Gliadins polymorphism and cluster analyses of Syrian grown durum wheat.

A total of 187 Triticum durum (Desf.) genotypes were studied. These included 102 mutants, 15 local genotypes, 22 lines from ACSAD and 48 lines from ICARDA. Polyacrylamide gel electrophoresis under acidic conditions of pH 3.1 (A-PAGE) was used to separate gliadins groups of storage proteins for the identification and the classification of the genotypes under study. Results showed that the region of w-gliadins had a wider range for the number of bands than all other regions of gliadins (a-,  b- ,   and  g-gliadins). Cluster analyses using the Unweighted Pair Group Mean Average (UPGMA) method put the genotypes of all groups in trees on the basis of the gliadin bands distribution. Three categories were obtained. 1) Complete correspondence of the pedigrees and the trees, reflecting the importance of the gliadins as a decisive factor for the genotype position in the cluster. 2) The presence of genotypes with similar banding patterns but were unrelated in their pedigrees. And, 3) The genotypes originate from the same cross but are unrelated in the tree. It was concluded that tree clustering based on gliadin electrophoregrams may be used as an additional tool in revealing genetical relations among genotypes. However, one should keep in mind that several factors may influence the resulting tree. These include heterogeneity, incorrect band designation and uncertain or false pedigrees.