EFFECT OF CADMIUM ON GROWTH AND THE UPTAKE OF CADMIUM AND OTHER ELEMENTS BY DURUM-WHEAT

A solution culture study was conducted to determine the effects of cadmium (Cd) application on the uptake of Cd, potassium (K), zinc (Zn), manganese (Mn), copper (Cu), iron (Fe) and on the growth of seedlings of three wheat (Triticum turgidum L. var Durum) cultivars, Kyle, Nile, and SC84-994. Cadmium application decreased shoot and root biomass, root length, and leaf area. Cadmium application did not produce any differences among cultivars in these growth parameters. There were differential cultivar responses in the uptake of Cd and K but not for Zn, Mn, Cu, and Fe uptake. A solution Cd concentration of 0.1 mu M did not affect the concentration of Cd and K compared to zero Cd but at and above 0.5 mu M Cd, Nile had a higher concentration and contents of Cd and K in root and shoot than SC84-994 and Kyle. Kyle and SC84-994 were not different in any of the elements tested except K concentration in shoot where the order was SC84-994<Kyle<Nile. Cadmium application increased the Cd concentration but decreased the concentration of K, Zn, and Mn in root and shoot, while the Fe and Cu concentrations in shoot and root were not affected. Cultivar differences were observed in the translocation of Cd from root to shoot. In SC84-994 and Kyle, 0.5 mu mole Cd/L decreased the total Cd translocated to shoot, Further addition of Cd did not affect Cd translocation, whereas in Nile, increased Cd concentration in solution did not affect Cd translocation to the shoot. A modified version of Weibull frequency distribution [y = a exp.(b.Cd-c)] was applied to explain the effect of Cd on plant growth parameters and on the uptake of K, Mn, Zn, and Cu in plants.