Detection of HMW glutenin subunit variations among 205 cultivated emmer accessions (Triticum turgidum ssp dicoccum)

The high molecular weight glutenin subunits (HMW-GS) encoded by Glu-1 loci among 205 accessions of cultivated emmer wheat (Triticum turgidum ssp. dicoccum Schrank) collected from different regions of Europe and China were separated and characterized by SDS-PAGE in combination with two-dimensional gel electrophoresis (A-PAGE x SDS-PAGE) and acidic capillary electrophoresis. High genetic polymorphisms in HMW-GS compositions were found. A total of 40 alleles (6 for Glu-A1 and 34 for Glu-B1) and 62 subunit combinations (genotypes) were detected, some of which were not previously described. At Glu-A1 locus, two novel alleles, designated Glu-A1x coding for the subunit 1A x 1.1 and Glu-A1y coding for the subunit 1A x 2.1' were found while seven new subunits (1B x 17*, 1B x 6', 1B x 13', 1B x 20*, 1By9*, 1By14.1 and 1By8.1) and 20 novel alleles at Glu-B1 locus were detected. In particular, some additional protein components were detected, which probably were 1Ay subunits encoded by Glu-A1 locus. The introduction of both Ax and Ay subunits from tetraploid wheats into hexaploid wheats may increase the genetic variability of gluten genes and consequently improve flour technological properties.