Incomplete preferential pairing in a tetraploid Secale hybrid carrying translocations: Multivalent configuration frequencies and marker segregation

Meiotic configurations and segregation were studied in tetraploid hybrids (4n=28) between Secale cereale (2n=14) carrying a reciprocal translocation between chromosomes II and VI and a derivative of Secale montanum (2n=14), naturally differing from S.cereale in a translocation involving chromosomes I, III and V. Multivalent frequencies of the translocation complexes were reduced compared to expected but of still appreciable magnitude, which was ascribed to incomplete preferential pairing. Marker segregation (one of the S. cereale translocation chromosomes) also suggested partial preferential pairing.