Effect of cadmium on some physiological parameters in different safflower genotypes under hydroponic conditions

To investigate the effect of cadmium (Cd) on some physiological parameters of safflower genotypes a 3-replicate factorial randomized complete blocks experiment was conducted under hydroponics culture in greenhouse facilities of the Isfahan University of Technology in 2012. Four levels of Cd (control (0)، 1. 5، 3. 0 and 4. 5 mg/L) were tested on six safflower genotypes (Arak2811، Kouseh، Nebraska-10، C111، K12 and S149). Physiological characteristics such as leaf number/plant، leaf fresh weight، shoot fresh weight، root volume، shoot dry weight، root dry weight and Cd concentration in plant roots and shoot were measured. Results indicated that in higher Cd concentrations in the solution، negative effects of Cd on different plant traits were more visible. Safflower plants showed 61. 2، 37. 5 and 71. 8 percent decrease in their root length، leaf number/plant and root volume، respectively، and 52- and 156-fold increase in their shoot and root Cd concentration، respectively، when grown under the 4. 5 mg/L of Cd in the solution، compared to the control. Cd concentration of plant shoot was profoundly lesser than that of plant roots for all studied genotypes. It was concluded that while Cd leads to considerable changes in growth and physiological attributes of safflower، but some differences exist among safflower genotypes.