Main developments in the diverse landscape of milling varietals (3)
This is a summary from Catherine Ravel (geneticist at INRA Clermont-Ferrand) talk during the last AGM.
Modifying wheat storage proteins by selective breeding
Vital to France’s trade balance and the world’s third leading grain, wheat remains of paramount importance, particularly for its use in foods. Almost all the wheat produced is used after processing. These processes depend to a large extent on the viscoelastic properties of gluten, a network formed by the interaction of storage proteins, glutenins and gliadins, after hydration and mixing. Glutenins are principally responsible for the strength and elasticity of dough. Monomeric gliadins contribute mainly to the dough’s viscosity. The technological quality of individual wheats is determined largely by the content and composition of storage proteins. Although storage proteins are essential components for wheat processors, ingesting them can lead to health problems, such as coeliac disease, requiring patients to eliminate gluten completely from their diet.
Storage proteins are the product of well-established, highly polymorphic genes, regulated at several levels including gene transcription. This genetic control offers breeders a means of combining technologically favourable alleles, for example. However, improving protein content, where this is negatively correlated with yield, is a difficult process. Nor should we forget the effect of agronomic measures (fertilisation).