Combination of null alleles with 7Â +Â 9 allelic pair at Glu-B1 locus on the long arm of group 1 chromosome improves wheat dough functionality for tortillas

Deletion of one or more high molecular weight glutenin subunit (HMW-GS) alleles alters gluten functionality in ways that can be exploited to design wheat for specialty products. In this work, we investigated whether combining 7 + 9 allelic pair at Glu-B1 locus with deletion of other HMW-GS alleles at Glu-A1or Glu-D1 locus would produce ideal gluten functionality for tortillas. Flours from 17 wheat lines were evaluated for insoluble polymeric protein (IPP) content and gluten properties. Tortillas were produced by hot-press method and evaluated during 16 days storage. Compared to non-deletion lines, deletion line generally had lower IPP (362 vs 414 mg/g); produced more extensible dough (44.9 vs 33.4 mm), which required lower equilibrium force to compress (4.12 vs 7.55 N); and produced larger diameter tortillas (180 vs 165 mm). In general, deletion lines produced tortillas with poor flexibility (score <3.0) after 16 days. However, combination of 7 + 9 allelic pair at Glu-B1 locus with deletions at Glu-A1 or Glu-D1 consistently produced large diameter tortillas that retained good flexibility during 16 days of storage. The 7 + 9 allelic pair at Glu-B1 plays a crucial role in wheat gluten functionality essential for tortillas, and may be a good target for genetic improvement of wheat for flatbreads.