Photosynthetic and nonphotosynthetic pigments of two rose cultivar under different light intensities

Biosynthesis of plant pigments are affected by environmental factors including light. Chlorophyll content of plant changes to absorb maximum photons, and different light intensities affect phenolic’s metabolism including anthocyanins. This study was conducted to evaluate the effect of different light intensities on photosynthetic and non photosynthetic pigment of rose during 2011. In this study, the effects of different light intensities include 240, 520, 640 mol m-2s-1 and control with 1200 molm-2s-1 (without application of plastic nets) on two rose cultivars was evaluated under greenhouse condition. Plastic nets were used to obtain different levels of light intensities. The results showed that photosynthetic pigments, chlorophyll and carotenoids, were significantly (p≤0.01) increased in light intensity of 240 molm-2s-1 compared with control. In this light intensity antocyanin content was significantly reduced. Reducing light intensity to 240 molm-2s-1 could result in higher chlorophyll as well as carotenoid content without significant changes in flavonoids. Increasing anthocyanin content with increasing light intensity to 1200 molm-2s-1 could be a defense mechanism in plants against toxic levels of light intensities.