Date of this Version
Cereal Chemistry, 80(5): 518-523
Wheat (Triticum aestivum L.) genotypes with short mixing times usually have low mixing tolerance values, which make them more ,sensitive to over mixing in commercial bread production. In this study, we evaluated the genotypic and environmental effects on agronomic performance and end-use quality of 27 experimental genotypes (hereafter referred to as mixing tolerant genotypes) which were identified in an initial screen as having short mixing times and good mixing tolerances to 1) determine whether genotypes identified in a preliminary end-use quality screen as lines with usually long tolerances but short mixing times were due to their genotype (G), the environment (E), or G X E; and as these results were unusual, 2) determine whether or not our initial screen predicts end-use quality, and 3) determine the stability of both agronomic and end-use quality traits. The 27 genotypes and five check cultivar, were grown in a randomized complete block design with two replicates in nine environments in 1997 and 1998. All plots were harvested for grain yield. The harvested grain from the first replicate and random genotypes from the second replicate were micromilled to produce flour samples for evaluation of flour yield, protein content and mixograph mixing time and mixing tolerance values. Seed diameter, thousand kernel weight, and kernel hardness were also measured in three environments. Environment, G, and G X E interaction effects (mainly changes in magnitude) were significant for most agronomic and end-use quality parameters Our initial screen, which had identified 27 genotypes, was partially effective in identifying genotypes that have shorter mixing time value, compared with their mixing tolerance values. We identified four genotypes (15%) from the mixing tolerant genotypes that had a good mixing tolerance value and relatively shorter mixing time, as did the released cultivars 'Agate' and 'Scout 66'. However, mixing characteristics values of all genotypes fell within the acceptable limits, indicating our screen effectively identified genotypes with acceptable quality. Mixing tolerant genotypes, which had been identified as having short mixing time scores and long mixing tolerance scores, were considered stable across environments.