed dormancy using gibberellic acid (GA₃) treatment and alternating temperature. Methods and Results: Seeds were obtained from local variety. Seeds were treated with either GA₃ at a concentration of 100 ㎎/ℓ, constant temperature (−2℃ and 2℃), alternating temperature (2℃ followed by −2℃, followed by 2℃) or a combination GA₃ and temperature treatment. Following experimental treatment, seeds were sown into trays and placed in a greenhouse. Low germination rates were observed in seeds that did not receive GA₃ treatment, which were similar following 2℃ and −2℃ constant temperature treatment. Germination rates increased in proportion to GA₃ and more so when combined with alternating temperature treatment. In additon, stem and leaf lengths of the resulting ginseng plants were increased following GA₃ treatment, although no synergistic effect was observed with alternating temperature treatment. Conclusions: These results suggest that a combination GA₃ and alternating temperature treatment enhances ginseng seed germination, which can contribute to shortening the time required to progress through a single ginseng generation for breeding.