Analysis of gliadin patterns and diversity in Triticum polonicum L. accessions from Ethiopia

<p>Gliadins from 25 accessions represented by 350 individual seed samples were analysed by acid-polyacrylamide gel electrophoresis (A-PAGE) with the objective of identifying gliadin band patterns and examine the extent of diversity in <em>Triticum polonicum </em>L. collections from Ethiopia. Seventy polymorphic bands and 68 different patterns were identified. Eighteen different mobility bands and 16 patterns were identified in <em>ω</em>-gliadin region, 22 bands and 20 patterns in <em>γ-</em>gliadin region, 12 bands and 22 patterns in <em>β-</em>gliadin region and 18 bands and 10 patterns in <em>α</em>-gliadin region. The average genetic diversity calculated from the data of the four gliadin zones of the analysed samples was 0.15. The γ region have the highest diversity (H = 0.193), followed by ω regions (H = 0.177) and β region (H = 0.168) and the lowest diversity was observed in α region (H = 0.127). Cluster analysis based on genetic distances resulted in grouping of the analysed accessions in to seven main groups. Though the level of diversity was relatively lower than other tetraploid wheat species from Ethiopia, the findings are indicative of the existence of variation in the collections which can be exploited for wheat improvement.</p>

Assessment genetic diversity of einkorn genotypes (Triticum monococcum L.) by gliadin electrophoresis

<p>The genetic diversity of gliadins in twenty two einkorn accessions preserved under long-term seed storage condition in the National gene bank of Bulgaria were evaluated, using acid polyacrylamide-gel electrophoresis (Acid-PAGE). In total, 64 polymorphic bands and 22 gliadin patterns were identified. Thirty four different mobility bands and 21 gliadin patterns were identified in the ω-gliadin zone, 12 bands and 16 patterns were noted in the γ-gliadins, 17 patterns and 12 mobility bands were found for β-gliadins and six bands with five different α -gliadin patterns were determined. The genetic diversity index (H) was the highest for ω-gliadins (0.950), followed by β-gliadins (0.924) and γ- (0.914), respectively and the lowest value was detected in α-gliadin patterns (0.120). Cluster analysis based on the UPGMA method and Nei and Li similarity coefficients classified all the genotypes into 3 main groups. No relationships between genetic diversity, geographic origin and the genotypes were observed. The results of cluster analysis justify the high level of genetic variation among investigated einkorn accessions.</p>

Genetic structure analysis of leaf rust resistant triticale accessions from the VIR collection using gliadin patterns

The gliadin banding patterns of important accessions from the collection of the N. I. Vavilov All‑Russian Institute of Plant Genetic Resources (VIR) registered in the form of “protein formulas” provide reliable information for the preparation of a “protein passport” for each accession and is convenient for storage and computer processing. It helps to control originality and integrity of accessions during regeneration and their use in breeding. The study involved 17 triticale accessions resistant to leaf rust. The analysis was carried out on single grains of the original accession (a sample of 13–26 kernels) according to the standard protocol adopted by VIR and approved by the International Seed Testing Association (ISTA). The gliadin electrophoretic banding patterns of triticale accessions were registered in the form of “protein formulas”; polymorphism of each accession and genetic diversity within the collection were estimated, and genetic structure of accessions was identified based on the marker protein components. A large variety of the revealed genotypes opens a possibility to identify accessions that combine resistance with other useful traits. Stable and polymorphic accessions including from 2 to 7 biotypes were found. The discovery of interbiotype hybrids and recombinant genotypes in the composition of some polymorphic accessions indicates the instability of their genetic structure and the ongoing formation process. This is due to the heterogeneity of the original parental forms, the tendency to cross‑pollination and insufficiently thorough selection. The data on the triticale genotypic structure can be used in introgressive breeding to control the transfer of rye genetic material to wheat varieties in order to increase their immunity and resistance to adverse factors.

Composition, protein contents, and microstructural characterisation of grains and flours of emmer wheats (Triticum turgidum ssp. dicoccum) of the central Italy type

The microstructural characteristics were evaluated of two types of Italian Farro (Triticum turgidum ssp. dicoccum) with spring and autumn growth habits, the former with a vitreous tendency and the latter with a floury tendency. Common wheat flours and grains (Triticum aestivum) were used as controls. Protein fractions such as glutenin and gliadin were extracted from Triticum turgidum ssp. dicoccum flours and studied by SDS-PAGE in order to make a comparison between the electrophoretic analyses and microstructural studies which were conducted on the same samples using Scanning Electron Microscopy (SEM and Cryo-SEM). The results obtained by SDS-PAGE showed that the gliadin patterns of both emmer samples were similar, while the common wheat gliadins showed a band at 90 kDa that was not present in the gliadin fraction of emmer. When the glutenin patterns were analysed, the autumn emmer did not show the low molecular weight protein bands (16&ndash;23 kDa) whilst spring emmer wheat appeared more similar to common wheat. Regarding the microstructural characteristics of the kernels, spring (vitreous tendency) emmer showed starch granules covered by protein to a higher extent than autumn emmer. These differences were also observed in flours. The gluten of spring emmer wheat was observed as a homogeneous structure showing similarities with common wheat gluten, while autumnal emmer gluten appeared more heterogeneous and lacking in structure. &nbsp;

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 studies