High molecular weight glutenin subunit composition (Triticum aestivum L.)

Abstract

The suitability of a wheat (Triticum aestivum L.) cultivar for different end uses, viz., bread, chapathi, biscuit, noodle and pasta products is determined to a large extent by its seed protein composition [1]. Glutenin proteins of wheat endosperm form polymeric aggregates that vary widely in molecular size and that confer unique viscoelastic properties on wheat flour dough. The high molecular weight subunits of glutenin are of special significance because, despite constituting only about 10% of the total flour protein, they make a profound contribution to dough strength [2]. These subunits are encoded by genes at the Glu-A1, Glu-B1, and Glu-D1 loci on the long arm of homoeologuous chromosomes 1A, 1Band 10 respectively. The subunits are highly polymorphic and a number of alleles have been identified at each of the homoeo loci [3]. These alleles have different effects on dough viscoelastic properties. Hence, these subunits are useful not only for the identification of wheat cultivars, but can also be used by breeders in choosing parental lines and selecting progenies with superior gluten quality. Although India is the second largest producer of wheat in the world, limited information is available on the allelic variation for these proteins among the Indian wheat cultivars [4].