Response of Dracocephalum kotschyi to Different Light Intensities and Combinations under In-Vitro Conditions

Recent advances in biotechnology, especially tissue culture of plants under various light conditions, have provided a good platform for the production of secondary metabolites. The present study aims to investigate the effect of intensity and different light qualities on in vitro growth and production of secondary metabolites in Dracocephalum kotschyi plant. The evaluated morphological traits included the number of regenerated plantlets, plantlet height, leaf area, the number of roots and leaves. Also, the measured biochemical traits were total phenol and flavonoid contents, chlorophyll a and b, carotenoid, total protein and FRAP antioxidant. The results showed that the combination effect of red and blue light improves the growth and biochemical indices, so that the highest regeneration rate and number of leaves was attained in combined 80% Red + 20% blue light treatment. the highest amount of total protein (15.36 mg/g FW), total phenol (606.13 mg GA / g FW), chlorophyll a (7.73 mg / g FW) and carotenoids (2.78 mg / g FW) were obtained in combined light treatment of 60 % red + 40% blue. In general, the results obtained in the present study showed that the combination of red and blue light, compared to white light, has effectively improved the morphological and biochemical indices of Dracocephalum kotschyi plant.