Variation for glutenin and waxy alleles in the US hard winter wheat germplasm

Abstract

We conducted a survey of high- and low-molecular-weight glutenin subunits (HMW-GS and LMW-GS, respectively) and waxy ( Wx) allele composition in 111 winter wheat cultivars and advanced lines developed in the US Hard Winter Wheat Region since 1991. At the HMW-GS Glu-A1 locus, 76.1% of entries had allele b (encoding subunit 2*), 21.2% carried allele a (subunit 1), and 2.7% had allele c (null). Glu-B1 alleles were c (subunits 7+9; 47.7% of entries), b (subunits 7+8; 33.3%), e (subunits 20x+20y; 7.7%), i (subunits 17+18; 6.3%), and w (subunits 6*+8*; 5%). At Glu-D1, 80.6% of the entries carried allele d (subunits 5+10), 11.3% had allele a (subunits 2+12), 7.2% carried allele b (subunits 3+12), and 0.9% had allele e (subunits 2+10). Glu-B1 and Glu-D1 allele frequency differed significantly ( P<0.01) from a previous study of the US Hard Winter Wheat germplasm developed from 1970 to 1990. At LMW-GS loci, five Glu-A3 alleles, nine Glu-B3 alleles, and five Glu-D3 alleles were identified. Ten entries with the null Wx-B1b allele and seven with the null Wx-A1b allele were detected. This survey allows comparisons of HMW-GS and waxy allele compositions with the US Hard Winter Wheat germplasm from previous eras and provides baseline data on LMW-GS composition.