Background: Plants differ in the methods used to acquire nutrients from environments with low nutrient availability, and may change the morphology of their root architecture to be able to take up nutrients. Results: In the present study rye response to stress caused by high and low nitrogen-potassium treatments in mature embryos cultures was described within a population consisting of one hundred and thirty eight recombinant inbred lines of rye. Characterization of the response of recombinant inbred lines (RILs) to nutrient stress was presented as the results of analyses of morphological traits, and physiological and biochemical parameters of the seedlings grown in both treatments. A wide range of variability of individual RILs to induced stress was observed in the population of recombinant inbred lines, and was presented as the difference between the means of each of the analysed traits described at high- and low-nitrogen-potassium levels. Lines were grouped using Ward's agglomerative method on the basis of differences in coleoptyle length, with the longest root length and root number used as variables. Conclusions: Recombinant inbred lines at low nitrogen-potassium treatment developed: longer, shorter, or roots of similar length in comparison with the high nitrogen-potassium treatment. Discriminant function analysis showed that the discriminant variable able to clearly differentiate recombinant inbred lines in terms of their response to nutrient stress was the trait of the longest root length.