Les bases génétiques et l’utilisation des marqueurs associés à l’amélioration de la qualité des blés

Abstract

Bread making is the major use of wheat. Changes in bread making processes have therefore resulted in changes in the technological properties of the wheat required. These requirements have been met thanks to genetic markers associated with the rheological characteristics of dough. The diversity of storage proteins, and mainly that of high and low molecular weight glutenin subunits (encoded at 3 Glu-1 locus and 3 Glu-3 locus, respectively), plays a major role in genetic differences in gluten properties and is widely used in wheat breeding. Grain hardness, which is characterised by adhesion of the protein matrix to the starch granules, determines the major wheat uses and their technological value. Breeders dispose of genetic markers (non-functional markers) of the major locus Ha/ha influencing grain hardness. The value of the technological characteristics of wheat for bread making is also, to a lesser extent, influenced by arabinoxylanes. The amount of arabinoxylanes strongly influences dough stickiness and its water retention capacity. One major QTL has been identified and breeders have tools to use in reducing the amount of arabinoxylanes in wheats for biscuit-making and mono gastric feed. Today the search for progress in the processability of bread wheat is oriented towards factors associated with nutrition and consumer health. To this end, approaches based on transcriptomics and proteomics of the developing endosperm or the aleurone layer - the part of the grain that is particularly rich in vitamins and minerals - should enable identification of markers for further improvement of bread wheat.