Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 45 3 2014 09 23 Reduce the Adverse Effects of Salinity On some Physiological Characteristics of Three Rapeseed (Brassicc napus) Cultivars under Elevated Atmospheric Concentration of Carbon Dioxide Reduce the Adverse Effects of Salinity On some Physiological Characteristics of Three Rapeseed (Brassicc napus) Cultivars under Elevated Atmospheric Concentration of Carbon Dioxide 473 487 53558 10.22059/ijfcs.2014.53558 FA Abbas Dehshiri Ph.D. Student in Crop Science, Agronomy Department, Faculty of Agriculture, Tarbiat Modares University, Tehran Seyed Ali Mohammad Modarres-Sanavy Professor in Crop Science, Agronomy Department, Faculty of Agriculture, Tarbiat Modares University, Tehran 0000-0003-2037-0271 Journal Article 2012 10 13 In order to evaluate the effects of atmospheric CO₂ concentration increment on rapeseed salinity tolerance, four levels of salinity(0, 5, 10 and 15 dS.m^-1) on  three cultivars of rapeseed (Okapi, Zarfam, and RGS) at three levels of atmospheric CO₂ concentration(350, 700 and 1050 ppm) were studied. The experiment was conducted at the greenhouse of Tarbiat Modares University at 2010 and 2011 crop season. Three levels of CO₂ concentrations have been considered as three environments in which two other treatments (salinity and cultivar) carried out in a completely block design in factorial arrangement. Results indicated that photosynthesis rate of canola increased with increasing CO₂ Concentration (about three times in 1050ppm) in the air and decreased with increasing salinity (21% in 15 dS.m^-1). Three times concentration of CO₂(1050ppm) reduced the impact of salinity on photosynthesis. Elevated CO₂ by increasing photosynthesis rate, reducing transpiration and increasing water use efficiency reduced effects of salinity. Water use efficiency was increased with increment concentration of carbon dioxide and decreased with salinity. In order to evaluate the effects of atmospheric CO₂ concentration increment on rapeseed salinity tolerance, four levels of salinity(0, 5, 10 and 15 dS.m^-1) on  three cultivars of rapeseed (Okapi, Zarfam, and RGS) at three levels of atmospheric CO₂ concentration(350, 700 and 1050 ppm) were studied. The experiment was conducted at the greenhouse of Tarbiat Modares University at 2010 and 2011 crop season. Three levels of CO₂ concentrations have been considered as three environments in which two other treatments (salinity and cultivar) carried out in a completely block design in factorial arrangement. Results indicated that photosynthesis rate of canola increased with increasing CO₂ Concentration (about three times in 1050ppm) in the air and decreased with increasing salinity (21% in 15 dS.m^-1). Three times concentration of CO₂(1050ppm) reduced the impact of salinity on photosynthesis. Elevated CO₂ by increasing photosynthesis rate, reducing transpiration and increasing water use efficiency reduced effects of salinity. Water use efficiency was increased with increment concentration of carbon dioxide and decreased with salinity. https://ijfcs.ut.ac.ir/article_53558_0bd1cce5c59b8d2ac79a613bc71209e2.pdf