The effect of nitrate and chloride on the ion transport of rootstock varieties (Fercal, Rupestris du Lot, Georgikon 28) and a scion Kahet was examined with 25 mM Ca(N03)2 or Ca(Cl)2 treatment of rooted one node cuttings grown in 1/10 Hoagland solution. Roots and leaves were analysed for water extractable fraction of anions (NO3", CI", HPO42", S042"; HPLC method) and cations (K +, Ca2+, Mg2+, Na+; AAS method). Varietal differences in anion content of the roots were significant: 5-10 times higher anion levels were measured in Georgikon 28 and Rupestris du Lot than in Kahet and Fercal and this difference was smaller in the leaf blades. CI" was the most mobile anion in the plants reflected by the high CI" level of the roots and leaves in CI" treatments. Two different defending mechanisms can be distinguished on the basis of CI-content of the roots: CI" accumulation (Georgikon 28 and Rupestris du Lot, 2331 and 1845 (imol/g dw. CI" respectively) and CI" exclusion (Kahet and Fercal, 230 and 518 umol/gdw. CI"). A mutual interference of CI" and NO3" ions could be observed. Elevated level (50 mM) of CI" or N03" in the nutrient solution inhibited the transport of the other anion to a large extent. In CI" treatments the NO3" concentration of the roots was decreased to 30-60 % of the NO3" content of the control plants. In the presence of 50 mM NO3", CI" was not found in the roots of Rupestris du Lot and Georgikon 28 and in Kahet and Fercal the low control CI" level was slightly affected. In 25 mM Ca(Cl)2 treatments the intensive CI" transport was accompanied by the increase of the water soluble K+, Ca2+ and Mg2+ concentration in the leaves.