Combined use of gliadins and SSRs to analyse the genetic variability of the Spanish collection of cultivated diploid wheat (Triticum monococcum L. ssp. monococcum)

This work studied the combined use of gliadins and SSRs to analyse inter- and intra-accession variability of the Spanish collection of cultivated einkorn (Triticum monococcum L. ssp. monococcum) maintained at the CRF-INIA. In general, gliadin loci presented higher discrimination power than SSRs, reflecting the high variability of the gliadins. The loci on chromosome 6A were the most polymorphic with similar PIC values for both marker systems, showing that these markers are very useful for genetic variability studies in wheat. The gliadin results indicated that the Spanish einkorn collection possessed high genetic diversity, being the differentiation large between varieties and small within them. Some associations between gliadin alleles and geographical and agro-morphological data were found. Agro-morphological relations were also observed in the clusters of the SSRs dendrogram. A high concordance was found between gliadins and SSRs for genotype identification. In addition, both systems provide complementary information to resolve the different cases of intra-accession variability not detected at the agro-morphological level, and to identify separately all the genotypes analysed. The combined use of both genetic markers is an excellent tool for genetic resource evaluation in addition to agro-morphological evaluation

Wheat Seed Proteins: Factors Influencing Their Content, Composition, and Technological Properties, and Strategies to Reduce Adverse Reactions

Wheat is the primary source of nutrition for many, especially those living in developing countries, and wheat proteins are among the most widely consumed dietary proteins in the world. However, concerns about disorders related to the consumption of wheat and/or wheat gluten proteins have increased sharply in the last 20 years. This review focuses on wheat gluten proteins and amylase trypsin inhibitors, which are considered to be responsible for eliciting most of the intestinal and extraintestinal symptoms experienced by susceptible individuals. Although several approaches have been proposed to reduce the exposure to gluten or immunogenic peptides resulting from its digestion, none have proven sufficiently effective for general use in coeliac-safe diets. Potential approaches to manipulate the content, composition, and technological properties of wheat proteins are therefore discussed, as well as the effects of using gluten isolates in various food systems. Finally, some aspects of the use of gluten-free commodities are discussed

Gliadins of common wheat: polymorphism and genetics

International audienc

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

Gliadin genotypes worldwide for spring wheats (Triticum aestivum L.) 2. Strong differentiation of polymorphism between countries and regions of origin

Genotypes of 290 cultivars from ten countries (four continents) of spring wheat Dittman aestivum, were analyzed through the identification of alleles at the gliadin-encoding (Gli) loci. The group of cultivars bred in one country during the 20th century might be characterized by its level of genetic diversity (H) and a specific set of alleles. Strong differences between genotypes of cultivars bred in different countries were confirmed by cluster analysis of genetic distances. Genotypes of cultivars bred in regions of the same country might differ, but they always composed a single cluster and strongly differed from genotypes from other countries or regions. Therefore, world polymorphism of spring wheat germplasm of the 20th century is highly structured and differentiated between countries and their regions. This differentiation seems to be mainly a result of natural selection acting in different ways in different eco-climatic conditions of breeding and propagation. At a regional scale, statistically significant temporal changes in frequency of some gliadin alleles and a tendency to temporal decrease of overall genetic diversity were discovered in cultivars bred in each of seven regions studied in Australia, Canada and the former USSR. In regions of Canada (provinces of Manitoba and Ontario) and of the former USSR (Saratov), a statistically significant decay of the genetic diversity of cultivars bred during the 20th century was discovered. However, the influence of breeders' selection for end-use wheat quality on the wheat genetic diversity was the least, if any

Gluten alleles and predicted dough-quality for wheat varieties worldwide: a great resource - free on the AACCI international website

The gluten composition of more than 8,500 wheat varieties is provided in two new databases on the AACC International website (www.aaccnet.org/ initiatives/definitions/Pages/Gluten.aspx). The databases augment earlier versions (1-3) by providing a program to screen the large volume of data. For each variety, the program provides the gliadin composition, listed as alleles at the Gli-1 and Gli-2 loci; the high molecular weight subunits of glutenin (HMW-GS), as subunit numbers and alleles at the Glu-1 loci; the low molecular weight subunits of glutenin (LMW-GS), as alleles at the Glu-3 loci; the Payne Glu-1 scores for dough quality; and estimates of dough strength (as Rmax) and extensibility based on both HMW-GS and LMW-GS alleles