Genetic diversity for gliadin patterns of durum wheat landraces in the Northwest of Iran and Azerbaijan

The objective of this study was to identify gliadin band patterns and the extent of genetic diversity in durum wheat genotypes from Northwestern Iran and the Republic of Azerbaijan. Gliadins from 46 landraces and four cultivars were evaluated through acid PAGE analyses. Sixty-six polymorphic bands and 81 patterns were identified. Twenty-four different motility bands and 22 patterns were found in the ω gliadin region with 14 polymorph bands and 20 patterns for α and γ gliadins, and 14 bands and 19 different patterns for β gliadins. The combination of these patterns generated 38 and 39 combinations for Gli-1 and Gli-2 loci, respectively. The genetic diversity index (H) was higher for α gliadins (0.924), followed by ω and γ gliadins (0.899 and 0.878, respectively), and for β gliadin patterns (0.866). Extensive polymorphism (H = 0.875) was observed in four gliadin pattern regions, with higher genetic diversity in the Iranian landraces than in the Azerbaijani ones. Each genotype had special identifying patterns in the gliadin acid PAGE analysis, and cluster analysis based on Jaccard's similarity coefficients formed six groups. Gliadin has a simple, repeatable and economic analysis, and can be used in genetic studie

Addressing global wheat issues one-grain-at-a-time, based on gliadin alleles

For decades, electrophoretic analysis of wheat‐gliadin composition has been a valuable approach to elucidating the genetic constitution of a grain sample, providing this information even at the single‐grain level. An early example was the characterisation of the mix of wheat varieties in a truckload of wheat suspected of being stolen from a country wheat silo in north‐western NSW. Much wider uses of gliadin composition have included tests of genetic non‐uniformity (the presence of biotypes) to study the reasons for variations in grain quality for specific varieties.In the global picture, Australian varieties were found to have considerable non‐homogeneity, but not so great as for some countries. However, it can be argued that a degree of genetic non‐homogeneity can offer some advantages. In parallel with these studies, we examined the global range of cultivars for possible genetic erosion during the twentieth century; no general narrowing of genetic polymorphism was found throughout this period. The analysis of gliadin alleles for many wheat cultivars revealed important relationships at country and regional levels. For example, the cultivars of certain Australian states showed closer relatedness than for other combinations of states. Internationally, Australian wheats were more closely related to varieties from Mexico than to cultivars of many other countries, based on a global set of 290 cultivars bred throughout the twentieth century

Proposal for combining the classification systems of alleles of Gli-1 and Glu-3 loci in bread wheat (Triticum aestivum L.)

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