Allelic variations of functional markers for high molecular weight glutenin genes in Indian wheat (Triticum aestivum L.) cultivars and their correlation with bread loaf volume

Abstract

Glutenins, the polymeric proteins are composed of high molecular weight (HMW) and low molecular weight (LMW) glutenin subunits. High molecular weight glutenin subunit (HMW-GS) plays a key role in determining bread making quality. The HMW-GS encoded by Glu-1 loci (GluA1, GluB1 and GluD1) are highly polymorphic. Thus it is very important to identify the alleles at Glu-1 loci for all three genomes for wheat quality improvement. In the present study 53 Indian wheat genotypes were evaluated for HMW-GS composition using PCR-based DNA markers. In total, two alleles (Ax2*, Ax1 or Axnull) at Glu-A1, four allele/allelic pairs (Bx7, Bx7 + By8, Bx7 + By9, Bx17 + By18) at Glu-B1 and two allelic pairs (Dx2 + Dy12 and Dx5 + Dy10) at Glu-D1 were identified using diagnostic DNA markers. Allele or allelic pair Ax2* (62.3 %) at Glu-A1, Bx7 + By8 (64 %) at Glu-B1 and Dx2 + Dy12 (58.5 %) at Glu-D1 were present most frequently in wheat genotypes taken for study. Moreover, the allelic combination Ax2*, Bx17 + By18 and Dx5 + Dy10 exhibited highest bread loaf volume in comparison to other allelic combinations studied. The set of markers used here thus represents a useful alternative for screening of HMW-glutenin allele (s) for improvement of bread making quality in Indian wheat genotypes.