Chromosome instability in intergeneric hybrids of Triticum aestivum×tritordeum (amphiploid Hordeum chilense×Triticum turgidum) with high dosage of Ph1 gene of wheat

In somatic cells of intergencric hybrids Truicum uestirum (mono-isosomic 5BL, 2n=6x=4f)x trinordum 12n = 6x = 42, amphiploid Hordeum clulense x Triticum turgidnm)it was observed that high dosage of the long arm of 5B induced chromosome instability in hybrids 2n=42, in hybrids 2n=41 with only one dose of 5BL from the normal 5B genome of the teteaploed wheat, all cells have consistently 2n=41 chromosomes and no rmal 5B genome of the tetraploid wheat all cells have consistently 2n=41 plant differenttation in plants with 2n=42 which carry three doses of 5BL (one isochromosome 5BL and one 5B chromosome)most of the metaphase cells had 2n=42 chromosomes. However other cells in a reasonable frequency varying from 19% to 40% carried from 2n=6 to 2n=44. and showed marked desturbances in all phases of the cell cycle leading to final failure in plant development. It is suggested that the Ph1 geng of wheat. Located on 5BL regulates chromosome stability in the somatic cells of those hybrids.