Concentration of uranium in root-crops, bulbous and tuberous plants

Abstract

Continuing our investigations with regard to the uptake and concentration of U in cultivated plants depending on their biological properties, we wanted to investigate the uptake, distribution and concentration of U in several kinds of root - crops, bulbous and tuberous plants grown on barren soil in natural conditions. The results that were obtained in our earlier investigations showed that the concentration of U in the root was higher than in the above-ground parts of the investigated plant species. However, there was place for justified doubt that in spite of a process of thorough washing, we had not removed all U from the outer covering of the root. As the surface layer is easily removed from the thickened roots, bulbs and tubers, these plants were used as model plants for eliminating such doubts. The following plant species were used: carrot (Daucus carota L., cv Nantes), onion (Allium cepa L., cv Kupusinski jabučar), potato (Solarium tuberosum L., cv Desire), radish (Ranphanus sativus var.maior cv. Smederevska Palanka), red beet (Beta vulgaris L., var. escuienta cv. Smederevska Palanka) and sugarbeet (Beta vulgaris L., cv. Dana). They were grown on the barren soil deposit of the Gabrovnica - Kalna U mine located in Serbia. The highest concentration of U in the above ground part were found in potato, then red beet, sugarbeet, carrot, radish and as last, onion. At the same time the results for the thickened roots, bulbs and tubers showed that red beet had the highest concentration, then came radish, carrot, sugarbeet, potato and onion. All plant species showed higher concentration of U in the peel of the surface root layer, and it differed among the plant species. Plant species differed in the level of concentration of U in the remainder of the root as well as in leaves. The concentration of U in leaves for all plant species was higher than the concentration of U in the remainder of the root. All data point out that the uptake and concentration of U is specific for particular plant species. It should be kept in mind that investigated plant organs are used for food and fodder, which adds to the significance of these investigations.