Morphological and cytological characteristics of some wheat x barley hybrids.

As initial step in the transfer of dwarf bunt resistance from barley into wheat, the two cereal crops were hybridized. Using the wheat cultivars 'Fukuhokomugi' and 'Chinese Spring' (AABBDD genomes) as female parents and barley cultivar 'Luther' (II genome) as male, we synthesized 9 euploid hybrids (2n = 4x = 28; ABDI genomes). The hybrids were vigorous, but highly sterile. Meiotic analyses of seven hybrids showed considerable variation in chromosome pairing. Of the hybrids involving 'Fukuhokomugi' 3 had high pairing with a mean of 5.08-6.72 chiasmata per cell, while others had 2.16-3.52 chiasmata per cell. As many as 12 bivalents in some pollen mother cells would suggest at least some pairing between wheat and barley chromosomes. This level of homoeologous pairing, coupled with some, albeit low, female fertility of the F1 hybrids, could offer an opportunity for intergeneric gene transfers from barley into wheat and vice versa.