Allelic variation in HMW glutenins in Spanish wheat landraces and their relationship with bread quality

The allelic variation of high molecular weight glutenins as principal determinants of bread quality has been analyzed in 165 Spanish wheat (Triticum aestivum ssp. vulgare L.) landraces provided by the Plant Genetic Resources Centre. The identification by standard electrophoresis techniques has been supported by a new PCR screening method, allowing the identification of the 2" glutenin subunit from the Glu-A1 locus in some landraces. The relation of high molecular weight glutenins and bread quality has been evaluated by SDS-sedimentation tests and mixographs. A positive influence on quality has been found for the 2" glutenin subunit from the Glu-A1 locus, pairs 7 + 8 and 13 + 16 from the Glu-B1 locus, and pair 5 + 10 from the Glu-D1 locus. The presence of a wide range of values for quality traits in landraces with the same high molecular weight glutenin composition points to the possible influence of other prolamins such as the low molecular weight glutenins. Their influence on bread quality will be assessed in future studies. A complete description of the high molecular weight glutenin composition and quality values of all the landraces analyzed in this study is provided for use in wheat breeding programs.