Novel allelic variants encoded at the Glu-D3 locus in bread wheat

Low-molecular weight glutenin subunits (LWM-GS) are important components of wheat (Triticum aestivum L.) gluten, with important effects on end-use quality. The LMW-GS are encoded at Glu-3 loci (Glu-A3, Glu-B3 and Glu-D3, on the short arms of chromosomes 1A, 1B and 1D), each of which exhibits extensive allelic variation. Each locus encodes numerous LMW-GS, some of which have similar electrophoretic mobilities, making it difficult to distinguish among Glu-3 loci. Alleles of the Glu-D3 locus of bread wheat are considered the most problematic to assign. To date, six Glu-D3 alleles, designated a, b, c, d, e and f, have been reported. We report five previously undescribed alleles (g, h, i, j and k), and describe a method for characterizing them using a combination of SDS-PAGE and multiplexed PCR-based DNA markers. This method could be used for accurate identification of Glu-D3 alleles, permitting the estimation of the effects of these alleles on end-use quality and the selection of desirable alleles and allelic combinations in wheat breeding.