Growth of Four Varieties of Barley ( Hordeum vulgare L.) in Soils Contaminated with Heavy Metals and Their Effects on Some Physiological Traits

Abstract

To evaluate the effect of zinc (Zn), cadmium (Cd), and chromium (Cr) on growth and selected physiological traits in barley, a greenhouse trial was performed using four barley varieties that were exposed to different concentration of these metals. The parameters quantified were growth, chlorophyll content, and chlorophyll fluorescence during three phenological stages: flag leaf, anthesis, and grain filling. The metal concentrations in both the plant and soil were also quantified. We determined that the varieties studied were more tolerant to Zn and Cd than to Cr. Treatment with Zn did not negatively affect growth, and only high concentrations of Cd decreased growth by approximately 4% to 8%. Plants treated with the highest Cr concentration stopped growing at the flag leaf stage. The amount of metal that accumulated in the plant increased with increasing metal concentration, and the highest amount of accumulated metal was recorded in the root and shoot. Both the plant height and dry weight were higher in the CB502 variety plants, followed by the Reinette, Pedrezuela, and Plaisant varieties. The same trend was observed for the chlorophyll content and fluorescence, with a significant correlation between the growth parameters and chlorophyll content (p < 0.001). Thus, we determined that barley has variability in the studied traits.