Molecular characterization of several Wx alleles in durum wheat

The Wx gene, which encodes waxy proteins, is the sole gene responsible for amylose synthesis in the wheat seed endosperm. In this study, we characterized, at the molecular level, several Wx alleles in durum wheat (Triticum turgidum L. ssp. durum Desf.) that had previously been catalogued at the protein level. Our data show a misclassification of the alleles in both Wx genes: Wx-A1 alleles from Blanqueta (Wx-A1a) and Astrodur (Wx-A1b) have been reclassified as Wx-A1a and Wx-A1h, respectively. A sequence comparison of the Wx-B1e allele shows that there were up to five different alleles under this denomination, which confirms that the protein analysis by SDS-PAGE separation needs to be combined with the PCR amplification-sequencing analysis in order to obtain a correct classification of the alleles, which will facilitate their use in wheat quality improvement.