Abstract only

The content of storage proteins (gliadins and glutenins ), known as gluten proteins, in wheat grain exceeds 80%. Gluten has unique physical and chemi- cal properties and basically determines the techno- logical, nutritive and taste properties of wheat bread. Polymorphic proteins are very convenient as objects of population genetics studies, enabling to better understand the inheritance patterns and gene expression during the ontogenesis. Assessment of polymorphism ofthe proteins provides for better clarification of the phylogenetic links for developing a natural system of the organism. Advantages of the polymorphic protein systems as genetic markers include the stability of component make-up of these proteins, which is not affected by variability of environment. Wheat gliadins are heterogeneous proteins consisting of a number of electrophoretic compo- nents. Gliadins are wheat proteins controllable by gene clusters localized in Triticum aestivum on the short arms of chromosomes I A, I B, I D, 6A, 6B and 6D, and in T durum on the short arms of chro- mosomes IA, IB,6Aand6B.Atthegliadin-coding loci of one cluster, there can be genes coding for subunits at varied electrophoretic mobility. Therefore, a biochemical classification of heterogeneous proteins should always be accompanied by genetic analysis. This would considerably enhance the opportunities of obtaining full information on the structure and functional role of these proteins, let alone that only a genetic classification allows for using proteins as effective genetic markers. Investigation of genetically determinable po- Iymorphism of the storage proteins (gl iadins) through the sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) enabled to identify genotypes of some durum wheat lines distributed throughout Azerbaijan. Electrophoresis enables to identify as the polymorphism ofthe durum wheat entries so the frequency of occurrence of the gliadin alleles. The allelic variants of gliadin-coding loci controlling biosynthesis of the storage proteins can serve as a genetic marker of valuable agronomic traits in grain crops. In addition, electrophoresis of grain endo- sperm of Ae. speltoides, Ae. squarossa, T mono- coccum and T aestivum revealed polymorphism between their electrophoregrams and phylogenetic associations between the taxa. Figure below presents gliadin electropho- regrams of the durum wheat genotypes. For the sake of comparison, the gliadin elektrophoregrams of these samples were conditionally divided into four zones: a-,b-,g-, w-gliadin, respectively. Variety Shark (ascribed to Leucurum) was taken as a tester, (EF2). Polymorphism of the gliadin components is basically observed in the w-, g-and b- zones. All electropho- regrams ofthe durum wheat genotypes by gliadin- coding loci Gld 1 A, Gld 1 B, Gld 6A are identified. In T durum val: Reichenbachi (EF 12-13) a new allele Gld 6B was identified. The results of the study suggest that every taxon, variety or line has its specific cereal crop gliadin EF component, which is independent from the environment.

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection