Abstract

The presence of heavy metals is one of the most important environmental stresses. Uranium is the heaviest trace element in nature. To investigate the effects of uranium on the germination and growth of sunflower and sorghum seeds, laboratory testing was conducted in a completely randomized design with four replications. Various concentrations of uranium were 0, 50, 100, 200, 400 and 800 ppm. The results showed that levels of uranium on all traits had a significant effect (1%). The results of analysis of variance for all traits except germination rate and germination percentage showed that sunflower and sorghum were significant at 1%. Seedling length, shoot length and seedling vigour index had the largest decrease with increasing concentrations of uranium. The comparison means showed that the sunflower was more tolerable on various levels of uranium especially at higher levels. A significant correlation was observed between germination percentage and rate of germination. Also a significant correlation was observed between vigour and seedling.