Applicability of 'glume color' controlled by Rg-B1 locus as a field-marker to detect Glu-B3 alleles encoding low-molecular-weight glutenin subunits in common wheat

Glu-B3 alleles on chromosome 1BS of common wheat (Triticum aestivum L.) encoding low-molecular-weight glutenin subunit are associated with dough property. Among them, Glu-B3g is known to increase dough strength. To incorporate efficiently Glu-B3g allele into breeders’ lines, DNA marker-assisted selection (DNA-MAS) is considered to be a powerful tool. In the present study, we examined the applicability of ‘glume color’ (GC) controlled by Rg-B1 (Rg1) locus on 1BS as a ‘field-marker’ to detect Glu-B3 alleles. Three populations of F4 breeding lines were used. In each cross, both genotypes of Glu-B3 and Rg-B1 loci of each parent were different. Glu-B3 allele-specific DNA markers were applied to determine the genotype of Glu-B3 locus of each line. The genotype of Rg-B1 locus of each line was visually determined by GC. Significantly tight cosegregations between Glu-B3 and Rg-B1 loci were found in all the populations of breeding lines. It is considered that GC controlled by Rg-B1 locus is a useful ‘field-marker’ to detect Glu-B3 alleles, as it is less time-consuming and more cost effective than DNA-MAS. By using the ‘field-marker’, breeders can select elite lines carrying Glu-B3g allele in breeding fields only by observing the GC of each line/plant without laboratorial procedures for DNA-MAS.