Using sequences of mobile genetic elements in order to mark polymorphic sites in their insertion might be the most effective approach to identify specific features of gene pools of different groups of organisms and control their dynamics, which is especially important in dealing with agricultural species. Sireviruses (Pseudoviridae) one of the oldest LTR-retrotransposons are widespread throughout the plant kingdom. SIRE-1 is one of the largest and most detailed studied retrotransposon. Its analysis showed that insertions of the retroelement (particularly in the genome of maize) have occurred recently. We studied the polymorphism of DNA fragments flanked by LTR-retrotransposon SIRE-1 (IRAP-PCR markers) in the genomes of different taxonomic groups.