ANALYSIS OF THE GENOTYPIC VARIATION IN RADIOCESIUM UPTAKE FROM SOIL

Young spinach (Spinacia oleracea L., cv. Subito) and wheat (Triticum a estivum, cv. Tonic) plants were hydroponically grown in eight differen t nutrient solutions containing Cs-137. Ca, Mg, K and NH4 concentratio ns were varied whilst anion concentrations were equal in all solutions . The large differences in potassium content between spinach and wheat were not reflected in similar differences in Cs-137 content at any nu tritive treatment. Both crops were also grown in a potted podzolic soi l contaminated with radiocaesium. This experiment was conducted in a p hytotron at two climatic conditions ('summer' and 'winter') which diff ered in day length and light intensity. Wheat plants had higher Cs-137 levels than spinach at both conditions. The Cs-137 levels furthermore decreased during development. The Cs-137 plant/soil solution concentr ation ratio was lower at the 'summer' than at the 'winter' conditions.