GENOTYPE SPECIFICITY OF WINTER WHEAT (TRITICUM AESTIVUM L.) IN CADMIUM, ZINC AND IRON ACCUMULATION IN GRAIN

This study examined the uptake, translocation, distribution and accumulation of Cd, Zn and Fe and the interaction of these elements in winter wheat. The objectives were: (1) to characterise specificity among winter wheat genotypes in terms of accumulation of Cd, Zn and Fe in various organs and identify genotypes combining low accumulation of Cd with high accumulation of Zn and/or Fe, (2) to determine genetic specificity of winter wheat genotypes in terms of translocation of Cd, Zn and Fe from the vegetative parts to the grain, and (3) elucidate an effect of soil cadmium contamination on the distribution and accumulation of Cd, Zn and Fe in various organs of wheat. In the 2007/2008 vegetation season, 52 winter wheat varieties (34 Croatian, 7 Austrian, 5 Hungarian, 3 French and one variety of Russian, Italian and German descent) were investigated. The pots were arranged, according to a completely randomized design with two levels of soil Cd contamination (0 and 20 mg kg-1 soil) in four replicates. In the vegetation season of 2008/2009 the experiment was set up to a completely randomized block design with 10 varieties of wheat and three levels of soil Cd contamination (0, 2 and 5 mg kg-1 soil) in four replicates. The concentration of Cd, Zn and Fe in the solution of plant samples was determined by ICP-OES. The concentration of Cd, Zn and Fe was determined at the flowering stage in the root, stem,leaves, flag leaf and spike and in a full maturity in the straw, leaves, glumes and grain. Collected data were statistically analyzed with SAS software 9.1.3. Analysis of variance identified a statistically significant difference in the concentrations of Cd, Zn and Fe in vegetative parts and grain between the tested wheat varieties at all levels of soil Cd contamination. It was also found that the soil Cd contamination had a significant effect on the accumulation of Cd in grain while the accumulation of Zn and Fe in the grain hasn’t been influenced by soil Cd contamination. The tested genotypes differed significantly in the Cd, Zn and Fe plant uptake factor as well as in the coefficient of translocation from roots to stems and from roots to the flag leaf. According to correlation coefficient between the concentrations of Cd, Zn and Fe in the grain, the tested cultivars were divided into six groups which differ in the interrelation of these elements. Obtained results may serve as a starting point for investigation of the mechanisms of uptake, translocation and accumulation of Cd, Zn and Fe in winter wheat as well as for the selection of genotypes with increased concentrations of Zn and Fe and decreased Cd concentration in the grain.