Effects of genotype and environment on glutenin polymers and breadmaking quality

Six genotypes of hard red spring (HRS) wheat were grown at seven environments in North Dakota during 1998. Effects of genotype and environment on glutenin polymeric proteins and dough mixing and baking properties were examined. Genotype, environment, and genotype-by-environment interaction all significantly affected protein and dough mixing properties. However, different protein and quality measurements showed differences for relative influences of genotype and environment. Total flour protein content and SDS-soluble glutenin content were influenced more by environmental than genetic factors, while SDS-insoluble glutenin content was controlled more by genetic than environmental factors. Significant genotypic and environmental effects were found for the size distribution of SDS-soluble glutenins and between SDS-soluble and SDS-insoluble glutenins as well as % SDS-insoluble glutenins. With increased flour protein content, the proportions of monomeric proteins and SDS-insoluble glutenin polymers appeared to increase, but SDS-soluble glutenins decreased. Flour protein content and the size distribution between SDS-soluble and SDS-insoluble glutenin polymers were significantly correlated with dough mixing properties. Environment affected not only total flour protein content but also the content of different protein fractions and size distributions of glutenin polymers, which, in turn, influenced properties of dough mixing. Flow protein content, % SDS-insoluble glutenin polymers in flour, and ratio of SDS-soluble to SDS-insoluble glutenins all were highly associated with dough mixing properties and loaf volume.