Genetic audit of wheat: researchers determine the actual variability of a gene responsible for bread quality
Gluten is responsible for bread having a spongy crumb, pizza dough being stretchy, and pasta not falling apart when cooked. It is its viscoelastic protein network that makes wheat so special. The proteins responsible for part of this "magic" of wheat flour doughs are glutenins, which wheat breeders have studied for decades.
For more than 40 years, the research community has identified multiple variants (alleles) of the GLU-B1 gene, which encodes two high-molecular-weight glutenin subunits that are key to the quality of wheat-based products. Accordingly, the Catalogue of Gene Symbols for Wheat includes up to 98 alleles (different versions of the GLU-B1 gene). The problem is that, until now, not all the identified alleles found in different wheats around the world had been compared with each other.
In this context, researchers from the Department of Genetics at the University of Córdoba — Francisco Andrade, Juan Bautista Álvarez, and Carlos Guzmán — have carried out a genetic review to check whether the genetic variability described is correct or was overestimated. "We collected wheats carrying these alleles from all over the world, studied their GLU-B1 variants, and compared them with each other," explains researcher Carlos Guzmán.
Following this genetic audit, "we found that this variability was overestimated and that many of the alleles were duplicated or triplicated when we compared them with each other. Of the 98 alleles recorded, the actual variability is less than half," says researcher Francisco Andrade.
This verification of the genetic variability of this gene, which is key to gluten quality, has been an exercise in genetic archaeology. After delving into the scientific literature in which the alleles were identified, the team had to contact numerous germplasm banks around the world to obtain the material, which originated from 33 different countries. These wheats, from countries such as Nepal, Ethiopia, and Mexico, have been reviewed and curated to create a master set (a representative set of wheats) available to the breeding community that wants to work with these alleles to improve wheat quality. "Now, teams that are going to conduct studies with the different versions of this gene will only have to go to a germplasm bank, where the genetic material representing the variability of that gene will be held. All the wheats will be available together as a single collection with their alleles identified and without duplication," explains Carlos Guzmán.
Thus, in addition to confirming the actual genetic variability of this gene, they are providing plant breeders worldwide with a tool to improve the genetic quality of wheat.
Advances through gene identification
The same team carried out similar work years earlier, but with the GLU-A1 gene (also involved in encoding glutenins). That work highlighted the value of a rare variant of the GLU-A1 gene that improves baking quality and increases the protein content in the grain. Estonian researcher Marina Tikhonova worked with this allele in collaboration with the Córdoba team in a study that sought to develop a molecular marker to facilitate wheat breeding processes. Thanks to the identification of the alleles by the Córdoba team, it was possible to develop a practical application: molecular markers to make breeding processes using this allele more efficient.
These studies are part of the Hardiwheat research project, led by Carlos Guzmán, whose main objective is to identify and validate genetic variability and make it available for use in breeding programs focused on the development of higher-yielding and higher-quality wheats.
References:
Andrade, F.; Álvarez, J. B. & Guzmán, C. (2026). Development of a germplasm master set covering the variability of high molecular weight glutenin subunits for the GLU-B1 locus in Triticum sp. Journal of Cereal Science. 130, 104505. https://doi.org/10.1016/j.jcs.2026.104505 .
Journal of Cereal Science
Experimental study
Not applicable
Development of a germplasm master set covering the variability of high molecular weight glutenin subunits for the GLU-B1 locus in Triticum sp.
5-Jul-2026