Modification of light quality improves the growth and medicinal quality of clonal plantlets derived from the herbal plant Gentiana

Abstract

Gentians are medicinal plants whose roots and rhizomes have been used as natural medicines for ga strointestinal problems. �e active components are bitter compounds known as secoiridoid glycosides such as gentiopicrin and swertiamarin. Previously, procedures for the in vitro clonal culture of gentian plantlets were established. In this study, the eect of dierent wavelengths of light emitted by LED on plantlet growth and the concentrations of active components w as investigated. We found that plantlet growth was promoted aer irradiation with red light. Because a similar trend was observed in all gentian cultivars tested, the improved eect of red light on plantlet growth seemed to be a common characteristic of Gentiana species. We also found that both leaves and roots of the plantlets contained gentiopicrin and swertiamarin. Gentiana triora 'M aciry' had the highest concentration of both compounds compared with several gentian lines and cultivars. Furthermore, the concentrations of roots were increased by far-red and blue light irradiation. �ese results suggest that modication of light quality by LED is an eective strategy for improving the growth and concentration of active components in gentian plantlets that can be used as a novel ingredient in natural medicine.