The effect of indirect tests for grain quality on the grain yield and industrial quality of bread wheat.

The objective of this study was to examine the effect of selection using three indirect tests for grain quality on grain yield and dough, and baking properties, measured as alveograph strength, alveograph tenacity/extensibility ratio and loaf volume. The three tests were flour protein content, flour sedimentation and high molecular weight glutenin subunits. Of the indirect tests used for grain quality, sodium dodecyl sulphate (SDS)-sedimentation allowed the highest intensity of selection for a combined trait index of the target grain quality and grain yield characteristics. The top 48% of the material could be retained on the basis of SDS-sedimentation, resulting in retention of atleast two-thirds of the top 10% of genotypes for the combined trait index. Flour protein percentage, a weighted high molecular weight glutenin index and an index combining all the indirect tests — flour protein, SDS-sedimentation and high molecular weight glutenins — gave selection intensities of 61%, 64% and 55%, respectively, for the combined trait index. If the objective of selection is dough strength alone, then a weighted index of all indirect traits (flour protein, SDS-sedimentation and high molecular weight glutenins) provided the highest selection intensity (26%). Other selection intensities for individual target traits were 24% for the prediction of loaf volume from flour protein, 40% for the prediction of tenacity/extensibility ratio using SDS-sedimentation and 68% for the prediction of grain yield using SDS-sedimentation. [ABSTRACT FROM AUTHOR]