In Vitro Conditions Research of Sophora koreensis Nakai for Shoot Elongation

Sophora koreensis Nakai, listed as endangered on the IUCN Red List, is a species native to Korea, specifically found in parts of Gangwon-do. Recent research highlights its potential in hangover relief and as an antioxidant source, sparking interest in enhancing its components through mutation for commercial purposes. Given its limited distribution, micropropagation of S. koreensis is essential for its economic exploitation. This study focuses on in vitro culture to develop an elongation system for micropropagation. The hormonal combination of 6-benzylaminopurine (2 μM), thidiazuron (2 μM), and indole-3-butyric acid (0.5 μM) produced the highest number of shoots (14) with an average length of 0.7 cm compared to the control. Additionally, adjusting photoperiod conditions under specific culture media further increased shoot length to 0.6 cm, which was also higher than that of the corresponding control group under standard light conditions. However, survival rates were generally low across all treatments during subculture. Isolating and individually culturing induced explants resulted in shorter shoots and lower survival rates. Improvements were noted when explants with 10 shoots were subcultured, achieving an 83% survival rate, with an average of 4.93 shoots at 0.95 cm in length. Rooting was most successful with 10 μM IBA, also showing the highest root number, indicating a potential pathway for enhancing micropropagation efficiency.