Identification of SNPs and development of allelic specific PCR markers for high molecular weight glutenin subunit Dtx1.5 from Aegilops tauschii through sequence characterization

The high molecular weight (HMW) glutenin subunits Dtx1.5+Dty10 from Aegilops tauschii are a novel pair of subunits not detected previously in common wheat (Triticum aestivum). The partial DNA sequences of the x-type HMW glutenin alleles from A. tauschii and synthetic hexaploid wheat samples with different HMW glutenin subunits were charcterised. Five samples were found to contain the HMW glutenin subunit Dtx1.5 that may affect bread-making quality. Polymorphisms of the DNA sequences were detected among alleles encoding different HMW glutenin subunits and within an allele encoding the same HMW glutenin subunit, such as the Dtx1.5 subunit. Three single nucleotide polymorphisms (SNPs) that can distinguish the Dxt1.5 from Dtx2, Dtx5, Dx2 and Dx5 alleles were identified. Allelic specific (AS)-PCR primers were developed based the SNPs located at the non-repetitive N-terminal of the HMW glutenin subunits. The AS-PCR primers can accurately identify accessions containing the Dtx1.5 subunit from those containing other studied subunits by PCR analysis, suggesting the usefulness of AS-PCR for identifying different HMW glutenin subunits of A. tauschii and synthetic hexaploid wheat. The AS-PCR primers developed based on SNPs in this study are valuable in wheat breeding for effective selection of special HMW glutenin subunits.