Plant regeneration of ‘Wongam’ ( <i>Glycyrrhiza glabra</i> × <i>Glycyrrhiza uralensis</i> ) using nodal explants

This study established an efficient in vitro propagation and acclimatization system for the newly developed licorice cultivar 'Wongam' (Glycyrrhiza glabra G. uralensis).Wongam is an interspecific hybrid licorice cultivar recently developed in Korea, characterized by its higher yield, increased glycyrrhizin content, and improved resistance to lodging and leaf spot disease compared to G. uralensis.In the initial culture using nodal explants, the Murashige and Skoog (MS) medium supplemented with 0.05 mg/L ascorbic acid, 1.0 mg/L 6-benzylaminopurine (BAP), and 0.2 mg/L indole-3-butyric acid (IBA) produced the best results, achieving 100% shoot induction, an average shoot length of 3.2 cm, and 2.6 stems per explant.During the multiplication stage, MS medium containing 2.0 mg/L thidiazuron (TDZ), 0.1 mg/L IBA, and 0.03 mg/L gibberellic acid (GA 3 ) yielded 3.4 shoots per explant and a shoot length of 5.1 cm.The highest survival rate (100%) was seen with Gamborg's B5 medium.Root induction was the most successful using the B5 medium supplemented with 0.1 mg/L naphthaleneacetic acid (NAA) and 0.05 mg/L zeatin.This resulted in a rooting rate of 95.8%, five roots per explant, a root length of 12.6 cm, and 100% survival.In the acclimatization phase, a 50:50 (%) mixture of perlite and vermiculite achieved the highest survival rate (100%) and shoot length (10.2 cm).These results indicate that specific combinations of plant growth regulators, medium type, and soil mixture ratio are key factors for the large-scale propagation and stable acclimatization of Wongam licorice plantlets.This provides a practical basis for industrial tissue culture and the production of high-quality medicinal plants in Korea.