Sequences derived from a rye gamma secalin gene were used as primers in polymerase chain reactions using DNA obtained from a series of wheat and triticale genetic stocks. A 473-bp fragment, the predicted size based on the distance between the selected primers, was found only in rye, triticales, and wheat lines carrying rye chromosome 2RS. Use of triticale lines with various wheat chromosome substitutions confirmed the chromosomal origin of the rye-specific marker. The presence of the 473-bp PCR product was always associated with the production of 75K secalins in grain samples. Thus, the primer sequences, and the clone of origin (pSC503), were both derived from the SEC-2 locus of rye chromosome 2RS.Key words: wheat (Triticum aestivum), rye (Secale cereale), chromosomal translocations, chromosomal substitutions, DNA polymerase chain reaction, sequence-specific primers.