Identification and quality characterization of a putative novel 17x + 8y high-molecular-weight glutenin subunit...

High-molecular-weight glutenin subunits (HMW-GSs) are major determinants of dough rheological behavior and bread-making quality in bread wheat (Triticum aestivum L.). Among wheat genomes, the Glu-B1 locus exhibits the highest allelic diversity; however, recombination events between x- and y-type HMW-GS genes are considered extremely rare. The identification of novel recombinant HMW-GS profiles may therefore provide valuable new sources of functional diversity for wheat quality improvement.

In the present study, a backcross breeding strategy combined with speed breeding was employed to introgress the 7^OE + 8y HMW-GS combination into a strong-gluten wheat background carrying the 17x + 18y subunits. During the backcrossing process, a putative recombinant HMW-GS profile comprising 17x + 8y was identified based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and segregation patterns and was subsequently stabilized through successive generations. Near-isogenic lines (NILs) carrying 7^OE + 8y, 17x + 18y, and the recombinant 17x + 8y combinations were subsequently evaluated for grain quality, flour functionality, dough rheological behavior, and bread-making performance using the weak-gluten cultivar 'Bayraktar' as a control. Significant differences were observed among NILs for sedimentation value, protein-related quality traits, dough rheology, and bread texture characteristics. NIL 7^OE + 8y exhibited the highest sedimentation value (27.3 mL), followed by NIL 17x + 18y (25.5 mL), whereas the recombinant 17x + 8y line showed a comparatively lower sedimentation value (20.6 mL). In contrast, NIL 17x + 8y exhibited significantly higher damaged starch content and elevated water absorption capacity, indicating distinct flour functionality associated with the recombinant HMW-GS profile. The highest bread loaf volume was recorded in NIL 17x + 18y. Bread texture analyses demonstrated substantially lower hardness values in NILs carrying 17x + 18y, 17x + 8y, and 7^OE + 8y compared with the 'Bayraktar' cultivar during storage.

Overall, the 17x + 18y NIL exhibited stronger gluten-related characteristics and greater loaf volume than the 17x + 8y NIL under the conditions evaluated. However, because the lines also differed in total protein concentration, these differences cannot be attributed exclusively to the presence of the 18y versus 8y subunit. The putative recombinant 17x + 8y profile nevertheless exhibited distinct flour functionality and may represent a valuable genetic resource for further investigation and specialized end-use applications. The results indicate that the putative recombinant 17x + 8y HMW-GS profile represents a novel source of functional variation affecting dough rheology and bread-making performance in bread wheat. However, DNA-level characterization will be required to definitively confirm the underlying recombination event. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.