Allelic variation of low molecular weight glutenin subunits composition and the revealed genetic diversity in durum wheat (<i>Triticum turgidum</i> L. ssp. <i>durum</i> (Desf))

Abstract

Low molecular weight glutenin subunits (LMW-GS) play an important role in determining the bread-making characteristics of dough in the end-use quality of wheat. In this study, A total of 149 worldwide-originated durum wheat were used to analyze the composition of LMW-GS using MALDI-TOF-MS. Based on the allelic variation of glutenin subunits, the genetic diversity was evaluated for the 149 durum wheat. Five types of alleles were identified at the Glu-A3 locus with Glu-A3e, Glu-A3a/c, Glu-A3f, Glu-A3d and Glu-A3b accounting for 43.0%, 16.1%, 12.8%, 10.1% and 7.4 % of the accessions, respectively. Five types of alleles were identified at the Glu-B3 locus: Glu-B3d (60.4%), Glu-B3b (6.0%), Glu-B3c (6.0%), Glu-B3h (2.7%) and Glu-B3f (0.7%). Two novel alleles encoding abnormal subunits 40500 Da and 41260 Da were identified at the Glu-A3 and Glu-B3 loci, respectively. Further studies are needed to match these novel alleles to previously discovered novel alleles. Moreover, the genetic diversity analysis indicated that great genetic variation existed in durum wheat among encoding loci of glutenin subunits, released periods of varieties and different geographical origins. The results provide more important information of potential germplasm for the improvement of durum wheat and common wheat.

Assessment of the Glutenin Subunits Diversity in a Durum Wheat (T. turgidum ssp. durum) Collection from Morocco

“…Recently, recombination has been reported in some of the LMW glutenin Glu-3 loci [53], which could also affect allele nomenclature. At the Glu-A3 locus, alleles Glu-A3a and Glu-A3e were the most frequent, in accordance with other studies that also reported the predominance of the Glu-A3a [19,22,27,39,45] and Glu-A3e [54] alleles within different sets of durum wheat accessions. According to previous studies, the Glu-A3a and Glu-A3e alleles have been associated with stronger and weaker gluten, respectively.…”

Application of Marker-Assisted Selection in Wheat Quality Breeding Program

“…Previous studies confirmed the relationship of the allelic diversity of storage proteins loci with quality indices and economical traits [27,37]; for example, Glu-D1 (5 + 10) with Glu-B3i and Glu-A3c allele are recognized for their positive effects on end-use quality, or Glu-B3g, Glu-A3d, Glu-A3b, Glu-B3b, Glu-D3a, and Glu-D3b alleles extremely contribute to the gluten complex, enhance the dough strength, and finally strongly affect the bread-making quality [26,38]. Due to the close association between the allelic variants and dough quality in bread wheat, the allelic diversity of LMW-GS has thus been widely recognized in wheat [39][40][41][42]. It is shown that at Glu-A3 locus, the Glu-A3d and Glu-A3b allele improved bread-making quality, while Glu-A3e contributes to a bad characteristic of dough [43].…”