Effect of environment and genotype on durum wheat gluten strength and pasta viscoelasticity

Data on the quality of durum wheat genotypes grown under eight environments (site-year combinations) were evaluated to determine the relative effects of genotype and environment on quality characteristics associated with glut en strength, protein content, and pasta texture. The 10 durum wheat genotyp es assessed in this study represented a range of gluten strength types from the very strong U.S, desert durum genotype, Durex, to the medium strength Canadian genotype, Plenty. Considerable genetic variability was detected fo r all quality characteristics studied Genotype-environment interaction was significant for all quality parameters evaluated, with the exception of mix ograph development time. Genotype-environment interaction was most importan t in determining protein content and least important in determining gluten index, gluten viscoelasticity, and SDS sedimentation volume. The nature of the genotype-environment interaction was evaluated by determining the numbe r of significant crossover (rank change) interactions. There was at least o ne significant crossover interaction between pairs of genotypes and environ ments for five of eight quality traits tested. Of 45 genotype pairs, eight and six showed significant crossover interactions for protein content and p asta disk viscoelasticity, respectively. Significant crossover interactions were at least partially due to the differential response of Canadian genot ypes as compared with U.S, genotypes. With the exception of protein content and pasta disk viscoelasticity, our results suggest that among the selecte d sample of 10 genotypes, genotype-environment interactions were minor and due primarily to changes in magnitude rather than changes in rank.