EFFECTS OF LIGHT QUALITIES ON GERANIIN PRODUCTION OF GERANIUM THUNBERGII
The purpose of this study is to investigate geraniin production of Geranium thunbergii grown under different light qualities. G. thunbergii is a traditional medicinal plant which has been used as gastrointestinal drug in Japan. The main medicinal property of G. thunbergii is geraniin, which is a form of tannin. Productivity of geraniin was evaluated under three different light qualities, which were red light emitting diodes (LEDs) with a peak wavelength of 660 nm, a combination of red LEDs and blue Cold Cathode Fluorescent Lamp (CCFL) with a peak wavelength of 450 nm, and Cool White Fluorescent Lamp (CWF) as a control. A continuous 24-hour light photoperiod was employed. A photosynthetic Photon Flux Density of 50 µmol m-2 s-1 was applied for each of the three light quality conditions. Plants were grown under a NFT hydroponic system with Otsuka type-A nutrient solution for 60 days. The concentration of geraniin was then quantitatively measured using HPLC. In this study, geraniin concentration was highest in the red light condition, followed by the red and blue light condition, and lastly the CWF condition. The results suggested that red light might have stimulated production of geraniin. However, in terms of total volume per plant, G. thunbergii grown under CWF showed the highest productivity.
Watanabe, H., Namiki, K., Nemoto, S., Tajima, M., Ono, E. and Amaki, W. (2011). EFFECTS OF LIGHT QUALITIES ON GERANIIN PRODUCTION OF GERANIUM THUNBERGII. Acta Hortic. 907, 111-114
CCFL, LED, light condition, medicinal plant, NFT hydroponics