Cytogenetics in hybrids of Hordeum jubatum and H. tetraploidum with cultivated barley (H. vulgare L.)

A crossing series between Hordeum vulgare and H. jubatum and H. tetraploidum was carried out. Five genotypes (varieties or lines] of the former species were used as pollen parents together with three accessions of H. jubatum and one accession of H. tetraploidum. There was a large genetic variation in compatibility in crosses among the barley genotypes. Selective chromosome elimination of the whole H. vulgare genome occurred in one hybrid in combination with H. jubatum. Elimination of individual barley chromosomes occurred in three cases. The meiotic pairing in hybrids and haploids agrees well with earlier results, i.e., there is probably no pairing between the H. vulgare chromosomes and those of the wild species. Homoeologous pairing in H. jubatum was generally low. except in two plants, whereas the homoeologous pairing among the H. tetraploidum chromosomes was considerably higher.