Mansoureh Hatamian; Mostafa Arab; Mahmoud Reza Roozban
Abstract
Light as an important environmental factor, influences many aspects of plant growth and development. Leaves are different in some characters including stomatal behavior under shade or light conditions. In this study, the effects of different levels of light intensity on stomatal behavior of two rose ...
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Light as an important environmental factor, influences many aspects of plant growth and development. Leaves are different in some characters including stomatal behavior under shade or light conditions. In this study, the effects of different levels of light intensity on stomatal behavior of two rose cultivars, ‘Gulmira’ and ‘Red One’, were evaluated under controlled conditions. To obtain different light intensities, green polyethylene nets were used. Treatments were light intensities of 1200 (Control), 640, 520 and 240 mmol/m2/s. Based on the results, the highest stomatal length and width were found in 640 mmol/m2/s in both cultivars. Regarding stomatal density, there were no significant differences among different levels of light intensities, although cultivar effect was significant. Therefore, stomatal density was higher in ‘Gulmira’ than ‘Red One’. Also, stomatal conductance was significant only between cultivars, and there was no significant difference among light treatments. However there was an increasing trend of stomatal conductance with increasing light intensities.
Mansoure Hatamian; Mostafa Arab; Mahmoud Reza Roozban
Abstract
Biosynthesis of plant pigments is affected by environmental factors especially light intensity. An expriment was conducted to evaluate the effect of different light intensities on photosynthetic and non-photosynthetic pigments of two rose cultivars including ‘Red One’ and ‘Gulmira’ ...
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Biosynthesis of plant pigments is affected by environmental factors especially light intensity. An expriment was conducted to evaluate the effect of different light intensities on photosynthetic and non-photosynthetic pigments of two rose cultivars including ‘Red One’ and ‘Gulmira’ under greenhouse conditions. In this experiment, the effects of different light intensities including 240, 520 and 640 mol/m2/s and control with 1200 mol/m2/s (without application of plastic nets) on the rose cultivars was evaluated under greenhouse conditions. Plastic nets were used to obtain different levels of light intensities. The results showed that photosynthetic pigments, chlorophyll and carotenoids, significantly increased in the light intensity of 240 mol/m2/s vs. control. In this light intensity, antocyanin content was significantly reduced. Reducing light intensity to 240 mol/m2/s could result in higher chlorophyll as well as carotenoid content without significant changes in flavonoids. Increasing anthocyanin content with increasing light intensity to 1200 mol/m2/s could be a defense mechanism in plants against toxic levels of light intensities.