Phytochemical Assessment and Comparison of some Iranian Licorice (Glycyrrhiza glabra L.) Populations in Field Conditions

Licorice is a perennial herbaceous plant belonging to the Fabaceae family which possesses several medicinal properties, such as antioxidant, antimicrobial, antiviral, anti-inflammatory, and anticoagulant properties. It is an invaluable and strategic plant in Iran, and Iran is one of the major exporters of licorice roots.
In this study, the diversity of phytochemical traits, among different Iranian licorice landraces cultivated in field conditions, was investigated. Rhizomes of different populations were collected from different regions of Iran in 2019 and were planted in a randomized complete block design with five replications in the medicinal plants collection of Shahid Beheshti University. The studied traits were glycyrrhizic acid, glabridin, liquiritigenin, liquiritin, rosmarinic acid, rutin, total phenol, total flavonoids content and antioxidant activity. The highest content of glycyrrhizic acid (155.17 mg/g dry weight) and glabridin (19.46 mg/g dry weight) were observed in Kazerun and Ilam population, respectively. The population of Yasuj had the highest amounts of liquiritin (5.32 mg/g dry weight) and liquiritigenin (12.16 mg/g dry weight). A positive and significant correlation was observed between glabridin and liquiritin content at 5% probability level, but it had a significant negative correlation with IC50 at 5% probability level. Based on the results of cluster analysis, 22 licorice populations divided into five main groups. Factor analysis showed that the first four factors explained 69.21% of the total variance. Overall, the findings of this study showed that the studied licorice populations had unique phytochemical properties that can be used in breeding programs, and also in the pharmaceutical industry.