Translocations and modifications of chromosomes in triticale � wheat hybrids

Abstract

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.

Complete identification of common wheat chromosomes by means of the C-banding technique.

“…Also, sometimes, the centromere position looked stained in most of the chromosomes, but this type of staining was not regarded as a specific band; because it did not appear regularly and because it seemed to be of the same nature as the shaded fringe of the chromosomes, which was sometimes observed. The above-mentioned facts might explain the partial difference in banding pattern of `Chinese Spring' between the Cbanded karyotype in this study and the ideograms of the C-banded karyotypes by Gill and Kimber (1974) and by Lukaszewski and Gustafson (1983).…”

Structural differentiation of chromosomes between Triticum dicoccoides Koern. and T. araraticum Jakubz., showing high meiotic pairing homology.

“…Symp.) reported in the other Emmer wheats and T. aestivum (AABBDD) (Gerlach, 1977;Iordansky et al, 1978;Van Niekerk and Pienaar, 1983;Lukaszewski and Gustafson, 1983;Endo and Gill, 1984). T. dicoccoides KU8821A and KU8821 also showed eight banded chromosomes, whose banding patterns were similar to those of the Bgenome chromosomes and chromosome 4?…”

Tools and methodologies for cytogenetic studies of plant chromosomes

“…Except for the work of Simeone et al (1988), the efforts of other investigators (Zurabishibili et al, 1978;Seal, 1982;Lukaszewski and Gustafson, 1983) to identify the A and B genomes of T. turgidum on the basis of their C banding patterns have been inconsistent. Simeone et al (1988) reported C banding patterns for chromosomes of T. turgidum that were equivalent to those of their homologues in the A and B genomes of T. aestivum and therefore permitted their unequivocal identifi cation.…”