SDS Sedimentation Test Research Articles

Genome wide association mapping of end-use gluten properties in bread wheat landraces (Triticum aestivum L.)

Numerous studies have aimed to dissect the genetic basis of wheat end-use quality, yet the consideration of gluten aggregation properties in this context has been limited despite its important role in determining the processing quality. This study has addressed the evaluation of the end-use quality of a collection of 189 Spanish bread wheat (Triticum aestivum L.) landraces. For phenotyping, we utilized the GlutoPeak methodology to assess gluten aggregation traits, the SDS-sedimentation test to measure gluten strength and NIR for grain protein content. In addition to previous genotyping data with numerous DArT-seq markers distributed across the entire wheat genome, we developed ten KASP-based molecular markers designed for GLU-1 loci, which encode high molecular weight glutenins (HMW-GS). The reliability of these markers was thoroughly assessed. Our genome-wide association analysis (GWAS) focused on gluten properties and protein content, revealed 89 marker-trait-associated loci (MTAs). These loci were further grouped into 50 MTA-QTLs across various chromosomes based on linkage disequilibrium. While some MTA-QTLs overlapped with regions identified in other studies, others represented novel genomic regions. Inside these regions, we identified several candidate genes with gluten quality-related annotated functions or grain-specific expression patterns, which represent potential targets for marker development and future wheat end-use quality improvement.

Investigation of Suitable Pakistani Wheat Cultivars for Preparation of Quick Cooking Bulgur

The purpose of this research was to evaluate the aptness of Pakistani commercial wheat cultivars Durum-97, Faisalabad-8, Punjab-11, Galaxy-13, Ujala-16 and Annaj-17 aptnessfor bulgur preparationthrough thousand kernel weight (43-47 g), grain size (length 5-7, width 2-3, thickness 2-3 mm), particle size index (16-24 %), single kernel characterization system (hardness 45-74 HI, weight 34-36 mg, moisture 9-10 %, diameter in-between 2mm) respectively. All varieties were parboiled for 3 suitable periods (regarding in dimensions40, 60, 80 min) at constant temperature. Bulgur was evaluated in various nutritional and quality attributes. Color analysisvalue was (L* 56-64, a* -1˗ -3, b* 17-21 of colorimeter). SDS-sedimentation test (19-25 mL), zeleny value (46-60 mL) and SDS-PAGE friabilin protein (presence and absence) while Durum-97 and Anaj-17 lack these proteins. Proximate analysis of wheatcarries (ash 0-1, crude protein 12-15, crude fiber 1-2, and crude fat 1-3 %). Likewise proximate analysis of bulgur shows (0-1 ash, 12-15 crude protein, 1-2 crude fat and crude fiber). Mineral analysis revealed (Ca 367-534, Fe 49-33, Zn 23-18, Na 311-171, K 774-952 mgkg-1). Consumers overall acceptance (sensory evaluation) recommends Anaj-17 and Punjab-11 among allvarieties. Conclusively, there is a need to explore more indigenous wheat cultivars as this is the staple food and a value added product.

Allelic Variation at Glutenin Loci (Glu-1, Glu-2 and Glu-3) in a Worldwide Durum Wheat Collection and Its Effect on Quality Attributes.

Durum wheat grains (Triticum turgidum L. ssp. durum) are the main source for the production of pasta, bread and a variety of products consumed worldwide. The quality of pasta is mainly defined by the rheological properties of gluten, an elastic network in wheat endosperms formed of gliadins and glutenins. In this study, the allelic variation at five glutenin loci was analysed in 196 durum wheat genotypes. Two loci (Glu-A1 and Glu-B1), encoding for high-molecular-weight glutenin subunits (HMW-GS), and three loci (Glu-B2, Glu-A3 and Glu-B3), encoding for low molecular weight glutenin subunits (LMW-GS), were assessed by SDS-PAGE. The SDS-sedimentation test was used and the grain protein content was evaluated. A total of 32 glutenin subunits and 41 glutenin haplotypes were identified. Four novel alleles were detected. Fifteen haplotypes represented 85.7% of glutenin loci variability. Some haplotypes carrying the 7 + 15 and 7 + 22 banding patterns at Glu-B1 showed a high gluten strength similar to those that carried the 7 + 8 or 6 + 8 alleles. A decreasing trend in grain protein content was observed over the last 85 years. Allelic frequencies at the three main loci (Glu-B1, Glu-A3 and Glu-B3) changed over the 1915–2020 period. Gluten strength increased from 1970 to 2020 coinciding with the allelic changes observed. These results offer valuable information for glutenin haplotype-based selection for use in breeding programs.

Bread making possibility of Algerian durum wheat (Triticum turgidum L. var.durum) varieties

Actually, gluten strenght, yellow pigment content and protein quality paly an axial role in durum wheat selection. In order to characterize the baking quality of Algerian germplasm, we used eighteen (18) local and improved durum wheats cultivars. The present study showed the presence of significant differences within our genetic resources for several traits. SDS sedimentation test results suggested that, Ofanto, Bidi17, Mexicali, Saoura were classified in the same rank as Marzak, which are considered the best cultivars, with a very high gluten strength and a top score(8)revealed by a mixoragraphy test, these varieties are important for bread making. Yellow pigments analysis showed that, Saoura, Oued Elbared and Waha presented a high yellow pigment content than the check Louiza known for its high yellow index. These results are very motivating to be used in Algerian selection program.

Durum Buğday Genotiplerinin (Triticum durum L.) Yüksek Sıcaklık Şartlarında Verim ve Bazı Kalite Özellikleri Yönünden Değerlendirilmesi

Güneydoğu Anadolu Bölgesi 1. ve 2. alt bölgeleri sulu yağışa dayalı şartlarında 2006/2007 yetiştirme döneminde yürütülen bu çalışmada; 25 durum buğday genotipinin tane verimi (TV) ile birlikte performans oranı (PERO) başaklanma süresi (BS) bin dane ağırlığı (BTA), hektolitre ağırlığı (HL), protein oranı (PO), mini SDS sedimentasyon testi (mSDS) ve tane rengi (b) gibi kalite özellikleri incelenmiştir. Tane verimi bakımından en yüksek değerler Diyarbakır sulu (695 kg da-1) ve kuru (638 kg da-1) şartlarından alınırken, en düşük verim de (301 kg da-1) dane doldurma döneminde yüksek sıcaklığın hüküm sürdüğü (>35 oC) Mardin-Göllü lokasyonundan alınmıştır. Çevre ve özellikler arası ilişkileri belirlemeye esas biplot analizinde, Göllü lokasyonu PO, mSDS ve b değeri bakımından öne çıkarken, Diyarbakır kuru ve sulu lokasyonları ise TV, BTA, HL, BS ve BB bakımından öne çıkmıştır. Genotip stabiliteleri bakımından G16 ve G7 yüksek verim seviyesine sahip spesifik bölgelere uygun genotipler olarak tanımlanırken G14 ise genel adaptasyon kabiliyeti en uygun genotip olarak belirlenmiştir.

Nitrogen management, cultivars and growing environments on wheat grain quality

ABSTRACT The aim of this study was to evaluate the influence of nitrogen (N) fertilization, environment and cultivars on the protein concentration, sodium dodecyl sulfate sedimentation test (SDSS) volume and falling number in wheat. The experimental design was a randomized blocks in split plot scheme with four repetions. Four wheat genotypes were evaluated under six N managements in four enviroment (subplots). The wheat genotypes evaluated were IPR Catuara TM, BRS Gaivota, Quartzo and CD 120. Protein concentration, SDS sedimentation test, falling number and grain yield were evaluated. Combined analysis of variance for the four environment was performed and means were compared by Tukey test at p ≤ 0.05. The environmental effect is greater than the genotype and N effects on protein concentration. The increase in protein concentration reduces grain yield of the cultivars tested. SDSS and falling number in wheat are influenced by the interaction between cultivar and environment and also by the N management. The protein concentration of grain has low influence on SDS sedimentation volume, so the topdressing N management has less accentuated effect on this response variable. The falling number does not vary among cultivars when the environment is suitable to pre-harvest sprouting. The use of topdressing N influences the falling number in wheat.

Degradation of gluten proteins by Fusarium species and their impact on the grain quality of bread wheat

The protein quality of wheat, the most important crop worldwide, is affected by the presence of fungi, mainly those belonging to the Fusarium genus. The aim of this study is to analyze the effects of Fusarium spp. on ground wheat grains quality by measuring gluten strength and quantifying the gliadin/glutenin content. A total of 23 Fusarium spp. isolates and two bread wheat (Triticum aestivum L.) genotypes with contrasting baking quality were used in the investigation. The results of SDS sedimentation test (SDSS) revealed that the presence of Fusarium species significantly affected the gluten strength negatively; while F. pseudograminearum and F. graminearum are the species that predominantly affected the SDSS values. Principal component analysis of gluten composition showed that the effect of Fusarium species on gluten composition depended on the wheat genotypes analyzed. Cluster analysis revealed that all the Fusarium species used as inoculum produced severe effects on grain quality and gluten composition on both the genotypes. In summary, our results showed that the presence of Fusarium spp. impaired storage proteins affecting the wheat dough properties. Therefore, constant monitoring is necessary to reduce the presence of Fusarium in the food chain for reducing the negative potential impact on bread quality.

Molecular characterization and marker development for high molecular weight glutenin subunit 1Dy12** from Yunnan hulled wheat

High molecular weight glutenin subunits (HMW-GSs) play an important role in affecting dough viscoelasticity and extensibility. In this work, the novel HMW-GS gene 1Dy12** in Yunnan hulled wheat was cloned and characterized, and the molecular marker for identifying this gene was developed. SDS-PAGE analysis indicated that the mobility of 1Dy12** was the same as that of 1Dy12. The coding sequence of 1Dy12** was 1953 bp, which was 33 bp less than that of 1Dy12. 1Dy12** possessed 649 amino acid residues and showed a similar molecular structure to the published y-type subunit. It possessed four domains: a signal peptide, a conservative N-terminal domain, a large repetitive domain, and a conservative C-terminal domain. Eight cysteine residues were present in 1Dy12**, which was one more than the conserved number of cysteine residues in the y-type subunit. In vitro SDS-sedimentation tests demonstrated that 1Dy12** could bring higher SDS-sedimentation volumes than those of 1Dy10 or 1Dy12. A set of functional markers for the 1Dy12** gene was developed and validated on 36 bread wheat varieties with different Glu-1 alleles and 48 recombinant inbred lines derived by Yunnan hulled wheat and Yanzhan 1. The markers could effectively distinguish 1Dy12** from other HMW-GS genes and, thus, provide a useful tool for marker-assisted selection in wheat quality improvement programs.

Synergistic Effect of Sulfur and Nitrogen in the Organic and Mineral Fertilization of Durum Wheat: Grain Yield and Quality Traits in the Mediterranean Environment

In recent years, awareness on sustainable land use has increased. Optimizing the practice of nitrogen fertilization has become crucially imperative in cropping management as a result of this current trend. The effort to improve the availability of organic nitrogen has incurred a bottleneck while seeking to achieve a high yield and quality performance for organic winter cereals. Field experiments were conducted, under rainfed Mediterranean conditions, over a period of two subsequent growing seasons. The objective was to investigate the effect of soil and foliar S application on the performance of three durum wheat cultivars fertilized with either organic or inorganic N. The hypothesis to be verified was if different S fertilization strategies could improve grain yield and quality when coupled with mineral or organic N fertilizer. There were three levels of treatment with mineral N fertilizer (120, 160 and 200 kg ha−1), two levels of organic N fertilizer (160 and 200 kg ha−1), two levels of S fertilizer applied to the soil (0 and 70 kg ha−1), and two levels of foliar S application at flag leaf stage (0 and 5 kg ha−1). Cultivars were Dylan, Iride and Saragolla. Analyzed traits were grain yield, yield components and quality features of grain. Overall, at the same N rate, grain yield and quality were markedly higher for mineral than organic N source. Cultivar × Year × N treatment interactions significantly affected grain yield and quality indices. Iride showed a high yield stability throughout the mineral N rates in the most favorable year (2011) and, in the same year, was the top performing cultivar in organic N treatments. Dylan was the top performing cultivar for protein content, while Saragolla for the SDS sedimentation test. Soil S fertilization had no effect on grain quality, whereas it significantly increased grain yield (+ 300 kg ha−1) when coupled with organic rather than a mineral N source. However, foliar S application at flag leaf stage did not affect grain yield, but it significantly enhanced quality indices such as test weight (81 vs. 79.9 kg hL−1), protein content (13.7% vs. 12.9 %) and SDS value (72.5 vs. 70.5 mm). A rate of 160 kg ha−1 of N (both mineral and organic) determined the optimal response for both grain yield and quality. Finally, soil and foliar application of S may help to contain the large yield and quality gap that still exists between mineral and organic fertilization of durum wheat.

Physicochemical Analysis, Electrophoretic Characterization and Verifica-tion of the Protein Fractions Responsible for Celiac Disease of Wheat Varieties Imported and Grown in Western Algeria

Celiac disease is an inflammatory enteropathy induced by ingestion of wheat proteins. This study aims to verify the protein quality of wheat varieties that are either grown in or imported into Western Algeria, by carrying out physi-cochemical and electrophoretic characterisations of the gluten proteins. We carry out physicochemical analysis of thirty-four samples of durum and bread wheat, with regard to gluten proteins. The quality of gluten was ap-preciated by Zeleny volume of bread wheat and the SDS sedimentation test for durum wheat. Meanwhile, we also characterized glutenins and gliadins into thirteen cereal varieties by monodimensional electrophoresis on SDS-PAGE and Acid-PAGE respectively. The results showed that gluten levels ranges varied from 26.82±3.99% to 56.1±1.43%. The values of the total pro-tein content had the range of 11.35±0.42% to 20.57±0.98%. The varieties studied had Zeleny values between 7.79±1.45 mL to 40.07±2.96 mL for bread wheat, and the SDS sedimentation volume ranged from 24.5±0.70 mL to 51.25±2.47 mL for durum varieties. The analysis of the glutenin and gliadin composition of the wheat varieties by electrophoresis showed the existence of α- and ω-gliadins subunits, responsible for celiac disease. Furthermore, the results revealed the presence of gliadin subunits "γ-45" and glutenins "GS-LMW Type2" related to the good quality of gluten in some varieties of wheat. As a result, we can conclude that the wheat consumed in Western Algeria has a good quality of storage proteins. Therefore, it is far from being responsible for the decrease of celiac disease in this region.

Evaluation of end use quality and root traits in wheat cultivars associated with 1RS.1BL translocation

1RS.1BL translocation in wheat, exploited for its multiple disease resistance (Lr26, Yr9, Sr31 and Pm8), has maintained significance due to its agronomical advantages. However, this translocation exhibits serious defects in dough quality due to the presence of Sec-1 loci on 1RS arm. In the present investigation micro SDS sedimentation test (MST), high molecular weight glutenin subunits (HMWGS) and bread making analysis of 26 genotypes were studied along with their root phenotyping in the field and under hydroponic culture system. The MST values showed that genotypes having Sec-1 loci had low MST values but in the presence of Glu-D1 (5 + 10) with Glu-B1 (7 + 9) and (7 + 8) they had high MST values, thus overcoming the negative effects of secalin on dough quality. The loaf volume showed positive correlation with MST values of the genotypes. The translocation of 1RS arm led to higher root biomass and longer root length than Pavon 76 without 1RS. Better root traits in recombinant 1RS 44:38 and 1B + 38 than Pavon 1RS.1BL suggested the role of negative epistatic effects between different QTL regions in 1RS arm. The results suggest that it should be possible to harness the useful alleles associated with good dough quality, better root traits, high yield and stress tolerance with or without secalin.

Transfer of HMW glutenin subunits from Aegilops kotschyi to wheat through radiation hybridization.

High molecular weight glutenin subunits (HMWGS) are responsible for dough elasticity and bread making quality of bread wheat. Related wild non-progenitor species, Aegilops kotschyi possesses higher molecular weight x and y glutenin subunits than the bread wheat cultivars. A wheat-Aegilops substitution line with 1U chromosome was used for the transfer of (HMWGS) of 1U to wheat by using pollen radiation hybridization approach. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiling showed different patterns of allelic variations with either the presence or absence of HMWGS, Glu-1A (1, null), Glu-1B (7, 7+8, 17+18) and Glu-1D (5+10, 2+12, null). The pollen irradiated wheat-Aegilops derivatives, B-56-1-4-2, B-56-1-4-3, B-14-1 and B-14-2 with Glu1Ux and 1Uy and absence or presence of some Glu-1A and Glu-1B HMWGS showed high micro SDS sedimentation test (MST) values while B-16-1 and B-16-2 had moderate MST values and high protein content. However, B-58-3 with transfer of Glu-1Ux+1Uy for Glu-1D showed very low MST values indicating that Glu-1Ux+1Uy enhance MST value only in the presence of Glu1D HMWGS. The transfer/substitution of alien HMW-GS for Glu-1A and or Glu-1B loci only can lead to improved bread making quality of wheat.

Seleção de genótipos de trigo para rendimento de grãos e qualidade de panificação em ensaios multiambientes

O objetivo deste estudo foi selecionar linhagens de trigo para qualidade de panificação e para rendimento de grãos (RG), em ensaios multiambientes, e identificar ambientes de teste ideais para a seleção. Foram avaliados 39 genótipos de trigo, sendo 18 linhagens e nove cultivares testemunhas, em 2010, e 11 linhagens e quatro cultivares testemunhas, em 2011, no Estado do Paraná. Algumas linhagens e locais não foram repetidos entre os dois anos. O delineamento experimental utilizado foi o de blocos casualizados, com três repetições. A metodologia, em gráfico biplot GGE (Genotype and Genotype-by-Environment), foi utilizada para a avaliação de genótipos e ambientes de teste. Na safra 2010, os locais de Nova Fátima, Pitangueiras e Ventania foram discriminantes (maximizaram a expressão do RG e diferenciação entre genótipos) e representativos do conjunto de ambientes avaliados. Em 2011, Rolândia e Astorga destacaram-se como ambientes ideais para seleção simultânea para RG e qualidade de panificação. As linhagens BIO-08528 e BIO-08228 foram classificadas como genótipos ideais para o RG e a concentração proteica dos grãos (CPG), respectivamente. Na safra 2011, as linhagens BIO-10161 e BIO-10141 foram superiores para RG e para qualidade de panificação, respectivamente. O teste de sedimentação SDS e a CPG correlacionaram-se entre si (r = 0,61**) e foram moderadamente associados com a força de glúten (r = 0,49** e 0,74**), indicando que podem ser utilizados na seleção indireta para qualidade de panificação.

Durum wheat (Triticum durum Desf.) Mediterranean landraces as sources of variability for allelic combinations at Glu-1/Glu-3 loci affecting gluten strength and pasta cooking quality

With the aim of identifying durum wheat landraces (LR) with a potential use in breeding programs for gluten strength enhancement, the allelic combinations present at five glutenin loci were determined in a collection of 155 LR from 21 Mediterranean countries. A set of 18 modern cultivars (MC) was used for comparison. Gluten strength was determined by SDS-sedimentation test on grain samples from field experiments conducted during 3 years. A total number of 131 different allelic/banding pattern combinations were found. Taking together high (HMW-) and low (LMW-) molecular weight glutenin subunit loci resulted in 126 combinations in LR, but only nine in MC, which are characterized for having strong gluten. Two LMW-2 type models were identified in the collection and LMW-1 types were absent. LMW-2 was present in 78 % of MC, including the only three with outstanding gluten strength (Ocotillo, Claudio and Meridiano), while 14 % of the LR had LMW-2 and 6 % LMW-2−. In the LR a known combination LMW-2 (aaa) and three new ones had a positive effect on the gluten strength. LMW-2 models were found in high frequency in LR from Italy and the three Maghreb countries; from medium to low frequencies in genotypes from Turkey, Jordan, Lebanon, Portugal and Spain, and were absent in the remaining countries. The large variability found in LR proved their potential value in breeding to broaden the genetic basis of gluten quality improvement. Genotypes interesting for breeding purposes are identified.

Generation mean analysis of gluten strength in bread wheat (Triticum aestivum): An effective utilization of micro-sedimentation test in early generation progenies

Better bread-making quality is one of the most important targets in the quality improvement programmes of wheat (Triticum aestivum L.). Gluten strength is a major indicator of bread making quality and is measured by various methods such as the SDS-sedimentation test. However, the nature of gene action for gluten strength has not been studied so far. In the present study, generation mean analysis was undertaken to estimate the nature and magnitude of gene effects for gluten strength in two sets of crosses involving contrasting parents using a less known microsedimentation test. Scaling test indicated the involvement of epistasis on the expression of the trait and inadequacy of additive-dominance model. Therefore, both six and five parameter models were used to understand the nature and direction of gene action further. Similar types of gene-action for gluten strength were recorded, albeit with some differences in the direction and magnitude of the effects, in the two sets of crosses. Among the different epistatic components, dominance × dominance effect had the maximum contribution and was acting in the negative direction in both the crosses. Analysis of both the cross combinations using Castle-Wright' equation for 'number of effective genes/blocks' revealed that at least one major gene block besides several minor genes could be involved for the micro-sedimentation volume.

Development and characteristics of ω-gliadin-free wheat genotypes

AbstractOmega gliadin proteins are one of the most allergenic components of wheat gluten. Proteins of the ω-5 subgroup are recognized as main allergens causing wheat dependent exercise induced anaphylaxis—the most dangerous, life-threatening IgE mediated food allergy. A set of wheat genotypes lacking all ω-gliadins has been developed by cumulating inactive gene variants in three gliadin coding loci (Gli A1, Gli B1 and Gli D1), using traditional plant breeding methods. Endosperm proteins of ω-gliadin-free genotypes were compared to a control genotype containing all ω-gliadins by A-PAGE, SDS-PAGE and RP-HPLC. A considerable decrease (about 30 %) of gliadin immunoreactivity as a consequence of ω-gliadin elimination was demonstrated by ELISA, using sera of ten patients allergic to gluten. Preliminary evaluation of the technological properties of the ω-gliadin-free genotype by the SDS sedimentation test suggests that elimination of all ω-gliadins may also significantly improve wheat bread making quality.

Allelic variation of HMW glutenin subunits of Ethiopian bread wheat cultivars and their quality

High molecular weight glutenins are often effective in identifying wheat (Triticum aestivum) genotypes with good baking quality. The high molecular weight glutenin subunit composition of Ethiopian cultivars and advanced lines was investigated to determine their influence on quality. Three alleles at Glu-A1, five at Glu-B1 and two at Glu-D1 and eleven different banding patterns were identified. Few cultivars had biotypes at Glu-A1 and Glu-D1 loci. There were highly significant differences between genotypes and banding patterns for the SDS-sedimentation test, mixograph development time, alveograph strength and loaf volume; but not for protein content. The frequency of subunits 5+10 among genotypes was 73%. The accumulation of high scoring alleles in our germplasm was without deliberate selection pressure towards high Glu-1 scoring alleles during breeding. Introductions from CIMMYT are widely used and such materials might have gone through selection and accumulation of such alleles at CIMMYT. Most of the studied materials had the required subunits of high quality scores and better values of the quality traits than originally thought. Therefore, the concern about poor baking quality is unlikely to be due to Glu-1 allelic variations alone.Key Words: Allelic variation, grain quality, HMW glutenins

Application of gel-protein analysis compared to conventional quality tests in characterisation of Iranian wheat cultivars

Application of glutenin macro-polymer (GMP) gel analysis compared to conventional wheat quality indicators such as total protein content, Zeleny, and SDS sedimentation values was evaluated in quality classification of 13 Iranian wheat cultivars. The results showed no significant correlation between total protein content and breadmaking characteristics. Zeleny, SDS sedimentation and GMP tests showed significant correlation with loaf volume and bread height. GMP wet weight and small-strain deformation rheological characteristic of GMP-gel were correlated with large-strain deformation rheological properties of dough measured in Farinograph and bread quality (loaf volume and height). Significant (α < 0.01) correlation was found between rheological properties of the GMP gel and Farinograph characteristics of dough. Although GMP wet weight is regarded as a predictive measure for breadmaking quality of wheat, in the light of the results of this rather small sample set we did not find significant correlation betw...

Effect of temperature variation during grain filling on wheat gluten resistance

The objective was to investigate effects of natural variation in temperature during grain filling on wheat ( Triticum aestivum L) gluten quality. Seventeen field trials with four different varieties were conducted during the years 2005–2008. Temperature records were obtained from automatic weather stations located near the field trial sites. The period from heading to yellow ripeness was divided into 20 sub-phases of equal thermal time units, and a last sub-phase comprising the seven days after yellow ripeness. Partial Least Squares Regression was used to relate the temperature records of the different sub-phases to gluten quality analysed by the Kieffer Extensibility test and the SDS sedimentation test. A large temperature variation during grain filling was recorded between different seasons, and between locations within season. The latter was mainly caused by variation in sowing time, giving different courses of temperature during grain filling. Major variation in gluten resistance was observed, ranging from Rmax of 0.13 to 1.12 N within a genotype. A higher mean temperature from heading to approximately midway in the grain filling period was positively related to gluten quality. A weaker gluten resistance was observed when the diurnal mean temperature in these periods dropped below 18 °C.

Genotype x Environment interaction for quality traits in durum wheat cultivars adapted to different environments

The quality traits of durum wheat are important for the utilization by the industries. These traits may be influenced by genotype and interaction of genotype and environment (GxE). To evaluate the effects of genotype, environment and genotype x environment interaction on quality traits such as vitreousness, SDS sedimentation test, yellow pigment index, protein content and test weight, twelve Moroccan durum wheat cultivars representing a range of agronomic adaptation were tested in five locations representing a range of environments in three growing seasons. The results indicated significant effects of genotype, environment and GxE for all the quality traits. The extent of these effects differed; for SDS sedimentation volumes, yellow pigment and test weight, the component of variation due to genotype was larger than due to the environment, indicating the greater influence of genotypes on these traits. However, for vitreousness and protein content, the effect of environment was higher than the effect due to genotypes. Thus, these traits are controlled greatly by environmental effects than genetics. The variation due to GxE was higher than that of genotype for vitreousness and test weight, indicating high GxE interaction effect and less genotypic stability for these traits. For protein content, where the environmental effect was greater than that of genotype and GxE effect, multiple environmental trials are necessary in order to determine protein content of a cultivar. For other traits, preliminary evaluations can be done in one environment and good performing ones can be selected for multiple environmental trials.