Bread Wheat Grain Research Articles

Assessment of morphological traits as seed and protein yield components in bread wheat (Triticum aestivum L.) cultivars

Effect of different attributes on grain and protein yield of bread wheat was assessed using 20 genotypes. Randomized complete block design with three replications was used. Relationship among measured traits was assessed by Pearson's correlation coefficient and factor analysis. Correlation analysis showed the significant relation of grain and protein yield with all the traits except correlation of grain filling duration and peduncle length with grain yield as well as spike yield and peduncle length with protein yield. Factor analysis based on principal component analysis method and varimax rotation indicated that four important factors accounted for about 98% of the total variation among traits studied. The first factor assigned 48% of total variation between traits and was significantly related with traits grain yield, biological yield, protein yield and protein percentage. This factor was regarded as quantitative and qualitative yield improvement factor. Other factors accounted for 20, 16 and 14% of variation between traits so were entitled as spike yield, grain filling ability and photosynthesis reservoir enhancement factors, respectively. In conclusion, results revealed effect of grain filling rate, biological yield, number of grains/spike, spike yield and protein percentage on grain and protein yield. Hence, these traits are recommended as indirect selection criteria for genetic improvement of grain yield especially in early generations.

Proteomic analysis of middle and late stages of bread wheat (Triticum aestivum L.) grain development

Proteomic approaches were applied in four grain developmental stages of the Chinese bread wheat Yunong 201 and its ethyl methanesulfonate (EMS) mutant line Yunong 3114. 2-DE and tandem MALDI-TOF/TOF-MS analyzed proteome characteristics during middle and late grain development of the Chinese bread wheat Yunong 201 and its EMS mutant line Yunong 3114 with larger grain sizes. We identified 130 differentially accumulated protein spots representing 88 unique proteins, and four main expression patterns displayed a dynamic description of middle and late grain formation. Those identified protein species participated in eight biochemical processes: stress/defense, carbohydrate metabolism, protein synthesis/assembly/degradation, storage proteins, energy production and transportation, photosynthesis, transcription/translation, signal transduction. Comparative proteomic characterization demonstrated 12 protein spots that co-accumulated in the two wheat cultivars with different expression patterns, and six cultivar-specific protein spots including serpin, small heat shock protein, β-amylase, α-amylase inhibitor, dimeric α-amylase inhibitor precursor, and cold regulated protein. These cultivar-specific protein spots possibly resulted in differential yield-related traits of the two wheat cultivars. Our results provide valuable information for dissection of molecular and genetics basis of yield-related traits in bread wheat and the proteomic characterization in this study could also provide insights in the biology of middle and late grain development.

English

Barley ranks third after durum and bread wheat grain production in Algeria. In this study, genetic diversity of twenty nine traditional genotypes of barley was assessed using twenty seven pheno-morphological and agronomic traits in presence of four controls. Very high significant differences were found between genotypes for all quantitative characters statistically analyzed, indicating existence of a great variability within the germplasm. Some traditional genotypes differed from all controls by their better mean values of 1000 grain weight, tiller number per spike, grain number per spike and grain protein content. The long-cycle genotypes had higher values of 1000 grain weight, awn length and plant height than those with short cycle. For quantitative traits, the principle component analysis showed that three components could describe 68.27% of total variances and the cluster analysis divided all six-rowed barley studied into three cluster groups. The following traits: 1000 grain weight, awn length, days to heading and maturity, grain width, grain number per spike, plant height, length of first rachis segment and grain length were those contributing more to variability among the genotypes and also but less strongly the tiller spike number per plant and the spike length. The awn length, the 1000 grain weight, the grain width and the plant height were positively correlated with highly significant correlations between the majority of them. On the qualitative traits, the growth habit, the curvature of the first rachis segment and the lower leaf sheath hairiness were the traits which varied more between all genotypes.      Key words: Qualitative traits, quantitative traits, variability.

Evaluation and prediction of some wheat cultivars productivity in relation to different sowing dates under North Sinai region conditions

Two open-field experiments were conducted during 2011/2012 and 2012/2013 seasons at the experimental farm, Faculty of Environ. Agric. Sciences, EL-Arish, Suez Canal University (31° 08′ 04.3″ N, 33° 49′ 37.2″ E). This work was aimed to evaluate the performance of four bread wheat (Triticum aestivum L.) cultivars i.e.; Misr-1, Sakha-93, Giza-168 and Gemmeiza-9 sown at three sowing dates (15th October, 15th November, 15th December) under the metrological conditions of North Sinai. Results obtained from experimental field studies were used as indicators to test the performance of DSSAT-CSM (Cropping System Model) Ver. 4.5.1.023. Necessary files were prepared as required. Calibration and validation of applying CERES-Wheat model was done through using d-Stat index of agreement between simulated and observed values. Field experiment results indicated that under North Sinai environmental conditions, the significantly highest values of spike length, one thousand kernel weight and radiation use efficiency % were recorded by Gemmeiza-9 cultivar under early sowing date (October, 15). However, the highest values of spike weight, grain yield and dry biological yield were obtained when the same cultivar cultivated under mediate sowing date (mid-November). The output data from the CERES-Wheat model showed that Gemmeiza-9 cultivar recorded the highest observed grain yield in the 1st and 2nd seasons (5352 and 5928kgha−1, respectively) and highest predicted grain yield (3957 and 4619kgha−1, respectively) in mediate sowing date (mid-November) as compared to other wheat cultivars Misr-1, Sakha-93 and Giza-168. Generally, Gemmeiza-9 under mediate sowing date (November, 15) is recommended treatment to maximized bread wheat grain yield under North Sinai environmental conditions and all similarity regions.

Effects of seed-gall nematode, Anguina tritici, on bread wheat grain characteristics and yields in Turkey

The effects of Anguina tritici on wheat yields and agronomic components were investigated at Thrace Agricultural Research Institute, Turkey, during the 2013 and 2014 growing seasons. Evaluations during 2013 focused on the wheat cv. Pehlivan, which is widely cultivated in Turkey. In this cultivar, A. tritici led to a grain infection in infected spikes of 0-100%, with an average of 61.8%. In 2014, yield losses caused by A. tritici were investigated in four wheat cvs, Pehlivan, Selimiye, Gelibolu and Kate-A. Results indicated that there were significant yield losses averaging 55% in plots infested with A. tritici (average yields = 3.74 t ha−1), as compared to control plots (average yields = 8.38 t ha−1). Yield losses in the four wheat cvs Kate-A, Pehlivan, Selimiye and Gelibolu were estimated as 51.3, 53.2, 56.6 and 59.6%, respectively, with seed infection levels by A. tritici of 21.4, 20.9, 24.4 and 18.3%, respectively.

Sequential zinc and iron biofortification of bread-wheat grains: from controlled to uncontrolled environments

The development of knowledge on bread wheat (Triticum aestivum L.) biofortification in zinc (Zn) and iron (Fe), related to its potential agronomical use and the nutritional and technological implications, is becoming important to strategies for improving human nutrition. In this context, we studied the accumulation of Zn and Fe in grains, considering potential uptake and translocation kinetics, photoassimilate production and deposition, and related yields, in grains of cv. Roxo produced under controlled-environment conditions and used thereafter in field trials. The metabolic plasticity of this wheat genotype grown under controlled-environment conditions allowed a 10- and 4-fold enhancement in accumulation of Zn and Fe in the grains after nutrient supplementation with a 5-fold concentrated Hoagland solution (5S), after two generations. Moreover, when these seeds were sown under field conditions and the resulting plants supplemented with or without Zn and Fe, the accumulation of these nutrients decreased within the next two generations. Such field seeds obtained without further Zn and Fe supplementation (with nitrogen only; F3(S) and F4(S)) maintained enhanced levels of Zn (~400%) and Fe (40–50%) compared with the initial seeds. If Zn and Fe supplement was given to the plants germinated from F2(5S), the subsequent F3(5S) and F4(5S) seeds maintained the Zn increase (~400%), whereas a further enhancement was observed for Fe, to 75% and 89%, respectively. Toxic limits were not reached for photosynthetic functioning. Even under the highest Zn and Fe supplement dose given to the F3(5S) plants, there was only a slight effect on photosystem II photochemical performance; in fact, enhanced net photosynthesis values were observed. In conclusion, within this experimental design, Zn and Fe biofortification can be obtained without toxicity effects on photosynthetic performance and with negligible modifications to grain texture and nutritional value (protein quality and contents as well as fatty acids).

Marker-assisted development of bread wheat near-isogenic lines carrying various combinations of purple pericarp (Pp) alleles

The commercial interest in pigmented wheat grain flows from an understanding that they are nutritionally superior to white kernels. The pigment of purple coloured bread and durum wheat grains results from the accumulation of anthocyanins in the pericarp; its genetic basis is the action of Pp-1 and Pp3 genes. Here, the development of a set of bread wheat near isogenic lines (NILs) carrying various combinations of Pp alleles is described, along with a demonstration of their utility for the genetic dissection of the purple pericarp trait. A marker-assisted backcrossing strategy was based on the use of microsatellite markers linked to Pp3 (chromosome 2A), Pp-A1 (7A) and Pp-D1 (7D). Pp-A1 is a newly uncovered gene of weak effect. A qRT-PCR-based analysis of the anthocyanin synthesis structural genes [Chi (chalcone-flavanone isomerase) and F3h (flavanone 3-hydroxylase)] transcript abundance in the pericarp of the NILs suggested that the Pp genes up-regulate their transcription in contrasting ways. These NILs represent a resource for studying the effect of grain pigmentation on other wheat traits and end products.

Path Analysis of Grain Yield and Yield Components and Some Agronomic Traits in Bread Wheat

Development of new bread wheat cultivars needs efficient tools to monitor trait association in a breeding program. This investigation was aimed to characterize grain yield components and some agronomic traits related to bread wheat grain yield. The efficiency of a breeding program depends mainly on the direction of the correlation between different traits and the relative importance of each component involved in contributing to grain yield. Correlation and path analysis were carried out in 56 bread wheat genotypes grown under field conditions of Maragheh, Iran. Observations were recorded on 18 wheat traits and correlation coefficient analysis revealed grain yield was positively correlated with stem diameter, spike length, floret number, spikelet number, grain diameter, grain length and 1000 seed weight traits. According to the variance inflation factor (VIF) and tolerance as multicollinearity statistics, there are inconsistent relationships among the variables and all traits could be considered as first-order variables (Model I) with grain yield as the response variable due to low multicollinearity of all measured traits. In the path coefficient analysis, grain yield represented the dependent variable and the spikelet number and 1000 seed weight traits were the independent ones. Our results indicated that the number of spikelets per spikes and leaf width and 1000 seed weight traits followed by the grain length, grain diameter and grain number per spike were the traits related to higher grain yield. The above mentioned traits along with their indirect causal factors should be considered simultaneously as an effective selection criteria evolving high yielding genotype because of their direct positive contribution to grain yield.

The effect of manuring on cereal and pulse amino acid δ15N values

Amino acid δ15N values of barley (Hordeum vulgare) and bread wheat (Triticum aestivum) grains and rachis and broad bean (Vicia faba) and pea (Pisum sativum) seeds, grown in manured and unmanured soil at the experimental farm stations of Rothamsted, UK and Bad Lauchstädt, Germany, were determined by GC-C-IRMS. Manuring was found to result in a consistent 15N-enrichment of cereal grain amino acid δ15N values, indicating that manuring did not affect the metabolic routing of nitrogen (N) into cereal grain amino acids. The increase in cereal grain δ15N values with manuring is therefore due to a 15N-enrichment in the δ15N value of assimilated inorganic-N. Greater variation was observed in the 15N-enrichment of rachis amino acids with manuring, possibly due to enhanced sensitivity to changes in growing conditions and higher turnover of N in rachis cells compared to cereal grains. Total amino acid δ15N values of manured and unmanured broad beans and peas were very similar, indicating that the legumes assimilated N2 from the atmosphere rather than N from the soil, since there was no evidence for routing of 15N-enriched manure N into any of the pulse amino acids. Crop amino acid δ15N values thus provide insights into the sources of N assimilated by non N2-fixing and N2-fixing crops grown on manured and unmanured soils, and reveal an effect of manure on N metabolism in different crop species and plant parts.

Additive main effects and multiplicative interaction (AMMI) and GGE-biplot analysis of genotype × environment interactions for grain yield in bread wheat (Triticum aestivum L.)

The combine ANOVA analysis for grain yield of 10 wheat genotypes at 12 environments showed that bread wheat grain yields were significantly affected by E (environment), which explained 75.01% of the total treatment (G+E+GEI) variation, whereas the G (Genotype) and GEI were significant and accounted for 9.48 and 15.5% respectively. Additive main effects and multiplicative interaction (AMMI) analysis indicated that three principal components (PCAs) were significant (P < 0.01). PCA 1, PCA 2, and PCA 3 accounted for 65.49, 17.10 and 10.11% of the GE interaction, respectively. A GGE-biplot based on genotype-focused scaling was depicted in order to detect the locations of genotypes, whereas the wheat genotypes were divided into 4 groups based on their scores of PCA1 and PCA2. The first group included on 3 stable genotypes (G2, G10 and G6) that were highest yielding. As for Group 2 included 2 unstable genotypes (G4 and G1) that were higher yielding, while the Group 3 (G5, G7 and G8) were low yielding and stable genotypes, and Group 4 consist of 2 genotypes (G9 and G3) that were low yielding and genotypic instability. The correlation coefficients among the 12 test environments and the vector view of the GGE-biplot provide a succinct summary of the interrelationship between the environments. Among 67 correlation coefficients, 38 of which were significant. All environments were positively correlated except that environment E5 negatively correlated with E9, E12 and E10. Key words: Additive main effects and multiplicative interaction (AMMI), additive main effects and multiplicative interaction, bread wheat, genotype-by-environment interaction (GEI), genotype x environment interaction, GGE-biplot, multi environment trials (METs), principal component (PC).

Effect of temperature on lutein esterification and lutein stability in wheat grain

The creamy colour of many wheat-based end-products is conferred by endogenous lutein. During post-harvest storage of grain, free lutein may be converted in part to potentially more stable lutein mono- and di-fatty acid esters. This study investigates the synthesis of lutein esters and stability of free lutein and lutein esters over a wide range of temperatures in grain of a high lutein bread wheat, Triticum aestivum L. line DM5685*B12 and a durum, Triticum durum L cv Kamilaroi. Disappearance of free lutein and lutein esterification followed first order reaction rates. The maximum rate of lutein esterification was at ≈80 °C, however, the optimum temperature for maximum synthesis with minimum degradation was between 30 °C and 60 °C. No ester synthesis was observed at temperatures higher than 120 °C. The data are consistent with an enzyme participating in the esterification reaction. Lutein esters were found to be more stable than free lutein with a longer shelf life at 60 °C whilst at temperatures ≤40 °C, lutein degradation was minimal. This study provides new information on lutein ester formation and lutein stability that should be useful to grain handlers and food manufacturers seeking to optimise retention of lutein for the benefit of consumers.

English

The combined ANOVA analysis for grain yield of ten wheat genotypes at 12 environments showed that bread wheat grain yield was significantly affected by environment, which explained 75.01% of the total treatment (genotype + environment + genotype by environment interactions) variation, whereas the G and GEI were significant and accounted for 9.48 and 15.5%, respectively. The additive main effects and multiplicative interactions (AMMI) analysis indicated that three principal component analysis (PCA) were significant (P < 0.01). PCA 1, 2 and 3 accounted for 65.49, 17.10 and 10.11% of the genotype + environment (GE) interaction, respectively. Graphical display of genotype by environment interaction (GGE-biplot) based on genotype-focused scaling was depicted in order to detect the locations of genotypes, whereas the wheat genotypes were divided into four groups based on their scores of PCA 1 and 2: Three stable and high yielding genotypes (G2, 10 and 6), two unstable high yielding genotypes (G4 and 1), three stable low yielding genotypes (G5, 7 and 8) and two low yielding unstable genotypes (G9 and 3). The correlation coefficients among the twelve test environments and the vector view of the GGE-biplot provided a succinct summary of the interrelationship between the environments whereby only 38 of the 67 correlation coefficients were significant. All environments were positively correlated except the environment E5 which was negatively correlated with E9, 12 and 10. The G10 (Giza 168) is adaptable for a wide range of environment conditions. Key words: Additive main effects and multiplicative interactions (AMMI), additive main effects and multiplicative interaction, bread wheat, genotype by environment interaction (GEI), genotype x environment interaction, principal component analysis (PCA).

Association study of wheat grain protein composition reveals that gliadin and glutenin composition are trans-regulated by different chromosome regions

Wheat grain storage protein (GSP) content and composition are the main determinants of the end-use value of bread wheat (Triticum aestivum L.) grain. The accumulation of glutenins and gliadins, the two main classes of GSP in wheat, is believed to be mainly controlled at the transcriptional level through a network of transcription factors. This regulation network could lead to stable cross-environment allometric scaling relationships between the quantity of GSP classes/subunits and the total quantity of nitrogen per grain. This work conducted a genetic mapping study of GSP content and composition and allometric scaling parameters of grain N allocation using a bread wheat worldwide core collection grown in three environments. The core collection was genotyped with 873 markers for genome-wide association and 167 single nucleotide polymorphism markers in 51 candidate genes for candidate association. The candidate genes included 35 transcription factors (TFs) expressed in grain. This work identified 74 loci associated with 38 variables, of which 19 were candidate genes or were tightly linked with candidate genes. Besides structural GSP genes, several loci putatively trans-regulating GSP accumulation were identified. Seven candidate TFs, including four wheat orthologues of barley TFs that control hordein gene expression, were associated or in strong linkage disequilibrium with markers associated with the composition or quantity of glutenin or gliadin, or allometric grain N allocation parameters, confirming the importance of the transcriptional control of GSP accumulation. Genome-wide association results suggest that the genes regulating glutenin and gliadin compositions are mostly distinct from each other and operate differently.

Cereal grain, rachis and pulse seed amino acid δ15N values as indicators of plant nitrogen metabolism.

Natural abundance δ(15)N values of plant tissue amino acids (AAs) reflect the cycling of N into and within plants, providing an opportunity to better understand environmental and anthropogenic effects on plant metabolism. In this study, the AA δ(15)N values of barley (Hordeum vulgare) and bread wheat (Triticum aestivum) grains and rachis and broad bean (Vicia faba) and pea (Pisum sativum) seeds, grown at the experimental farm stations of Rothamsted, UK and Bad Lauchstädt, Germany, were determined by GC-C-IRMS. It was found that the δ(15)N values of cereal grain and rachis AAs could be largely attributed to metabolic pathways involved in their biosynthesis and catabolism. The relative (15)N-enrichment of phenylalanine can be attributed to its involvement in the phenylpropanoid pathway and glutamate has a δ(15)N value which is an average of the other AAs due to its central role in AA-N cycling. The relative AA δ(15)N values of broad bean and pea seeds were very different from one another, providing evidence for differences in the metabolic routing of AAs to the developing seeds in these leguminous plants. This study has shown that AA δ(15)N values relate to known AA biosynthetic pathways in plants and thus have the potential to aid understanding of how various external factors, such as source of assimilated N, influence metabolic cycling of N within plants.

Selection and hydroponic growth of bread wheat cultivars for bioregenerative life support systems

As part of the ESA-funded MELiSSA program, the suitability, the growth and the development of four bread wheat cultivars were investigated in hydroponic culture with the aim to incorporate such a cultivation system in an Environmental Control and Life Support System (ECLSS). Wheat plants can fulfill three major functions in space: (a) fixation of CO2 and production of O2, (b) production of grains for human nutrition and (c) production of cleaned water after condensation of the water vapor released from the plants by transpiration. Four spring wheat cultivars (Aletsch, Fiorina, Greina and CH Rubli) were grown hydroponically and compared with respect to growth and grain maturation properties. The height of the plants, the culture duration from germination to harvest, the quantity of water used, the number of fertile and non-fertile tillers as well as the quantity and quality of the grains harvested were considered. Mature grains could be harvested after around 160days depending on the varieties. It became evident that the nutrient supply is crucial in this context and strongly affects leaf senescence and grain maturation. After a first experiment, the culture conditions were improved for the second experiment (stepwise decrease of EC after flowering, pH adjusted twice a week, less plants per m2) leading to a more favorable harvest (higher grain yield and harvest index). Considerably less green tillers without mature grains were present at harvest time in experiment 2 than in experiment 1. The harvest index for dry matter (including roots) ranged from 0.13 to 0.35 in experiment 1 and from 0.23 to 0.41 in experiment 2 with modified culture conditions. The thousand-grain weight for the four varieties ranged from 30.4 to 36.7g in experiment 1 and from 33.2 to 39.1g in experiment 2, while market samples were in the range of 39.4–46.9g. Calcium levels in grains of the hydroponically grown wheat were similar to those from field-grown wheat, while potassium, magnesium, phosphorus, iron, zinc, copper, manganese and nickel levels tended to be higher in the grains of experimental plants. It remains a challenge for future experiments to further adapt the nutrient supply in order to improve senescence of vegetative plant parts, harvest index and the composition of bread wheat grains.

Effect of tillage system on bread wheat yield and grain quality in the temperate semiarid central zone of La Pampa

Effect of tillage system on bread wheat yield and grain quality in the temperate semiarid central zone of La Pampa

Apigenin di-C-glycosides (ACG) content and composition in grains of bread wheat (Triticum aestivum) and related species

Apigenin di-C-glycosides (ACGs) are present in the grain of bread wheat and other related cereals primarily as one or two sets of Wesseley-Moser isomers containing either arabinose and glucose (ACG1) or arabinose and galactose (ACG2) on the A ring of apigenin. These compounds may contribute to the yellow colour of wheat-based products made under alkaline conditions and in addition, have possible roles in a number of plant physiology processes and human health. The aims of this investigation were to survey genetic variation for ACG content and composition in hexaploid bread wheat (Triticum aestivum L.) and to examine ACGs in the putative progenitors of hexaploid wheat and available genetic stocks as a first step towards understanding the mechanisms involved in their biosynthesis and genetic control. Substantial variation in both grain ACG content and the ratio, ACG1/ACG2, were identified within bread wheat cultivars and related species. Genotype controlled the major portion of the variation. ACG content appeared to be a multigenic trait whereas variation in ACG1/ACG2 was associated with a limited number of chromosomes, in particular chromosomes 1B, 7B and 7D. The results suggest that it should be possible to manipulate both ACG content and composition traits through breeding.

A comparison of contents of group A and B trichothecenes and microbial counts in different cereal species

Concentrations of trichothecenes and the amounts of microbial biomass were compared in grain of bread wheat, durum wheat, triticale, rye, oat and barley. Grain samples came from lines regionalised in Poland grown under identical climatic and agricultural conditions in 2007. Among the six analysed cereals, the highest mean concentration of toxic metabolites of 151.89 µg/kg was found for grain of Triticum durum, whereas the lowest was for barley grain (25.56 µg/kg). The highest contamination with microscopic fungi was recorded in case of barley and rice grain (mean concentrations of ergosterol were 12.53 mg/kg and 11.24 mg/kg, respectively). In case of the analysed cereals, the total microbial biomass expressed in the amount of ATP turned out to be the highest (4.7 × 105 relative light units [RLU]) for rye and oat (3.2 × 105 RLU). The results of the applied classical discrimination analysis indicate a significant diversification of species in terms of all the 11 analysed metabolites.

Pleiotropic increases in free non‐polar lipid, glycolipid and phospholipid contents in waxy bread wheat (Triticum aestivum L.) grain

Diethyl ether-extractable free lipid (FL), non-polar or neutral lipid (NL), glycolipid (GL) and phospholipid (PL) contents and water-saturated 1-butanol (WSB)-extractable non-starch lipid (NSL)-monogalactosyldiglyceride (MGDG), digalactosyldiglyceride (DGDG) and phosphatidylcholine (PC)-contents in bread wheat (Triticum aestivum L.) grain were evaluated to elucidate the possible influence of the Wx-D1 gene on the lipid composition. Waxy near-isogenic lines with a non-functional Wx-D1d allele showed consistently increased NL, GL and PL contents among FL and MGDG, DGDG and PC contents among NSL compared with non-waxy near-isogenic lines with a functional Wx-D1a allele throughout three growing/harvest seasons. However, the proportion of NL, GL and PL among FL was not influenced by the non-waxy/waxy state of the endosperm. The nearly non-functional Wx-D1f allele influenced the FL and NL contents in a similar manner to the non-functional allele across two seasons, while the partly functional Wx-D1g allele only affected the NL content. The Wx-D1 locus has pleiotropic effects on the diethyl ether-extractable FL, NL, GL and PL contents and WSB-extractable MGDG, DGDG and PC contents of bread wheat grain. The non-functional Wx-D1d allele causes an increase in the levels of these lipids.

Characterization of Proteins from Grain of Different Bread and Durum Wheat Genotypes

The classical Osborne wheat protein fractions (albumins, globulins, gliadins, and glutenins), as well as several proteins from each of the four subunits of gliadin using SDS-PAGE analyses, were determined in the grain of five bread (T. aestivum L.) and five durum wheat (T. durum Desf.) genotypes. In addition, content of tryptophan and wet gluten were analyzed. Gliadins and glutenins comprise from 58.17% to 65.27% and 56.25% to 64.48% of total proteins and as such account for both quantity and quality of the bread and durum wheat grain proteins, respectively. The ratio of gliadin/total glutenin varied from 0.49 to 1.01 and 0.57 to 1.06 among the bread and durum genotypes, respectively. According to SDS-PAGE analysis, bread wheat genotypes had a higher concentration of α + β + γ-subunits of gliadin (on average 61.54% of extractable proteins) than durum wheat (on average 55.32% of extractable proteins). However, low concentration of ω-subunit was found in both bread (0.50% to 2.53% of extractable proteins) and durum (3.65% to 6.99% of extractable proteins) wheat genotypes. On average, durum wheat contained significantly higher amounts of tryptophan and wet gluten (0.163% dry weight (d.w.) and 26.96% d.w., respectively) than bread wheat (0.147% d.w. and 24.18% d.w., respectively).