Induction of Chromosomal Structural Changes by a Chromosome of Aegilops cylindrica L. in Common Wheat

Chromosomal structural changes-deletions and translocations-occurred in almost half the progeny of a monosomic addition line of common wheat, Triticum aestivum (2n = 42, AABBDD), which had a chromosome from Aegilops cylindrica (2n = 28, CCDD). Most of the progeny with chromosomal structural changes lacked the A. cylindrica chromosome. Chromosome breaks were observed in various regions of all the wheat chromosomes and the A. cylindrica chromosome. Chromosome aberrations occurred far less frequently both in the self-progeny of the disomic addition plants and in the F1 monosomic addition plants derived from reciprocal crosses with normal common wheat. These findings suggest that when the A. cylindrica chromosome was in the sporophytes, chromosome breakage was likely to occur in the gametophytes that lacked it but that the gametophytes were still functional, resulting in the production of offspring with chromosomal structural changes.