Study on some physiology characteristics and growth of Stevia rebaudiana Bertoni in vitro in LED monochromatic light system and green house stage

This study aims to evaluate the growth and dry matter accumulation of stevia grown in lighting conditions with different spectral ratios, thereby finding the most suitable lighting rate. Materials are stevia stalks cultured in shoot medium, including: MS base supplemented with 20 g\Lsucrose; 8 g\Lagar; 0.15 mg\LBAP, 0.2 mg\LNAA, cultured for 4 weeks under a LED system with different color light ratios, using the following formulas: 40% red + 20% blue + 40% orange (CT1), 20% red + 20% blue + 60% yellow (CT2), 72% red + 14% blue + 14% white (CT3) and 80% red + 20% blue (CT4) and the control formula was the formula of fluorescent lamp irradiation (DC). Formula CT4 gave a result of 100% shoot formation, the average height of shoots was 48.5 mm\shoot and the shoots were the best in quality. Rooting medium included: MS basal supplemented with 15 g sucrose, 8 g\Lagar, 0.2 mg\LNAA for 4 weeks. The results also showed that the CT4 lighting formula was the most suitable for the photosynthesis and growth of cultured stevia in the rooting stage. The seedlings from this lighting system when grown in the net house were able to survive and grow better than the plants from the other lighting conditions.