Meiotic pairing and alpha-amylase phenotype in a 5B/5R(m) Triticum aestivum - Secale montanum translocation line in common wheat.

A 5BS/5R(m)S translocation chromosome spontaneously recovered from a 'Chinese Spring' - Secale montanum wheat-rye telocentric 5R(m)S addition line has been identified and cytologically studied using C-banding in somatic and meiotic cells. Analysis of the translocated chromosome showed that a terminal segment of the short arm of 5B had been replaced by a short terminal region of chromosome arm 5R(m)S. The translocation led to the deletion of the genetic system promoting pairing located in 5BS, which is slightly compensated for when doses of 5R(m)S are increased, indicating homoeology to wheat chromosome 5BS. The α-amylase phenotype in 5B/5R(m) translocated material was studied and found to be identical to that of ditelocentric line 5BL of 'Chinese Spring'. An effect on the α-amylase activity was detected as a result of the removal of the terminal region of 5BS, perhaps as a consequence of variation in dormancy period duration.