Safflower ( Carthamus tinctorius L.) Response to Cadmium Stress: Morpho-Physiological Traits and Mineral Concentrations.

Cadmium is a widely distributed heavy metal in agricultural soils that affects plant growth and productivity. In this context, the current study investigated the effects of different cadmium (Cd) doses (0, 25, 50, 75, and 100 mg L -1 of CdSO 4 ) on the growth and physiological attributes of safflower ( Carthamus tinctorius L.) including plant height (cm), root length (cm), fresh weight (g) of root, stem, and leaves, leaf number, macro and micro-nutrients, Se, and heavy metal (Cd, Cr, and Pb) content. The experiment was carried out in a completely randomized design (CRD) with four replicates. The results showed that Cd stress significantly negatively affected all growth indices, macro- and micro-nutrients, and heavy metal content. In addition, it increased the MDA and APX activities. The highest amounts of Fe, Mn, Ni, Pb, Zn, K, Na, Cd, Cr, and Cu were determined in plant roots, while the highest values of Ca and Mg were detected in plant stem tissues. High Cd doses decreased the content of Ca, K, Mg, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in safflower plant tissues by 45.47%, 39.33%, 79.28%, 68.21%, 37.06%, 66.67%, 45.62%, 50.38%, 54.37%, 33.33% and 65.87%, respectively, as compared to the control treatments.