پیامد افزایش غلظت دی اکسیدکربن هوا بربرخی ویژگیهایچهارژنوتیپ برنج در شرایط تنش شوری

Thisstudy was designed in research greenhouse of Isfahan University of Technology during autumnand winter2013 toinvestigate the response ofseedling growth of fourrice genotypes (Shirodi, Neda, Deylamani and Domsorkh) underfour levelsof sodium chloride (0, 30, 60, 90mMin theYoshida nutrient solution), and at two levels of ambient(360±50 µM) andenriched(700±50 µM) carbondioxide. The experiment was arranged as factorialin a randomized complete block designwithfour replications. The results showed that there was significant variation among rice genotypes in response to different salinity and air CO2 levels. Under non-saline conditions, rising concentrations of carbon dioxide, made increases in shoot dry matter in Shirudi (33%), Neda (50%), Daylamani (80%) and Domsorkh (33%) and shoot dry weights reached 0.4, 0.3, 0.9 and 0.8 g plant-1, respectively. While, root dry weight of Shirudi and Neda was not affected by increased level of carbon dioxide, but it was increased by 60 and 50% in Daylamani and Domsorkh, respectively. The negative effect of salinity on dry weights of rice genotypes was alleviated with increasing level of carbon dioxide. At 360 µM air CO2 concentrationdry matter of Shirudi and Neda were not affected by different levels of salt stress. However, dry weights of Daylamani and Domsorkh were reduced by 40 and 50%, respectively, under saline compared to non-saline conditions.