Assessment of resistance of wheat genotypes (T. aestivum and T. durum) to copper toxicity

Copper (Cu) availability to plants depends on a large number of factors and their interactive relationships. Especially, localized excess soil Cu is often a great risk for plant growth on the agricultural lands. Development of resistant varieties to Cu toxicity is a high priority on these regions, where the soils have high levels of Cu. Thus, this study aimed to assess the resistance of wheat genotypes to Cu toxicity using the agronomic and physiologic parameters. For this aim, a pot experiment, based on a completely randomized design with three replications, was conducted using the soil of calcareous usthochrepts. In the study, twenty different wheat genotypes of T. aestivum and T. durum were used. Copper fertilizer at the levels of 0 (-Cu) and 20 mg Cu kg(-1) (+Cu) as CuSO4 center dot 5H(2)O was applied to the pots. After harvest, plant dry matter yield was recorded, and total Cu concentrations in tops of wheat plants were determined. The results indicated the existence of a large genotypic variation among wheat genotypes to their physiologic and agronomic susceptibility to Cu toxicity. Resistance of bread wheat cultivars of T. aestivum to Cu toxicity were higher than that of wheat cultivars of T. durum under the Cu toxicity condition. Thus, evaluation of assessment of new wheat cultivars to Cu toxicity could also be used in breeding programs in order to develop more Cu-tolerant cultivars.