EN
The aim of the study was an early detection of somaclonal variation (SV) which could occur within the micropropagated plant material. Shoot cultures of the Polish cultivars were used. Five cultivars derived from breeder A and four from breeder B. They were propagated in vitro for one or two years. The molecular markers (inter-simple sequence repeat, ISSR) were utilized for analysis of putative DNA polymorphism between standard plants (propagated traditionally) belonging to tested cultivars and somaclonal variants derived from them. Within the nine studied genotypes, for five of them, the ISSR analysis performed with ten primers did not reveal polymorphism between standard and micropropagated plants. The analysis of the other four cultivars, all derived from breeder B, showed that some of the plants, micropropagated either for one or two years, differed slightly from standard. Basing on ISSR data, the UPGMA dendrogram showing genetic similarity of the analysed plants was generated and clusters grouping cultivars, their standards and micropropagated plants were noted.