Grain quality and yield characteristics of D-genome disomic substitution lines in 'Langdon' (Triticum turgidum var. durum)

Sets of D-genome disomic substitution lines of ‘Langdon’ (Triticum turgidum var. durum) were used to study the effect of chromosome substitutions on grain yield and flour technological properties. In general, the substitution of any D-genome chromosome had a detrimental effect on grain yield and growth vigour (some lines were sterile). SDS-sedimentation, SE-HPLC and two-gram mixograph procedures were used to measure dough strength of the lines studied. Significant correlations were observed between protein concentration and grain yield and other quality parameters such as SDS-sedimentation value, the proportion of glutenin, dough mix time and peak resistance. Most of the quality characters were highly correlated with each other. Substitution of chromosomes 1D, 5D, 2D and 7D resulted in positive responses to SDS-sedimentation values, but only chromosome 1D had positive effects on the proportion of peak 1 (P₁%), measured by SE-HPLC. Besides the major influence of chromosome 1D on three major mixograph parameters (mixing time, peak resistance and resistance breakdown), chromosome 5D also exhibited significant effects on these mixing parameters. Principal-component analysis showed that the predominant effect on durum-wheat rheological properties was from chromosome 1D, whereas chromosome 5D had a major effect on grain hardness (50%) and increased the whiteness of the flour.