Tetraploid Wheat—A Resource for Genetic Improvement of Durum Wheat Quality

The tetraploid relatives (subspecies) of commercial durum wheat (Triticum turgidum L. subsp. turgidum conv. durum (Desf.) MacKey) offer a source of economically useful genes for the genetic improvement of durum cultivars. Tetraploid wheat subspecies show a wide diversity in grain protein composition and content, which are major factors determining the pasta-making quality of durum cultivars. In this study, the specific focus was the identification of accessions expressing one or more superior pasta-making traits. In all, 33 accessions were surveyed representing five different subspecies; var. durum (13 accessions), polonicum (7 accessions), persicum (3 accessions), turanicum (6 accessions), and turgidum (4 accessions). These accessions and the durum cultivars Wollaroi and Kamilaroi (in both years) and Yallaroi (in 1998 only) were grown at Tamworth, Australia in 1997 and 1998. Grain, semolina, and spaghetti cooking quality were evaluated using a range of tests. Several accessions were identified with larger grain size and protein content and higher semolina extraction. Although many of the accessions were weaker in dough strength, a few were equal to the commercial cultivars and produced pasta of comparable quality. The main disadvantage with these accessions was the low yellow color. These quality defects can be corrected by conventional breeding.     

Interactions of Genotype and Glutenin Subunit Composition on Breadmaking Quality of Durum 1AS•1AL‐1DL Translocation Lines

Dual‐purpose durum (Triticum turgidum L. subsp. durum) wheat, having both good pasta and breadmaking quality, would be an advantage in the market. In this study, we evaluated the effects of genotype and varying HMW and LMW glutenin subunit composition on durum breadmaking quality. Genotypes included five near‐isogenic backgrounds that also differed by variability at the Glu‐D1d (HMW subunits 1Dx5+1Dy10), Glu‐B1 (presence or absence of subunit 1By8), and Glu‐B3 (LMWI or LMWII pattern) loci. Quality tests were conducted on genotypes grown at five North Dakota locations. Genotype had a stronger influence on free asparagine content than glutenin subunit composition. Genotypes carrying Glu‐D1d had higher glutenin content than lines that did not carry Glu‐D1d. Among Rugby translocation genotypes, lines carrying LMWI had higher gliadin content and better loaf volume than genotypes carrying LMWII. Absence of 1By8 produced major reductions in loaf volume in nontranslocation lines regardless of whether LMWI or LMWII was present. In contrast, the presence of Glu‐D1d compensated well for the absence of 1By8 regardless of which LMW pattern was present. The durum genotypes did not have loaf volumes equal to bread wheat cultivars, and results suggest that improved extensibility is needed to improve durum breadmaking quality.     

Quality of Spaghetti Made from Full and Partial Waxy Durum Wheat

The waxy character is achieved in durum wheat (Triticum turgidum L. var. durum) when the granule‐bound starch synthase activity is eliminated. The result is a crop that produces kernels with no amylose in the starch. The presence of two Waxy loci in tetraploid wheat permits the production of two partial waxy wheat genotypes. Advanced full and partial waxy durum wheat genotypes were used to study the effect of waxy null alleles on pasta quality. Semolina from full and partial waxy durum wheats was processed into spaghetti with a semicommercial‐scale extruder, and pasta quality was evaluated. Cooked waxy pasta was softer and exhibited more cooking loss than pasta made from traditional durum cultivars. These features were attributed to lower setback of waxy starch as measured with the Rapid Visco Analyser. High cooking loss may be due to the lack of amylose‐protein interaction, preventing the formation of a strong protein network and permitting exudates to escape. Waxy pasta cooked faster but was less resistant to overcooking than normal pasta. Partial waxy pasta properties were similar to results obtained from wild‐type pasta. This indicates that the presence of a single pair of functional waxy genes in durum wheat was sufficient to generate durum grain with normal properties for pasta production. Waxy durum wheat is not suitable for pasta production because of its softening effect. However, this property may offer an advantage in other applications.     

Proteomic analysis by two-dimensional gel electrophoresis and starch characterization of Triticum turgidum L. var. durum cultivars for pasta making

Criteria for durum wheat quality are continuously evolving in response to market pressure and consumer's preference. Specific attributes of durum wheat for different end products require more rapid and objective means to grade and classify wheat parcels based on processing potential. A total of 10 durum wheat cultivars were compared for compositional, protein, and starch characteristics. Mean values for the gross composition differed for total protein, gluten, and starch. Two-dimensional electrophoresis (2DE) analysis showed the proteome diversity among the cultivars. As shown by the principal component analysis (PCA) applied to 2DE data of gliadin and glutenin fractions, cultivars differed mainly from the number of proteins and levels of protein expression. As determined by the rapid viscoanalyzer (RVA), swelling power, starch damage, amylose content, and starch pasting properties of 10 cultivars differed significantly. 2DE fingerprinting and amylose content seemed to distinguish specific cultivars being useful tools for selecting suitable durum wheat cultivars for pasta making.     

Genetic variation for phenolic acids concentration and composition in a tetraploid wheat (<Emphasis Type="Italic">Triticum turgidum</Emphasis> L.) collection

Phenolic acid intake through the consumption of whole-wheat foods provides important health benefits associated with reduced risks of cardiovascular diseases and colon cancer. The genetic variation for phenolic acids was extensively studied in common wheat, but a comprehensive survey in tetraploid wheat is lacking. In this study we evaluated the genetic variability for individual and total phenolic acids concentration existing in a large collection of tetraploid wheat (Triticum turgidum L.). A 2-year evaluation was undertaken on the whole-meal flour of 111 genotypes belonging to seven T. turgidum subspecies including cultivars, landraces and wild accessions. Durum cultivars [T. turgidum subsp. durum (Desf.) MacKey], had the highest average concentration of total phenolic acids (828.7 μg g^?1 dm in 2012; 834.5 μg g^?1 dm in 2013) with amounts varying from 550.9 μg g^?1 dm to 1701.2 μg g^?1 dm, indicating a variation of greater than threefold fold. The lowest concentration of phenolic acids was found in T. turgidum subsp. dicoccum (Schrank ex Schübler) Thell. Rivet wheat (T. turgidum L. subsp. turgidum) had phenolic acid concentrations similar to those in durum, but less variation was noted among the accessions. On the other hand, the accessions of the four remaining subspecies showed lower phenolic acid concentrations and variation among the accessions as compared to durum. A total of six phenolic acids were identified across the wheat genotypes. The effects of genotype, year and year × genotype were estimated by ANOVA and resulted significant for all phenolic acids. The ratio of genotypic variance to total variance suggested the possibility of improving phenolic acid content in elite wheat germplasm through appropriate breeding programs. Moreover, significant correlations between phenolic acids and other quality characteristics of the grain were detected.     

Starch Characteristics of Waxy and Nonwaxy Tetraploid (Triticum turgidum L. var. durum) Wheats

Manufacture of pasta products is paramount for durum wheat (Triticum turgidum L. var. durum). The recent development of waxy durum wheat containing starch with essentially 100% amylopectin may provide new food processing applications and present opportunities for value‐added crop production. This investigation was conducted to determine differences in some chemical and functional properties of waxy durum starch. Starch was isolated from two waxy endosperm lines and four nonwaxy cultivars of durum wheat. One of the waxy lines (WX‐1) was a full waxy durum wheat whereas the other line (WX‐0) was heterogeneous, producing both waxy and nonwaxy seed. Effects on starch swelling, solubility, pasting, gelatinization, and retrogradation were examined. The full waxy starch had four times more swelling power than the nonwaxy durum starches at 95°C, and was also more soluble at three of the four temperatures used. Starch pasting occurred earlier and peak viscosities were greater for starches from both waxy lines than for the nonwaxy starches, but their slurries were less stable with continued stirring and heating. Greater energy was required to melt gelatinized waxy starch gels, but no differences were found in either refrigerated storage or freeze‐thaw retrogradation, as determined by differential scanning calorimetry. The results of this investigation showed some significant differences in the starch properties of the waxy durum wheat lines compared to the nonwaxy durum wheats.     

Nutritional and Quality Traits of Pasta Made from SSIIa Null High‐Amylose Durum Wheat

Food products that are high in fiber and low in glycemic impact are healthier. Amylose is a form of resistant starch that mimics dietary fiber when consumed. A durum wheat (Triticum durum) line was created that lacks starch synthase IIa (SSIIa) activity, a key enzyme in amylopectin biosynthesis, by identifying a null mutation in ssIIa‐B following mutagenesis of a line that has a naturally occurring ssIIa‐A null mutation. Our objective here was to compare seed, milling, pasta, and nutritional characteristics of the SSIIa null line with a wild‐type control line. The SSIIa null line had increased amylose and grain protein with lower individual seed weight and semolina yield. Refined pasta prepared from the SSIIa null semolina absorbed less water, had increased cooking loss, had a shorter cook time, and was considerably firmer even after overcooking compared with the wild‐type line. Color of the SSIIa null cooked and uncooked pasta was diminished in brightness compared with the wild type. Nutritionally, the SSIIa null pasta had increased calories, fiber, fat, resistant starch, ash, and protein compared with the control line, along with reduced total and available carbohydrates. Pasta made from high‐amylose durum wheat provides a significant nutritional benefit along with enhanced end‐product quality via firmer pasta that resists overcooking.     

Grain Quality Characteristics and Milling Performance of Full and Partial Waxy Durum Lines

Mutation of the gene coding for the granule bound starch synthase (waxy protein) leads to reduced amylose content in cereal endosperm. Durum wheat (Triticum turgidum L. var. durum) has one waxy locus in each of its two genomes. Full waxy durum wheat is produced when both genomes carry the waxy null alleles. When only one locus is mutated, partial waxy durum wheat is obtained. Partial and full waxy near‐isogenic lines of durum wheat developed by a breeding program were analyzed as to their quality characteristics. Amylose was largely eliminated in full waxy lines; however, no reduction in amylose content was detected in partial waxy lines. The waxy mutation did not affect grain yield, kernel size, or kernel hardness. Full waxy durum lines had higher kernel ash content, α‐amylase activity, and a unique nonvitreous kernel appearance. Protein quality, as evaluated by SDS microsedimentation value, gluten index, and wet gluten was slightly lower in the full waxy lines than in the other genotypes. However, comparisons with current cultivars indicated that protein quality of all derived lines remained in the range of strong gluten cultivars. Semolina yield was lowered by the waxy mutations due to lower friability that resulted in less complete separation of the endosperm from the bran. Waxy semolina was more sensitive to mechanical damage during milling, but modified tempering and milling conditions may limit the damage. Overall, quality characteristics of waxy durum grain were satisfactory and suitable for application testing.     

Effect of Soft Kernel Texture on the Milling Properties of Soft Durum Wheat

Worldwide, nearly 20 times more common wheat (Triticum aestivum) is produced than durum wheat (T. turgidum subsp. durum). Durum wheat is predominately milled into coarse semolina owing to the extreme hardness of the kernels. Semolina, lacking the versatility of traditional flour, is used primarily in the production of pasta. The puroindoline genes, responsible for kernel softness in wheat, have been introduced into durum via homoeologous recombination. The objective of this study was to determine what impact the introgression of the puroindoline genes, and subsequent expression of the soft kernel phenotype, had on the milling properties and flour characteristics of durum wheat. Three grain lots of Soft Svevo and one of Soft Alzada, two soft‐kernel back‐cross derived durum varieties, were milled into flour on the modified Quadrumat Senior laboratory mill at 13, 14, and 16% temper levels. Samples of Svevo (a durum wheat and recurrent parent of Soft Svevo), Xerpha (a soft white winter wheat), and Expresso (a hard red spring wheat) were included as comparisons. Soft Svevo and Soft Alzada exhibited dramatically lower single‐kernel characterization system kernel hardness than the other samples. Soft Svevo and Soft Alzada had high break flour yields, similar to the common wheat samples, especially the soft hexaploid wheat, and markedly greater than the durum samples. Overall, Soft Svevo and Soft Alzada exhibited milling properties and flour quality comparable, if not superior, to those of common wheat.     

Assessment of variability in salt tolerance based on seedling growth in Triticum durum Desf.

Variability in response to salinity was examined in 29 Triticum durum Desf. accessions or cultivars based upon relative root and shoot lengths of 14-day-old seedlings grown in control and 100 mM NaCl solutions. NaCl caused a significant reduction of root and shoot growth for all accessions/cultivars, but the degree of reduction differed between them. Some cultivars had significantly greater relative root and shoot lengths than others, suggesting that there may be potentially useful variability in salinity tolerance within the durum wheats.     

Genetic Diversity among Syrian Cultivated and Landraces Wheat Revealed by AFLP Markers

Genetic diversity among some important Syrian wheat cultivars was estimated using Amplified Fragment Length Polymorphism (AFLP) markers. Five Triticum aestivum L. and 10 Triticum turgidum ssp. durum were analyzed with 11 EcoRI–MseI primer pair combinations. Of the approximately 525 detected AFLP markers, only 46.67% were polymorphic. Cluster analysis with the entire AFLP data divided all cultivars into two major groups reflecting their origins. The first one contained T. aestivum L. cultivars, and the T. turgidum ssp. durum cultivars and landraces were grouped in the second. Narrow genetic diversity among all cultivars was detected with an average genetic similarity of 0.884. The lowest similarity index (0.9) was found between Cham5 and Hamary (durum wheat), whereas this value was 0.93 between Salamony and Bouhouth 4 (T. aestivum L.). The narrow genetic diversity level indicates that these genotypes could be originated from the same source. AFLP analysis provides crucial information for studying genetic variation among wheat cultivars and provides important information for plant improvement.     

Effect of soil cadmium concentration on three Chilean durum wheat cultivars in four environments

Durum wheat (Triticum turgidum L. var durum) is a species that accumulates cadmium (Cd). Durum wheat cultivars differ in their absorption ability of Cd; therefore, identifying and selecting genetic material with low Cd accumulation reduces human exposure to this toxic element. In the present study, Cd concentration was evaluated in three Chilean durum wheat cultivars (Llareta-INIA, Corcolén-INIA, and Lleuque-INIA) grown in four Chilean locations with varying concentrations of Cd in soils. The objective of this study was to evaluate the response of these durum wheat cultivars to different doses of cadmium in terms of grain yield; Cd concentration in different plant tissues (grain, straw, roots); soil Cd concentration was also evaluated. Results show that grain yield was not affected by soil Cd; differences in Cd concentration in plant tissues were generally associated with location, cultivar, and soil Cd concentration. Grain Cd concentration in all three cultivars was classified in the low accumulation category for this metal; ‘Lleuque-INIA’ noted as having a very low accumulation.     

Analysis of genetic diversity in Tunisian durum wheat cultivars and related wild species by SSR and AFLP markers

Thirty-four durum wheat cultivars representing the Tunisian durum (Triticum durum Desf.) wheat collection and seven wild species of wheat relatives (Triticum turgidum L., T. dicoccon Schrank., T. dicoccoides (Körn) Schweinf., T. araraticum Jakubz., T. monococcum L., Aegilops geniculata Roth, and Aegilops ventricosa Tausch) were analysed with amplified fragment length polymorphism (AFLP) and microsatellite (SSR) markers. Both marker systems used were able to differentiate durum wheat cultivars from the wild relatives and to specifically fingerprint each of the genotypes studied. However, the two marker systems differed in the amount of detected polymorphisms. The 15 SSR markers were highly polymorphic across all the genotypes. The total number of amplified fragments was 156 and the number of alleles per locus ranged from 3 to 24 with an average of 10.4. Two SSR markers alone, Xwms47 and Xwms268, were sufficient to distinguish all 34 durum wheat genotypes. The five AFLP primer pair combinations analysed yielded a total of 293 bands, of which 31% were polymorphic. The highest polymorphic information content (PIC) value was observed for SSRs (0.68) while the highest marker index (MI) value was for AFLPs (7.16) reflecting the hypervariability of the first and the distinctive nature of the second system. For durum wheat cultivars, the genetic similarity values varied between 31.3 and 81% for AFLPs (with an average of 54.2%), and between 3.6 and 72.7% for SSRs (with an average of 19.9%). The rank correlation between the two marker systems was moderate, with r = 0.57, but highly significant. Based on SSR markers, highest genetic similarity (GS) values were observed within the modern cultivars (37.3%), while the old cultivars showed a low level of GS (19.9%). Moreover, the modern cultivars showed low PIC and MI values. UPGMA Cluster analysis based on the combined AFLP and SSR data separated the wild wheat species from the durum wheat cultivars. The modern cultivars were separated from the old cultivars and form a distinct group.     

Analysis of Microsatellite Diversity in Ethiopian Tetraploid Wheat Landraces

The extent and patterns of microsatellite diversity in 141 Ethiopian tetraploid wheat landraces consisting of three species Triticum durum Desf., T. dicoccon Schrank and T. turgidum L. were analyzed using 29 microsatellite markers. A high level of polymorphism and a large number of alleles unique for each species were detected. Compared to emmer (T. dicoccon) and poulard (T. turgidum) wheats, a higher genetic diversity was observed in T. durum. The A-genome was more polymorphic than the B-genome in all the three species. Microsatellites with (GA) _n -repeats had a higher number of alleles than (GT) _n -repeats. A species pairwise comparison was made to determine the percentage of shared alleles and a large number of common alleles among species were observed. Average gene diversity, across the 29 microsatellite loci, was 0.684 for T. durum, 0.616 for T. dicoccon and 0.688 for T. turgidum. Genetic distances were lower between T. durum and T. turgidum (0.26) than between T. durum and T. dicoccon (0.34) or between T. turgidum and T. dicoccon (0.38). A significant correlation (p < 0.01) was found between the number of alleles per locus and the gene diversity in all the three species. Allelic frequency variation was highest between T. turgidum and T. dicoccon (10.62%) and lowest between T. durum and T. turgidum (4.86%). A genetic similarity coefficient of 0.34, 0.46 and 0.37 was found in T. durum, T. dicoccon, and T. turgidum, respectively. The dendogram, which was constructed on the basis of a similarity matrix using the UPGMA algorithm, distinguished all accessions represented in the study.     

New Insights Into the Role of Gluten on Durum Pasta Quality Using Reconstitution Method

The effects of varying the gluten composition at constant protein, protein content at constant composition, and glutenin‐to‐gliadin (glu/gli) ratio on durum semolina rheological properties and the quality of the spaghetti derived from these doughs was investigated using the reconstitution method. Reconstituted flours were built up from a common durum starch and water‐soluble fraction but with varying gluten types from a range of wheats at both 12 and 9% total protein. A 10‐g mixograph and microextensigraph properties were affected by the source of the gluten, which was related to glutenin composition and polymeric molecular weight distribution. Cooked pasta firmness was highly correlated to mixograph development time (MDDT). Furthermore, varying the protein content (9–20%) showed an increase in mixograph peak resistance (PR) with no effect on extensigraph Rmax. Pasta firmness increased and stickiness decreased with increasing protein content. In another experiment, the glutenin and gliadin fractions isolated from durum wheat were added to the respective base semolina to investigate the effect of varying the glu/gli ratio by 1.3–1.6 fold. Increasing the ratio increased MDDT but had no effect on PR and resistance breakdown. Variable effects were obtained for spaghetti firmness. The information obtained should prove useful to durum breeders by providing further evidence for the importance of protein to pasta quality.     

Relationship of Ethanol Yield to Agronomic and Seed Quality Characteristics of Small Grains

Production of fuel ethanol hinges on the availability of carbohydrate sources, with corn being the crop of choice in most areas. However, in some climatic regions, it is not feasible to grow adequate volumes of corn so other starch sources must be utilized. Here we examined various small grain crops commonly grown in the Northern Great Plains for suitability for ethanol production. Four cultivars each of the hexaploid wheat (Triticum aestivum L.) classes hard red spring (HRS), hard white spring (HWS), soft white spring (SWS), along with durum wheat (Triticum durum L.), and four spring barley (Hordeum vulgare L.) cultivars were grown in replicated plots in two environments in 2006. Agronomic and seed quality traits, along with starch content and ethanol yield over a period of 72 hr were measured on all cultivars. Agronomic yield was highest for the barley cultivars and lowest for HRS and HWS. Seed size was greatest for the durum and barley cultivars. The SWS group had the lowest protein content and the highest starch content. Starch content was highly correlated with final ethanol yield and the SWS group was highest in absolute ethanol yield. However, ethanol yield per hectare was highest for barley, with SWS ranking second, while the HRS and HWS groups had the lowest ethanol yields per hectare. The results indicate that selection for small grain ethanol yield should focus primarily upon agronomic yield at the expense of protein content. Traditional selection for high HRS and HWS milling and baking quality is not consistent with maximal ethanol yield per hectare.     

Significance of Aegilops tauschii Glutenin Genes on Breadmaking Properties of Wheat

The contribution of the diploid wild wheat species Aegilops tauschii (DD) to breadmaking quality was studied using synthetic hexaploid wheats (AABBDD) derived from a common Triticum turgidum var. durum (AABB) and three A. tauschii parental lines. Prolamin alleles of the T. durum and A. tauschii parents are additively expressed in the synthetic hexaploids. Bread loaf volumes (BV) assessed by micro-rapid-mix-test (MRMT) and rheological parameters: gluten index (GI), maximum resistance (RE), SDS-sedimentation (SDSS), dough surface, and other quality characteristics clearly indicate that BV and other breadmaking properties in hexaploids are significantly influenced by glutenin genes of the A. tauschii species.     

Effects of Nitrogen Fertilizer on Protein Quantity and Gluten Strength Parameters in Durum Wheat (Triticum turgidum L. var. durum) Cultivars of Variable Gluten Strength

Field studies were conducted over three years at two locations in Saskatchewan, Canada, to determine the effect of nitrogen fertilizer on protein quantity and protein strength in 10 cultivars of durum wheat (Triticum turgidum L. var. durum) representing a range of gluten strength. Increasing nitrogen fertilizer resulted in increased protein content in all cultivars across environments. Cultivars were clearly differentiated on the basis of gluten strength using a gluten index (GI), SDS sedimentation (SDSS), alveograph indices of overpressure (P) and deformation energy (W), mixograph energy to peak (ETP), and mixograph bandwidth energy (BWE) at all fertilizer levels. Variable cultivar response to nitrogen fertilizer was observed only for protein content, GI, and alveograph W. The nature of the cultivar‐by‐fertilizer interaction for GI suggested that the conventional strength cultivars would benefit more from nitrogen fertilizer than the extra‐strong types, which showed no change or slight decreases in GI with nitrogen fertilizer despite an increase in total gluten. SDSS increased with nitrogen fertilizer, following similar trends as protein. Gluten strength rankings of the cultivars by SDSS were maintained with increased fertilizer. Fertilizer had little effect on alveograph P, mixograph ETP, and mixograph BWE. Overall, GI values were more stable across increasing levels of nitrogen fertilizer and resultant increased protein content compared with SDSS, mixograph development time, and alveograph W and L, suggesting it is a good test for estimating intrinsic gluten strength for cultivars with a wide range of protein content.     

Genetic diversity of HMW glutenin subunit in Chinese common wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) landraces from Hubei province

The high molecular weight (HMW) glutenin subunit composition of 111 common landraces of bread wheat collected from Hubei province, China has been determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Ninety six of the accessions were homogeneous for HMW glutenin subunit composition and 15 were heterogeneous. For the Glu-1 loci, 16 alleles were detected, 3 at the Glu-A1locus, 9 at the Glu-B1and 4 at the Glu-D1. Three novel alleles were identified, two at the Glu-B1 and one at the Glu-D1locus. Combination of these 16 alleles resulted in 14 different HMW subunit patterns. The distribution of HMW glutenin subunit alleles in a subset of 105 of the 111 accessions representing six populations was assessed both at the individual population and whole population levels. The results demonstrated that the distribution of allelic patterns varied among populations. Taken together, 62.5% of the alleles detected were considered to be rare alleles while the Glu-A1c (null), Glu-B1b (1Bx7 + 1By8) and Glu-D1a (1Dx2 + 1Dy12) alleles were found most frequently in the six populations. The subset exhibited relatively high genetic diversity (A = 5.33, P = 1.00, Ae = 1.352 and He = 0.238) with 81.5% of the diversity being within populations and 18.5% between populations.     

Polymorphism of high M r glutenin subunits in wild emmer Triticum turgidum subsp. dicoccoides: chromatographic,electrophoretic separations and PCR analysis of their encoding genes

Triticum turgidum subsp. dicoccoides (Körn. ex Asch. et Graebn.) Thell. (AABB), the immediate progenitor of tetraploid and hexaploid wheats, is a species characterised by a wide range of protein polymorphism and by high protein content. Surveys on polymorphism and genetic control of the high molecular weight glutenin subunits (HMW-GS) present in this species, in two forms x- and y-type at the Glu-A1 and Glu-B1 loci, are still considered useful, both to improve technological properties of breeding varieties and to study the genome evolutionary process in wheats. Comparative Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoretic and Reversed Phase High Performance Liquid Chromatographic analyses (SDS-PAGE, RP-HPLC) of the HMW-GS present in several accessions of T. turgidum subsp. dicoccoides allowed the detection of new alleles of Glu-A1 and Glu-B1 loci, with x- and y-type glutenin subunits, apparently similar to those present in cultivated wheats in molecular weight, but different in surface hydrophobicity. In addition, changes in the number of x- and y-type subunits at the glutenin loci were also ascertained. The y-type subunits at the Glu-A1 locus, which are never expressed in cultivated bread and durum wheats, and single y-type expressed glutenin subunits at the Glu-B1 locus were also identified in several accessions. DNA extracted from samples, differing in number or type of HMW-GS and corresponding to x- and y-type genes at Glu-1 loci, were amplified using specific primers, two of which were constructed within the transposon-like sequence of Chinese Spring DNA and analysed by polymerase chain reaction. The results showed this insertion in some accessions of T. turgidum subsp. dicoccoides and also the presence of silent Ax, Bx and By type genes. The usefulness for breeding of these comparative analyses carried out on different HMW-GS alleles detected in Triticum turgidum subsp. dicoccoides, is discussed.