Allele-specific PCR Markers for Distinguishing High Molecular Weight Glutenin Subunit Dtx5 of Aegilops tauschii from Dx5 of Common Wheat

High molecular weight (HMW) glutenin, one of the important storage proteins of wheat, mainly confers end-use quality of wheat grain. Among the loci of HMW-GS, the locus D1 determines the breaking quality of bread wheat dough mostly. Synthetic hexaploid wheat (SHW) inherits vast genetic diversity in the D genome of Aegilops tauschii and has gradually been used as a bridge-tool for wheat improvement. Therefore, more and more HMW-GS subunit types of Ae. tauschii have been introgressed into the common wheat with irresistible application of SHW in wheat breeding. However, the traditional SDS-PAGE couldn’t distinguish Dtx5 of Ae. tauschii from Dx5 of common wheat. In this study, we developed two AS-PCR markers based on three SNPs in the HMW-GS D1 sequences of Ae. tauschii and common wheat. The sharp and stable fragments amplified by designed AS-PCR primers indicated their availability and convenience in Dtx5 and Dx5 identification. And Dx5 of common wheat obtained the amplified fragments by AS-PCR primers, while no fragment was amplified for Dtx5 of Ae. tauschii. And the amplified results were consistent in both pairs of AS-PCR primers. Moreover, Dtx5 is more highly homologous with Dx2 than Dx5 from their protein sequences.