Effects of GA₃ and Alternating Temperature on Breaking Bud Dormancy of Panax ginseng C. A. Meyer Seedling

인삼 묘삼 휴면 조기타파에 미치는 GA₃ 및 변온 처리 효과

Background : Considerable time and effort is required to develop new Panax ginseng varieties. Ginseng breeders have been developing techniques to shorten the breeding cycle to resolve this problem. In this study, we investigated the effects of adding $GA_3$ and alternating temperature (AT, $2^{\circ}C{\rightarrow}-2^{\circ}C{\rightarrow}2^{\circ}C$) on breaking bud dormancy in the varieties (Chungsun and Sunun) of ginseng root. Methods and Results : The $GA_3$ soaking treatment and AT were applied to one year old roots, which greatly accelerated the emergence of new buds. In one year old roots, new buds emerged from the 4th day post transplanting and after breaking dormancy with $GA_3$ and AT treatments. The emergence of new buds was completed within two weeks. The rate of bud emergence for Chungsun was 60% - 98% over 15 - 60 days after the AT and $GA_3$ treatments. The emergence rate of Sunun was 46% - 92%. Normal growth of the ginseng seedling was observed in spite of the early breaking of bud dormancy by combined $GA_3$ and AT treatments. Conclusions : $GA_3$ and AT treatments shortened the dormancy period and facilitated the stable emergence of ginseng seedlings. However, some plants suffered deformities and early sprouting owing to the combined $GA_3$ and AT treatments. Early sprouting was free from dormancy after leaf fall from the of aerial part of the plant.