Crossability and chromosome pairing in some interspecific Triticum hybrids

Abstract

Different species of Triticum (sensu stricto) were crossed with T. ovatum, T. triunciale, T. crassurn. and T. tauschii (belonging to the previously recognized genus Aegilops). Hybrid plants were obtained in 7 interspecific combinations. The seed set was rather good in most attempts when a species from Triticum sp. (sensu stricto) was used as male parent, but low when used as female. All the hybrids were sterile; pollen stainability was about 1 % and no seeds were set. The chromosome pairing was low with few bivalents, mainly as rods. Multivalents were rare. The chiasma frequency ranged from 7.64 chiasmataiceil (T. triunciale x T. aestivum ssp. aestivum) to 0.76 chiasmata/cell in T. aestivum ssp. aestivurn x T. ovatum. T. triunciule x T. aestivum ssp. spelta was backcrossed to bread wheat. Most plants in the first three backcross generations were strongly hyperploid. The plants were male sterile, probably due to cytoplasmic interactions.