Allelic variation at the Gli-A1m, Gli-A2m and Glu-A1m loci and breadmaking quality in diploid wheat Triticum monococcum

Abstract

Fifty-six accessions of Triticum monococcum and one accession each of T. beoticum and T. sinskajae were analysed for their storage protein compositions and breadmaking quality as determined by the SDS-sedimentation test. In total 30 different alleles at the Glu-A1m locus coding for high-molecular-weight glutenin subunits (HMW-GS), 25 alleles at the Gli-A1m locus coding for ω- and γ-gliadins and 45 alleles at the Gli-A2m locus controlling the synthesis of α/β-gliadins were detected. Most accessions contained one x-type and one y-type HMW-GS and two genotypes were null for both types of subunits. Two polypeptides within the mobility range of HMW-GS in SDS-PAGE were shown to be ω-type gliadins encoded by genes on the short arm of chromosome 1 A. T. sinskajae and several ‘monococcum’ accessions were shown to share the same alleles at Gli-A1m, Gli-A2m and Glu-A1m, confirming sinskajae as a subspecies of T. monococcum. The SDS-sedimentation volumes of most accessions were very low (11–35 ml), a few accessions showing mean sedimentation volumes as high as 90–93 ml. Through the comparison between biotypes occurring in some accessions of ‘monococcum’, good bread-making quality was found to be associated with the presence of alleles y, c and i at the Gli-A1m locus. All accessions were resistant to leaf rust and rich in protein (≥ 16·5%), and most of them showed resistance to powdery mildew. © 1995, Cambridge University Press. All rights reserved.