Genetic responses in milling, flour quality, and wheat sensitivity traits to grain yield improvement in U.S. hard winter wheat

Authors: VAN DER LAAN, LIZA - Oklahoma State University; GOAD, CARLA - Oklahoma State University; Tilley, Michael - Mike; DAVIAL-EL RASSI, GUADALUPE - Oklahoma State University; BLAKEY, ADRIENNE - Oklahoma State University; RAYAS-DUARTE, PATRICIA - Oklahoma State University; HUNGER, ROBERT - Oklahoma State University; DE OLIVEIRA SILVA, AMANDA - Oklahoma State University; CARVER, BRETT - Oklahoma State University

Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2020
Publication Date: 4/22/2020
Citation: Van Der Laan, L., Goad, C.L., Tilley, M., Davial-El Rassi, G., Blakey, A.M., Rayas-Duarte, P., Hunger, R.M., De Oliveira Silva, A., Carver, B.F. 2020. Genetic responses in milling, flour quality, and wheat sensitivity traits to grain yield improvement in U.S. hard winter wheat. Journal of Cereal Science. https://doi.org/10.1016/j.jcs.2020.102986.
DOI: https://doi.org/10.1016/j.jcs.2020.102986

Interpretive Summary: A recent issue of concern is the belief that current wheat is less healthy compared to wheat from a century ago. Part of this concern is fueled by the rise in celiac disease and other forms of gluten intolerance. A series of hard red winter (HRW) wheat cultivars and elite experimental lines (n=28-30) bred for or adapted to the U.S. southern Great Plains were grown in 2015 and repeated through 2018. Analysis of agronomic, grain and flour properties including measurement of the gluten content using a clinically relevant antibody-based assay, and the carbohydrate fructan. Grain yield and kernel size showed a stepwise increase over cycles, whereas grain protein content decreased. The reduced protein content, however, did not result in lower dough strength pertinent to bread baking applications. Data showed a general increase in gluten strength, whereas flour levels of the immunotoxic peptide fragment from gluten. The oligosaccharide fructan, present in milled and wholemeal flours, increased with increasing grain yield potential. The rise in fructans does implicate potentially new dietary concerns for certain individuals with fructan intolerance. To our knowledge, this study is the first to quantify differences in fructan content in an historic North American bread wheat panel featuring incremental changes in yield.

Technical Abstract: A rising global population necessitates continued genetic improvement of wheat (Triticum aestivum L.), but not without oversight of unintended consequences. This oversight is partly to blame for emergence of a bilateral “gluten crisis.” The objectives were to re-establish trends of genetic progress in agronomic and milling traits using a generational yardstick as the timeline rather than cultivar release date, and to measure direct and indirect responses in flour quality and human wheat-sensitivity indicators. Grain yield and kernel size showed a stepwise increase over cycles, whereas grain protein content decreased by one percentage point. The reduced protein content, however, did not result in lower dough strength pertinent to bread baking applications. A novel method of directly testing gluten elasticity via the compression-recovery test indicated a general increase in gluten strength, whereas the ratio of total polymeric to total monomeric proteins remained stable across cycles. Also showing no change with genetic progress in yield were flour levels of the key immunotoxic 33-mer peptide fragment. The oligosaccharide fructan, present in milled and wholemeal flours, increased with increasing grain yield potential. The gluten crisis appears largely unfounded, although the rise in fructans does implicate potentially new dietary concerns for certain individuals with fructan intolerance.