Translocations and modifications of chromosomes in triticale × wheat hybrids.

Several generations of four triticale × wheat populations were cytologically analyzed on a plant-by-plant basis using C-banding. Among 785 karyotyped plants, 195 wheat/rye and 64 rye/rye translocated chromosomes were found, as well as 15 rye chromosomes that were modified by deletion or amplification of telomeric heterochromatin. Most of the translocations involved complete chromosome arms; only a few involved smaller segments of chromosomes. Out of 39 identified wheat/rye translocations, 10 occurred between homoeologous and 29 between non-homoelogous chromosomes, five involved A-genome chromosomes, six B-genome chromosomes and the remaining 28 involved D-genome chromosomes. The study indicated that wheat/rye translocations can be produced in sufficient numbers to allow the use of this method for the introduction of alien variation into wheat research programs. Changes in the C-banding technique used are discussed in detail.