Comparison of uptake and distribution of cadmium in different cultivars of bread and durum wheat

The intent of this study was to investigate whether high levels of cadmium (Cd) in the grains of high Cd-accumulating cultivars is caused by a high Cd uptake in the roots, a high translocation of Cd from roots to shoot, or a redistribution of Cd between the shoot and the grains. High and low accumulators, with respect to the grain accumulation of Cd, of spring and winter bread wheat (Triticum aestivum L.) and of durum wheat (T. durum Desf.) were selected from field studies. The selected cultivars were grown in nutrient solution containing 0.5 mM Cd in a climate chamber for (i) 19 d and (ii) until maturity. The concentration of Cd in roots, shoot, flag leaves, grains, and grain coats was measured by atomic absorption. The results indicated that there are differences among the cultivars in the ability to accumulate Cd in grains. The biggest differences were found among the durum wheat cultivars. Different Cd accumulation in grains was related to variations in the translocation from root to shoot and to the Cd concentration in shoot, flag leaf, and grain coats, but not to the uptake of Cd by roots.