Background : Licorice (Glycyrrhiza uralensis F.) is one of the most widely used raw materials for food and pharmaceuticals, and is currently the No. 1 imported medicinal plant in Korea. Efforts to settle licorice cultivation in Korea have been carried out for hundreds of years but have not succeeded, and many people suspect that the reason is due to the inadequate cultivation environment. However, even until recently, most licorice has been procured by wild harvesting, so studies on licorice cultivation technique and cultivation environment have not been conducted much in the world. This experiment was conducted to investigate the germination characteristics of licorice by temperature and salt concentration in order to find the optimal cultivation environment conditions of licorice.
Methods and Results : The germination rate of licorice seeds was high 77.5 - 90.5% at 10 - 3 6℃, but it started to drop from 66.5 - 68.0% at 38 - 40℃ and it decreased sharply from 9.0 - 15.0% at 42 - 46℃. No longer germinated at temperatures above 48℃. The average number of days of germination was 12.3 days at 10℃, 5.7 days at 20℃, 3.5 days at 30℃ and 4.1 days at 40℃. The germination start date was 2 to 4 days in the 18℃ - 46℃ range. The average germination rate was the highest at 32℃. The germination time of 40% was 2 - 4 days at 18 - 46℃. The germination of more than 80% took 3 - 5 days at 20 - 40℃, 6 - 8 days at 14 - 1 8℃ and 10 days at 10 - 12℃. Licorice was able to germinate even in the presence of salt. Seed germination rate was 78.5 - 85.5% at 0 - 1% salt concentration and 63% at 1.5% and 18% at 2.0%. In addition, 8.5% seeds germinated successfully even at 3.0% salt concentration.
Conclusion : Licorice has been known as a low temperature crop, but germination was possible in a wide range of temperature and salt concentration. Especially, the germination characteristic was higher in the high temperature range of 30 - 36℃, which corresponds to the domestic summer temperature. Therefore, the results of this study are expected to be useful reference for exploring suitable cultivation area in Korea.