It was established that the genome of Rumex acetosa L. callus tissues undergoes significant changes during cultivation in vitro, even after the first passage. After the second and the following passages aneuploidies in the caryotype appear. Introduction of antioxidants into the culture media complex slows down the somaclonal variation as a change in chromosome structure after the second passage. The most important way to reduce somaclonal variation remains compliance with the methodological recommendations, as well as the use of direct regeneration.

Key words: somaclonal variation, callus tissue, biotechnology, karyotype, aneuploidy.