Assessment of Genetic Polymorphism in Durum Wheat Genotypes Based on Electrophoretic Profiles of Gliadin-Coding Loci

Abstract

The loss of genetic diversity of crops is one of the global problems of agriculture nowadays. Different methods are currently used for evaluation of genetic polymorphism in plants, which include various types of markers (morphological, molecular etc.). Assessment of genetic diversity based on electrophoretic profiles of seed storage proteins is still considered one of the most precise, simple and economical methods in the marker-assisted selection. The genetic diversity of gliadins has been studied among 50 genotypes of T. durum, using acid polyacrylamide-gel electrophoresis (Acid-PAGE). In total, 33 bands and 50 gliadin patterns were identified. Twelve different bands and 40 patterns were found in ω- gliadins, 8 polymorphic bands and 31 patterns were determined in γ-gliadins, along with 5 bands and 10 different patterns in β-gliadins, and 8 bands in combination resulted in 42 different patterns in the α-gliadin zone. Fifty patterns were found for each of the Gli-1 (γ/ω region) and Gli-2 (α/β region) loci. The genetic diversity index (H) was higher for α-gliadins (0.972), followed by ω and γ-gliadins (0.963 and 0.956, respectively), and the lowest value was detected in β-gliadin patterns (0.825). Cluster analysis based on Jaccard coefficient of similarity divided the analyzed collection into four clusters. The data obtained from electrophoretic analysis of gliadins is highly useful for identification of genotypes and selection of genetically distant varieties for breeding.