EFFECT OF LEVEL OF PFD ON PHOTOSYNTHETIC PARAMETERS AND PRODUCTION OF STEVIOL GLYCOSIDES BY HYDROPONIC CULTURE FROM STEVIA REBAUDIANA BERTONI

Stevia rebaudiana produces steviol glycosides (GSt) 300 times sweeter higher than sugar cane. The problem is that the global demand is increasing and the agricultural production is insufficient. Is reported that Hydroponic cultivation and high irradiance increase the yield of S. rebaudiana and the production of steviol glycosides. This is due to the management and control of nutrition and the effect of light on the photosynthetic system, respectively. Therefore, the objective was to evaluate the effect on three levels of PFD (440.8, 383.9 and 273.2 μmol m-2 s) efficiency of photosystem PSII, and production of glycosides of steviol in S. rebaudiana var. Morita II at 40 and 90 days, using a NFT hydroponic culture (Nutrient Film Technique). The highest photosynthetic rate was recorded at 440.8 μmol m-2 s with 15.4 and 17.72 ppm CO2 min-1 g at 40 and 90 of culture days respectively and the higher content of steviol glycosides, with this same PFD, the lowest fluorescence emission occurred in PSII, while with low luminosity, the absorbed energy was harnessed more efficiently by the PSIIRC. The photosynthesis and production of steviol glycosides in S. rebaudiana were affected by level of PFD and culture time in a hydroponic system.