Two crosses of high protein-black glumed x low protein-white glumed durum wheat (Triticum turgidum L. var. durum) genotypes were used for quantitative trait loci (QTL) analysis for grain protein percentage (GPP). The black glume colour was used as a genetic marker (M) in an individual marker locus model which allows for the estimation of gene effects and recombination frequencies by comparing marker classes means in the segregating generations (F2, BC1 and BC2). The black glume character was monogenically controlled with co-dominance between the two alleles of the Bg gene. Black-glumed parental landraces showed greater GPP means (18.17) than the white glumed local cultivar (14.38), while the F1 of the two crosses was intermediate (15.23). Meantime, the black-glumed (BgBg) F2 and BC1 plants of the two crosses showed higher GPP means than the two other types (Bgbg and bgbg) of glume colour. The white glumed (bgbg) F2 and BC2 plants had the lowest GPP means. The QTL analysis for GPP revealed that the recombination frequencies between the QTL for high GPP and the M marker for black glumes were 0.11 and 0.15 in the two tested crosses indicating a close linkage between the genes controlling the two characters. The additive (d) gene effects estimated from the QTL analysis were much greater in magnitude (1.67 and 2.28) than the dominance (h) effects (0.22 and 0.50) in the two crosses, respectively. Evidently, marker-assisted selection (MAS) for increasing grain protein percentage could be very effective utilizing the black glume gene as a marker in the segregating populations. The six generations means showed the adequacy of the additive-dominance model and the absence of non-allelic gene interaction. The additive (D) component of variance was greater in magnitude than the dominant (H) with moderate values of narrow-sense heritability being 0.54 and 0.63 in the two crosses.