The polymerase chain reaction (PCR) was used for amplification of the
genome DNA of several genotypes of rye, barley and potato. Oligonucleo
tides, which are flanking sequences of 5S RNA genes were applied as pr
imers. The electrophoretic analysis of the reaction product revealed s
pecific fragments indicative of inter- and itraspecific polymorphism a
mong the genotypes studies.