Growth and phytoremediation capacity of sunflower grown on soil contaminated with cadmium

The purpose of this study was to characterize sunflower (Helianthus annuus L. cv. Oleko) regarding its potential to be included in the phytoremediation programs for the contaminated areas of national interest of southern Italy. Therefore, Cd uptake, distribution and dose-response patterns were studied in plants subject to six levels of Cd contamination (from 2.5 up to 15 mg kg-1 of soil). No large differences were found on growth and physiological parameters as effect of Cd contamination. Regardless of treatments, Cd accumulated mainly in roots than in shoots, even at low concentration in soil. Moreover, Cd accumulation in roots and leaves progressively increased by increasing Cd in soil, while in stem and flower bud it remained almost constant above of 5 mg kg-1 of Cd in soil. The storage of heavy metal in roots and older leaves could be considered as a strategy of sunflower to avoid toxic accumulation in growing tissues.