IMPACT OF CADMIUM TOXICITY ON LEAF AREA AND STOMATAL CHARACTERISTICS IN FABA BEAN

Abstract

Although changes in stomatal response to elevated doses of cadmium has already been observed in several plants, few studies have focused on this phenomenon in more detail. The effects of different doses of cadmium Cd²⁺ (50 and 100 mg.kg^-1 soil) on leaf area and stomatal characteristics (number of stomata, number of epidermal cells, stomatal index and size of stomata) of faba bean (Vicia faba L. cultivar AÅ¡tar) were studied after 15 days of heavy metal treatment. No visual changes on adaxial or abaxial side of leaves of the tested variety of faba bean were found. The leaf area was higher by 14.15 % at lower and by 12.23 % at the higher doses of Cd. The tested doses of Cd did not lead to a change in the number of stomata. The number of epidermal cells was increased on adaxial side by 4.98 % at dose Cd50. Stomatal index was decreased due to the effect of higher dose of cadmium by 11.38 % on adaxial side of leaves. In stomatal widths, decrease by 2.04 % (adaxial side) and 2.26 % (abaxial side) was observed at higher doses of Cd. In stomatal length decrease by 1.85 % was observed at higher dose of Cd on adaxial and decrease by 3.89 % (Cd50) and 4.63 % (Cd100) on abaxial side of leaves respectively. The variations of response could be signals of tolerance or adaptive mechanisms of the leaves of tested bean cultivar under the used concentrations of cadmium.