عنوان مقاله [English]
To comparison the photosynthetic parameters and leaf chlorophyll content and fluorescence of safflower (Carthamus tinctorios L.) cultivars under salinity stress, a pot experiment was carried out as factorial based on completely randomized design with three replications in summer 2011 in University of Yasouj. First factor included four salinity levels (zero, 75, 150 and 225 mM (formed as 20 to 1 mM, NaCl to CaCl2, in Hoagland solution) and the second factor included six cultivars of safflower (Local Isfahan, Spinned Sina, Isfahan 14, Goldasht, Padideh and Sina 411). Photosynthetic parameters including photosynthesis rate, transpiration, stomatal conductance, mesophyll conductance, chlorophyll content and chlorophyll fluorescence components were measured. Results showed that the interaction of cultivar and salinity for all traits, except for Fv/Fm, were significant. Decreased trend of chlorophyll and photosynthetic parameters with increasing salinity was different for cultivars. F0 and Fm were increased with increasing salinity levels in all cultivars. Based on our results, at zero salinity level Padideh had relative superiority in terms of chlorophyll a, chlorophyll b, transpiration rate, photosynthetic rate and water-use efficiency. At 75 mM salinity, Spinned Sina had relative superiority in terms of chlorophyll b, total chlorophyll, carotenoids, and photosynthesis rate compared to other cultivars. At 150 mM salinity, Padideh had relative superiority in terms of chlorophyll a, chlorophyll b, the rate of photosynthesis and water use efficiency than other varieties and 225 mM salinity level, Isfahan 14 in terms of chlorophyll a, chlorophyll b, carotenoids, assimilation rate and water use efficiency was better than other varieties.