Bread wheat can be used to make different products thanks to the presence of gluten, a protein network that confers unique visco-elastic properties to wheat doughs. Gluten is composed by gliadins and glutenins. The glutenins can be further divided into high and low-molecular-weight glutenins (HMWGs and LMWGs, respectively) and are encoded by Glu-1 and Glu-3 loci. The variability of these genes is associated with differences in quality. Because of this, the identification of novel glutenin alleles is still an important target. In this study, 57 haplotypes or glutenin combinations were registered among a set of 158 Iranian landraces and five novel HMWGs alleles were identified. The landraces were also characterized for several quality traits, including gluten quality, which allowed to associate the different glutenin alleles with low or high quality. Other quality traits examined were iron, zinc, and phytate contents, which are intimately related with the nutritional quality. Important variation for these components was found as well as for the phytate:iron/zinc molar ratios (related to the potential bioavailability of these important micronutrients). The landraces identified in the present study (some of them combining high gluten quality with low phytate:zinc values) could be a useful resource for breeders who aim to improve the wheat end-use quality and especially the content of zinc and its relative bioavailability.

Wild einkorn (Triticum monococcum L. ssp. aegilopoides (Link) Thell.) is a diploid wheat species from the Near East that has been classified as an ancestor of the first cultivated wheat (einkorn; T. monococcum L. ssp. monococcum). Its genome (Am), although it is not the donor of the A genome in polyploid wheat, shows high similarity to the Au genome. An important characteristic for wheat improvement is grain quality, which is associated with three components of the wheat grain: endosperm storage proteins (gluten properties), starch synthases (starch characteristics) and puroindolines (grain hardness). In the current study, these grain quality traits were studied in one collection of wild einkorn with the objective of evaluating its variability with respect to these three traits. The combined use of protein and DNA analyses allows detecting numerous variants for each one of the following genes: six for Ax, seven for Ay, eight for Wx, four for Gsp-1, two for Pina and three for Pinb. The high variability presence in this species suggests its potential as a source of novel alleles that could be used in modern wheat breeding.

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Wheat is one of the most widely grown crops in the world. One of the traits that defines wheat quality is grain hardness, which is determined by puroindolines (PINA and PINB) proteins encoded with Pina-D1 and Pinb-D1 genes. In this study, the diversity of Pina-D1 and Pinb-D1 was evaluated in a collection of 271 Iranian common wheat (Triticum aestivum L. ssp. aestivum) landraces, whose kernels had previously been classified as hard or semi-hard based on PSI analysis. Three alleles previously described as associated with hard grain were detected in the collection: Pinb-D1b in 11 accessions, Pinb-d1ab in 175 accessions, and Pinb-d1p in 80 accessions. In addition, a novel allele tentatively named Pinb-d1ak was detected in Pinb-D1 and was characterized by a change at position 140 of the deduced protein (cysteine/tyrosine). On average, the accessions with this allele showed a lower PSI value than the accessions with other Pin allele. This means that this novel allele may be associated with harder grains than other Pin alleles and could be used by breeding programs targeting different grain hardness levels. This study highlights the importance of conserving and characterizing wheat genetic resources that could be used as sources of genetic variability in breeding programs.

Spelt (Triticum aestivum ssp. spelta) is part of the so-called ancient wheats. These types of wheats are experiencing a revival as they have been proposed to be healthier than conventional wheat. However, the given healthier condition of spelt is not substantiated by solid scientific evidence. The objective of this study was to analyze the genetic variability for several grain components, related to nutritional quality (arabinoxylans, micronutrients, phytic acid) in a set of spelt and common wheat genotypes to determinate if spelt is potentially healthier than common wheat. The results obtained indicated that within the compared species, there is a significant variation in the nutritional compounds, and it is not truthful and accurate to state that one species is healthier than the other. Within both groups, genotypes showing outstanding values for some traits were detected, which could be used in breeding programs to develop new wheat cultivars with good agronomic performance and nutritional quality.