Allelic variation of HMW glutenin subunits of Ethiopian bread wheat cultivars and their quality

Abstract

High molecular weight glutenins are often effective in identifying wheat (Triticum aestivum) genotypes with good baking quality. The high molecular weight glutenin subunit composition of Ethiopian cultivars and advanced lines was investigated to determine their influence on quality. Three alleles at Glu-A1, five at Glu-B1 and two at Glu-D1 and eleven different banding patterns were identified. Few cultivars had biotypes at Glu-A1 and Glu-D1 loci. There were highly significant differences between genotypes and banding patterns for the SDS-sedimentation test, mixograph development time, alveograph strength and loaf volume; but not for protein content. The frequency of subunits 5+10 among genotypes was 73%. The accumulation of high scoring alleles in our germplasm was without deliberate selection pressure towards high Glu-1 scoring alleles during breeding. Introductions from CIMMYT are widely used and such materials might have gone through selection and accumulation of such alleles at CIMMYT. Most of the studied materials had the required subunits of high quality scores and better values of the quality traits than originally thought. Therefore, the concern about poor baking quality is unlikely to be due to Glu-1 allelic variations alone.

Key Words: Allelic variation, grain quality, HMW glutenins