Abstract

Baking quality is a key factor in the development of improved wheat (Triticum aestivum L.) cultivars and it is associated with a specific protein fraction known as High Molecular Weight (HMW) glutenins, although there are other proteins involved in baking quality. Current selection of wheat germplasm with improved baking quality is based on gluten and dough analyses, or the identification of HMW glutenin alleles using electrophoretic procedures. This report presents the deployment of an allele-specific Polymerase Chain Reaction (PCR) system to identify the presence of the gene encoding the Glu-D1 HMWx5 glutenin, associated with good baking quality. Primers targeting part of its promoter and its 5? extreme were used to differentiate it from its allele Glu-D1 HMWx2. A 450 pairs of bases (pb) band was amplified in genotypes carrying the allele HMWx5, a size consistent with that expected from GenBank sequence data, whereas no amplification was observed in genotypes carrying the HMWx2 allele. The system was validated on a wide range of unrelated Chilean genotypes and allowed the rapid and unequivocal identification of genotypes possessing the HMWx5 allele with high throughput. The development of this and other systems will allow the development of more effective and focused breeding approaches in wheat.