Giemsa C-banding and the evolution of wheat.

The somatic chromosomes of common wheat, Triticum aestivum L. (2n = 6x = 42), and those of two of its diploid progenitors and T. speltoides, have been individually identified by a Giemsa staining technique. In wheat, telocentric chromosomes were used to aid the recognition of individual chromosomes, and an ideogram has been constructed depicting the C-band positions. There is no similarity in the C-banding of chromosomes within a homoeologous group, with the possible exception of group 5. Comparisons of the C-banding of the diploid species T. monococcum, T. speltoides, and T. tauschii with that of the A, B, and D genomes, respectively, in hexaploid wheat corroborate that T. speltoides could not be the donor of the B genome to wheat and that T. monococcum and T. tauschii are the probable donors of the A and D genomes, respectively.