Specific Glu‐D1ƒ Allele Frequency of Japanese Common Wheat Compared with Distribution of Glu‐1 Alleles in Chinese Wheat

The quality of wheat (Triticum aestivum L.) grain favored in breadmaking is strongly affected by components of seed storage protein, particularly high molecular weight glutenin subunits (HMW‐GS). The HMW‐GS 2.2 controlled by the Glu‐D1ƒ allele is frequently found in Japanese cultivars and landraces. In the investigation into the factors affecting the distribution of the allele, the available data on HMW‐GS of common wheats from Japan were analyzed and compared with the data for intensity of winter habit and wheat flour hardness. We show that the main factors affecting the Glu‐D1ƒ allele frequency in Japanese wheat were the intensity of natural selection for winter habit and artificial selection for flour hardness. According to a study of the worldwide distribution of Glu‐1 alleles, the Glu‐D1ƒ allele is rare. However, Glu‐D1ƒ allele was the most common Japanese wheat seed storage protein allele. It is well known that Chinese wheat contributed to Japanese landraces, and Japanese landraces contributed to modern cultivars from Japan. However, common Japanese and Chinese wheats differ in the frequencies of Glu‐D1ƒ allele. These results may be explained either by the founder effect or by a selective bottleneck in Japanese common wheat genetic resources.     

Breadmaking Quality of Selected Durum Wheat Genotypes and Its Relationship with High Molecular Weight Glutenin Subunits Allelic Variation and Gluten Protein Polymeric Composition

Twenty‐seven durum wheat genotypes originating from different geographical areas, all expressing LMW‐2 at Glu‐B3, and five bread wheats were evaluated for flour mixing properties, dough physical characteristics, and baking performance. Gluten polymeric composition was studied using size‐exclusion HPLC of unreduced flour protein extracts. As a group, durum wheats had poorer baking quality than bread wheats in spite of higher protein and total polymer concentrations. Durum wheats exhibited weaker gluten characteristics, which could generally be attributed to a reduced proportion of SDS‐unextractable polymer, and produced less extensible doughs than did bread wheats. However, substantial variation in breadmaking quality attributes was observed among durum genotypes. Better baking performance was generally associated with greater dough extensibility and protein content, but not with gluten strength related parameters. Extensibility did not correlate with gluten strength or SEHPLC parameters. Genotypes expressing high molecular weight glutenin subunits (HMW‐GS) 6+8 exhibited better overall breadmaking quality compared with those expressing HMW‐GS 7+8 or 20. Whereas differences between genotypes expressing HMW‐GS 6+8 and those carrying HMW‐GS 7+8 could only be attributed to variations in extensibility, the generally inferior baking performance of the HMW‐GS 20 group relative to the HMW‐GS 6+8 group could be attributed to both weaker and less extensible gluten characteristics.     

Relationship Between the Qualitative and Quantitative Compositions of Gluten Protein Types and Technological Properties of Synthetic Hexaploid Wheat Derived from Triticum durum and Aegilops tauschii

The contribution of the diploid wheat species Aegilops tauschii (Coss.) Schmall to the technological properties of bread wheat (Triticum aestivum L.) was previously studied by the investigation of synthetic hexaploids derived from tetraploid durum wheat (T. turgidum L.) and three diploid Ae. tauschii lines. The results indicated that bread volume, gluten index, SDS‐sedimentation volume, and maximum resistance of gluten were significantly influenced by the Ae. tauschii lines. To determine the relationship between technological properties and qualitative and quantitative compositions of gluten proteins, the flours of parental and synthetic lines were extracted using a modified Osborne fractionation. Gliadin and glutenin fractions were then characterized by reversed‐phase (RP) HPLC on C₈ silica gel. The HPLC patterns revealed typical differences between synthetic and parental lines. The gliadin patterns of three synthetic lines and the glutenin patterns of two synthetic lines were more similar to that of the diploid Ae. tauschii parents involved in the hybrids. In the glutenin pattern of one synthetic line, characteristics from both Ae. tauschii and the durum wheat parents were observed. The amount of total gliadin and gliadin types of the synthetic lines was mostly intermediate between those of the durum and Ae. tauschii parents. The amounts of total glutenin and glutenin types (HMW and LMW subunits) of the synthetic lines were generally higher than those of the parental lines, and the ratio of gliadins to glutenins was significantly decreased. High positive correlations were found between the amount of total glutenins, HMW, and LMW subunits and bread volume, maximum resistance and extension area of gluten, and SDS‐sedimentation volume. The ratio of gliadins to glutenin subunits had a strong negative influence on these properties. The protein content of the flours and the amount of total gluten proteins were not correlated with any of the technological properties. Results on the relationship between biochemical characteristics and the breadmaking properties indicated that wheat prebreeding would benefit from studies on protein types and quantification in the choice of parents. In addition, the potential of the diploid Ae. tauschii for improvement of breadmaking quality should be further exploited.     

Protein and Quality Characterization of Triticale Translocation Lines in Breadmaking

Introduction of high molecular weight glutenin subunits (HMW‐GS) from the Glu‐D1d locus of wheat into triticale restores the genetic constitution of high molecular weight glutenin loci to that of wheat and subsequently improves the breadmaking quality of triticale. One means of achieving such restoration of the genetic constitution is through the use of translocation lines. The aim of this study was to evaluate and compare the performance of translocations 1A.1D and 1R.1D with HMW‐GS 5+10 and 2+12 in terms of physical dough tests and baking quality using four different sets of triticale lines, GDS7, Trim, Rhino, and Rigel. In general, significantly lower milling quality (flour yield), very low mixing times with lower loaf volume were typical of all the triticales studied except 1A.1D 5+10 lines, when compared to hard wheat flour (Pegaso). Among the lines studied, significantly higher loaf volume, mixograph dough development time (MDDT), and maximum resistance to extension (R_max) were observed with 1A.1D 5+10 lines indicating that translocation of the Glu‐D1d allele with HMW‐GS 5+10 was beneficial in terms of improving the quality attributes. Although pure triticale flour from these lines did not possess the functional characteristics for good quality bread, the translocation 1A.1D that contains HMW glutenin subunits 5+10 showed significant improvement in quality characteristics, and could reasonably be expected to yield commercially satisfactory bread loaves when combined with bread wheat flour. Significantly higher UPP, R_max, and MDDT values along with a lower gliadin‐to‐glutenin ratio in 1A.1D 5+10 of GDS7 and Rigel sets indicate that the molecular weight distribution was shifted to higher molecular weights, resulting in greater dough strength associated with 5+10 subunits.     

Quality and Agronomic Effects of Three High‐Molecular‐Weight Glutenin Subunit Transgenic Events in Winter Wheat

Quality and agronomic effects of three transgenic high molecular weight glutenin subunit (HMW‐GS) events were characterized in advanced‐generation breeding lines of hard winter wheat (Triticum aestivum L.) in three Nebraska crop years. Two of the transgenic events studied, Dy10‐E and B52a‐6, overexpress HMW‐GS 1Dy10, while the third event, Dx5 +Dy10‐H, overexpresses HMW‐GS 1Dx5 and, to a much lesser extent, 1Dy10. In addition, novel proteins possessing solubility characteristics defined as HMW‐GS were present in Dx5+Dy10‐H and B52a‐6. Average grain yield of lines derived from the three transgenic events was statistically lower than that of a group of control cultivars and advanced breeding lines, but not lower than the mean values of respective nontransgenic siblings. Grain hardness was influenced by one of the events. Dx5+Dy10‐H produced harder kernels than controls, its nontransgenic siblings, and the two additional transgenic events. All three events produced doughs with unusual mixing properties, although not likely to be directly useful in commercial applications. As a consequence, loaf volumes were depressed to variable degrees by the three events. The results indicated that over‐expression of HMW‐GS could eventually lead to improved breadmaking quality by optimizing the level of overexpression or by development and characterization of additional events.     

Synergistic and Additive Effects of Three High Molecular Weight Glutenin Subunit Loci. II. Effects on Wheat Dough Functionality and End‐Use Quality

Understanding the relationship between basic and applied rheological parameters and the contribution of wheat flour protein content and composition in defining these parameters requires information on the roles of individual flour protein components. The high molecular weight glutenin subunit (HMW‐GS) proteins are major contributors to dough strength and stability. This study focused on eight homozygous wheat lines derived from the bread wheat cvs. Olympic and Gabo with systematic deletions at each of three HMW‐GS encoding gene loci, Glu‐A1, Glu‐B1, and Glu‐D1. Flour protein levels were adjusted to a constant 9% by adding starch. Functionality of the flours was characterized by small‐scale methods (2‐g mixograph, microextension tester). End‐use quality was evaluated by 2‐g microbaking and 10‐g noodle‐making procedures. In this sample set, the Glu‐D1 HMW‐GS (5+10) made a significantly larger contribution to dough properties than HMW‐GS coded by Glu‐B1 (17+18), while subunit 1 coded by Glu‐A1 made the smallest contribution to functionality. These differences remained after removing variations in glutenin‐to‐gliadin ratio. Correlations showed that both basic rheological characteristics and protein size distributions of these flours were good predictors of several applied rheological and end‐use quality tests.     

Synergistic and Additive Effects of Three High Molecular Weight Glutenin Subunit Loci. I. Effects on Wheat Dough Rheology

The high molecular weight glutenin subunits (HMW‐GS) play an important role in governing the functional properties of wheat dough. To understand the role of HMW‐GS in defining the basic and applied rheological parameters and end‐use quality of wheat dough, it is essential to conduct a systematic study where the effect of different HMW‐GS are determined. This study focuses on the effect of HMW‐GS on basic rheological properties. Eight wheat lines derived from cvs. Olympic and Gabo were used in this study. One line contained HMW‐GS coded by all three loci, three lines were each null at one of the loci, three lines were null at two of the loci and one line null at all three loci. The flour protein level of all samples was adjusted to a constant 9% by adding starch. In another set of experiments, in addition to the flour protein content being held at 9%, the glutenin‐to‐gliadin ratio was maintained at 0.62 by adding gliadin. Rheological properties such as elongational, dynamic, and shear viscometric properties were determined. The presence of Glu‐D1 subunits (5+10) made a significantly larger contribution to dough properties than those encoded by Glu‐B1 (17+18), while subunit 1, encoded by Glu‐A1, made the least contribution to functionality. Results also confirmed that HMW‐GS contributed to strength and stability of dough.     

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.     

Influence of High Molecular Weight Glutenins on Viscoelastic Properties of Intact Wheat Kernel and Relation to Functional Properties of Wheat Dough

High and low molecular weight glutenin subunits (HMW‐GS and LMW‐GS, respectively) are the main factors determining the viscoelastic properties of wheat dough. The mechanical and viscoelastic properties of 29 samples of wheat kernels differing in HMW‐GS were evaluated with load‐compression tests. Samples were grouped by genotypes differing in HMW‐GS composition (allelic variants: Glu‐A1: null, 1, 2*; Glu‐B1: 7, 7+8, 7+9, 13+16, and 17+18; Glu‐D1: 5+10, 2+12). Groups representing Glu‐A1 1 and 2*; Glu‐B1 7, 7+9 and 17+18; and Glu‐D1 5+10 generally possessed hard grain and showed the largest kernel elasticity values, while those representing subunits Glu‐A1 null; Glu‐B1 7+8; and Glu‐D1 2+12 had soft kernels and showed lower elastic work values. Genotypes possessing HMW‐GS 1, 17+18 and 5+10 gave large SDS‐sedimentation values and better dough viscoelastic properties than those with allelels: null, 7+8, and 2+12. Kernel hardness showed significant correlation with the dough‐strength‐related parameters: SDS‐sedimentation; dough mixing time; and the alveographic parameters, W and P. There was a negative correlation between kernel plastic work and dough mixing time and the dough tenacity/extensibility parameters, P/L. The significant relationship between sedimentation tests and kernel elastic work seems to indicate that elastic work is related to genotype (protein composition). The general tendency was that higher values in kernel elastic work and size corresponded to better dough rheological quality. Mechanical properties of the kernel were significantly related to the elastic behavior measured in a single wheat kernel. The use of the compression test on individual kernels is easy, rapid and nondestructive and therefore seems to show potential use as a rapid tool in breeding to improve wheat quality.     

Effect of Climate Change on Wheat Quality and HMW Glutenin Subunit Composition in the Pannonian Plain

The primary goal of this study is to improve our understanding of the extent of influence of climatic factors in Serbia and high‐molecular‐weight glutenin subunit (HMW‐GS) composition upon wheat end‐use quality. In‐depth analyses were performed on four bread wheat cultivars that are the most common in agricultural practice in Serbia. Total glutenin content showed significant difference between the production years, in opposition to gliadins. Cluster analysis of different percentages of glutenin and gliadin subunit molecular weight ranges (<40,000, 40,000–80,000, 81,000–120,000, and >120,000) indicated that the year of production and the cultivar did not have a significant effect on the percentage ranges for glutenins. However, they had a considerable impact on the percentage ranges for gliadins. Production year and the interaction of year and cultivar had the strongest influences on the percentage of SDS‐unextractable polymeric proteins. A synergistic effect of the HMW‐GS composition and climatic conditions revealed that all eight samples with HMW‐GS composition 2*, 5 + 10, 7 + 9 along with the highest Glu 1 score of 9 (out of a maximum of 10) produced in the year 2011 belonged to two clusters with the best wheat end‐use quality. Furthermore, the climate conditions in 2011 made it possible for the wheat cultivars with HMW‐GS composition –, 2 + 12, 7 + 9 to possess similar qualities as cultivars with HMW‐GS composition 2*, 5 + 10, 7 + 9 produced in 2012.     

Protein Allelic Composition,Dough Rheology,and Baking Characteristics of Flour Mill Streams from Wheat Cultivars with Known and Varied Baking Qualities

Flour mill streams obtained by milling grain of 10 bread wheat cultivars grown in the Skopje region of Macedonia were analyzed for rheological and breadmaking quality characteristics and for composition of gliadins and HMW‐GS. The objective of this study was to examine the relationships between the composition of gluten proteins and breadmaking quality, as well as to determine the importance of gluten proteins for technological quality of flour mill streams. The grain was milled in an experimental mill according to a standardized milling procedure, with three break and three reduction passages. The addition of two vibratory finishers in the milling scheme enabled better separation of bran. A small‐scale baking method for evaluation of the breadmaking properties was developed, and electrophoretic methods including acid‐PAGE and SDS‐PAGE were used to determine the composition of the gluten proteins. There were significant differences in the degree of dough softening of individual and total flour fractions of the flour mill streams for cultivars with different alleles from six loci, for farinograph water absorption from seven loci, and for bread loaf volume and crumb quality score from six loci. The Glu‐1 quality scores for the wheat cultivars investigated were 3–9 and proved to be a useful indicator of breadmaking quality. The novel feature of the investigation related to the breadmaking potential of the flour mill streams compared with straight‐run flours.     

Expression,Purification, and Functional Analysis of Three Low‐Molecular‐Weight Glutenin Subunits from Wheat Cultivar Cheyenne

Glutenins, which form the network of gluten protein, are of great importance for the quality of flour products. Glutenins can be divided into HMW and LMW subunits according to molecular weight. Three genes for LMW glutenin subunits (LMW‐GS), named lmw‐cnd1, lmw‐cnd2, and lmw‐cnd3 with open reading frames of 1,053, 903, and 969 bp, respectively, were cloned from wheat cultivar Cheyenne. Heterologous expression vectors of the three LMW‐GS were constructed, and the recombinant proteins LMW‐CND1, LMW‐CND2, and LMW‐CND3 were overexpressed in Escherichia coli. After cell disruption with ultrasound, target proteins of high purity were obtained by using Ni²⁺ affinity chromatography. Farinograph and TAPlus measurements were used to investigate the effects of the three LMW‐GS on the characteristics of flour and dough. The results showed that the addition of each LMW‐GS can lead to an increase in the elasticity of the dough. Moreover, LMW‐CND2 and LMW‐CND3 promoted the strength of the dough. All three LMW‐GS caused a decrease of hardness and increase of springiness and cohesiveness of dough according to texture profiling results. Consequently, all three LMW‐GS have positive effects on the processing characteristics of dough and can improve bread quality to different extents.     

Effect of the Molecular Weight Distribution of Glutenin Protein from an Extra‐Strong Wheat Flour on Rheological and Breadmaking Properties Through Reconstitution Studies

Ten glutenin fractions were separated by sequential extraction of wheat gluten protein with dilute hydrochloric acid from defatted glutenin‐rich wheat gluten of the Canadian hard red spring wheat (HRSW) cultivar Glenlea. The molecular weight distribution (MWD) of 10 different soluble glutenin fractions was examined by multistacking SDS‐PAGE under nonreduced conditions. Also, the subunit composition of the different glutenin fractions was determined by SDS‐PAGE under reduced conditions. The MWD of the fractions (especially HMW glutenins) varied from fraction to fraction. From early to later fractions, the MWD shifted from low to high. The early extracted fractions contained more LMW glutenin subunits (LMW‐GS) and less HMW glutenin subunits (HMW‐GS). The later extracted fractions and the residue fraction contained much more HMW‐GS (2*, 5, and 7 subunits) than the early extracted fractions. The trend in the amounts of 2*, 5, and 7 subunits in each fraction from low to high matched the extraction solvent sequence containing from lower to higher levels of HCl. The influence of glutenin protein fractions from the extra‐strong mixing cultivar, Glenlea, on the breadmaking quality of the weak HRSW, McVey, was assessed by enriching (by 1%) the McVey base flour with isolated glutenin protein fractions from Glenlea. The mixograph peak development times and loaf volumes of enriched flour were measured in an optimized baking test. The results indicated that the higher content in Glenlea glutenin of HMW‐GS with higher molecular weight, such as 2*, 5, and 7, seem to be the critical factor responsible for the strong mixing properties of Glenlea. Our results confirmed that subunit 7 occurred in the highest quantity of all the HMW‐GS. Therefore, it seems that the greater the content of larger molecular weight glutenin subunits, the larger the glutenin polymers and the stronger the flour.     

Rapid Identification of HMW Glutenin Subunits from Different Hexaploid Wheat Species by Acidic Capillary Electrophoresis

High molecular weight glutenin subunits (HMW‐GS) from three hexaploid wheat species (AABBDD, 2n=6x=42, Triticum aestivum L., T. spelta L., and T. compactum L.) were separated and identified by acidic capillary electrophoresis (A‐CE) with phosphate‐glycine buffer (pH 2.5) in uncoated fused‐silica capillaries (50 μm, i.d. × 25.5 cm) at 12.5 kV and 40°C. The rapid separations (<15 min) of HMW‐GS with good repeatability (RSD < 2%) were obtained using a fast capillary rising protocol. All 17 HMW‐GS analyzed could be well separated and their relative migration orders were ranked. In particular, the good quality subunit pair 5+10 could be differentiated from poor quality subunit pair 2+12. In addition, the other three allelic pairs of 13+16, 17+18, and 7+8 subunits that were considered to have positive effects on dough properties, as well as three pairs of novel subunits 13+22*, 13*+19*, and 6.1+22.1 detected from spelt and club wheat, can also be readily separated and identified. An additional protein subunit presented in Chinese bread wheat cultivar Jing 411 and club wheat TRI 4445/75, respectively, was detected by both A‐CE and 2‐D gel electrophoresis (A‐PAGE × SDS‐PAGE), for which further identification is needed.     

Accumulation of High‐Molecular‐Weight Glutenin Subunits in Superior and Inferior Grains of a Winter Wheat,Yangmai 158

The difference in accumulation of high‐molecular‐weight glutenin subunits (HMW‐GS) in superior (basal) and inferior (distal) grains results in the nonuniformity of grain quality in a winter wheat (Triticum aestivum L. ‘Yangmai 158’). The HMW‐GS accumulation and glutenin macropolymer (GMP) content were studied in superior and inferior grains during the grain‐filling period. Compared with inferior grains, HMW‐GS was formed earlier and total accumulation amount was higher in superior grains. The total HMW‐GS content was higher in superior grain than inferior grain, except at maturity. For individual HMW‐GS types, the accumulation and content of subunit 7 were the highest, followed by subunit 12, and those of subunit 8 were the lowest, followed by subunit 2 in superior grain. In contrast, the accumulation and content of subunit 7 at maturity were significantly higher than subunit 8 but similar between subunit 2 and subunit 12 in inferior grain. Moreover, the accumulation of subunit 7 and 12 in superior grain was significantly higher than in inferior grain. However, compared with the inferior grain, the GMP accumulation was higher but content was lower in superior grain at maturity.     

Comparison of Small and Large Deformation Rheological Properties of Wheat Dough and Gluten

The rheological properties of dough and gluten are important for end‐use quality of flour but there is a lack of knowledge of the relationships between fundamental and empirical tests and how they relate to flour composition and gluten quality. Dough and gluten from six breadmaking wheat qualities were subjected to a range of rheological tests. Fundamental (small‐deformation) rheological characterizations (dynamic oscillatory shear and creep recovery) were performed on gluten to avoid the nonlinear influence of the starch component, whereas large deformation tests were conducted on both dough and gluten. A number of variables from the various curves were considered and subjected to a principal component analysis (PCA) to get an overview of relationships between the various variables. The first component represented variability in protein quality, associated with elasticity and tenacity in large deformation (large positive loadings for resistance to extension and initial slope of dough and gluten extension curves recorded by the SMS/Kieffer dough and gluten extensibility rig, and the tenacity and strain hardening index of dough measured by the Dobraszczyk/Roberts dough inflation system), the elastic character of the hydrated gluten proteins (large positive loading for elastic modulus [G′], large negative loadings for tan δ and steady state compliance [J_e⁰]), the presence of high molecular weight glutenin subunits (HMW‐GS) 5+10 vs. 2+12, and a size distribution of glutenin polymers shifted toward the high‐end range. The second principal component was associated with flour protein content. Certain rheological data were influenced by protein content in addition to protein quality (area under dough extension curves and dough inflation curves [W]). The approach made it possible to bridge the gap between fundamental rheological properties, empirical measurements of physical properties, protein composition, and size distribution. The interpretation of this study gave indications of the molecular basis for differences in breadmaking performance.     

Relationships Between Gluten Rheological Properties and Hearth Loaf Characteristics

The rheological properties of fresh gluten in small amplitude oscillation in shear (SAOS) and creep recovery after short application of stress was related to the hearth breadbaking performance of wheat flours using the multivariate statistics partial least squares (PLS) regression. The picture was completed by dough mixing and extensional properties, flour protein size distribution determined by SE‐HPLC, and high molecular weight glutenin subunit (HMW‐GS) composition. The sample set comprised 20 wheat cultivars grown at two different levels of nitrogen fertilizer in one location. Flours yielding stiffer and more elastic glutens, with higher elastic and viscous moduli (G′ and G″) and lower tan δ values in SAOS, gave doughs that were better able to retain their shape during proving and baking, resulting in breads of high form ratios. Creep recovery measurements after short application of stress showed that glutens from flours of good breadmaking quality had high relative elastic recovery. The nitrogen fertilizer level affected the protein size distribution by an increase in monomeric proteins (gliadins), which gave glutens of higher tan δ and flatter bread loaves (lower form ratio).     

Composition of HMW and LMW Glutenin Subunits and Their Effects on Dough Properties,Pan Bread,and Noodle Quality of Chinese Bread Wheats

Knowledge of composition of high molecular weight glutenin subunits (HMW‐GS) and low molecular weight glutenin subunits (LMW‐GS) and their associations with pan bread and noodle quality will contribute to genetically improving processing quality of Chinese bread wheats. Two trials including a total of 158 winter and facultative cultivars and advanced lines were conducted to detect the allelic variation at Glu‐1 and Glu‐3 loci by SDS‐PAGE electrophoresis and to understand their effects on dough properties, pan bread, and dry white Chinese noodle (DWCN) quality. Results indicate that subunits/alleles 1 and null at Glu‐A1, 7+8 and 7+9 at Glu‐B1, 2+12 and 5+10 at Glu‐D1, alleles a and d at Glu‐A3, and alleles j and d at Glu‐B3 predominate in Chinese germplasm, and that 34.9% of the tested genotypes carry the 1B/1R translocation (allelic variation at Glu‐D3 was not determined because no significant effects were reported previously). Both variations at HMW‐GS and LMW‐GS/alleles and loci interactions contribute to dough properties and processing quality. For dough strength related traits such as farinograph stability and extensigraph maximum resistance and loaf volume, subunits/alleles 1, 7+8, 5+10, and Glu‐A3d are significantly better than those of their counterpart allelic variation, however, no significant difference was observed for the effects of d, b, and f at Glu‐B3 on these traits. For extensigraph extensibility, only subunits 1 and 7+8 are significantly better than their counterpart alleles, and alleles d and b at Glu‐B3 are slightly better than others. For DWCN quality, no significant difference is observed for HMW‐GS at Glu‐1, and Glu‐A3d and Glu‐B3d are slightly better than other alleles. Glu‐B3j, associated the 1B/1R translocation, has a strong negative effect on all quality traits except protein content. It is recommended that selection for subunits/alleles 1, 7+8, 5+10, and Glu‐A3d could contribute to improving gluten quality and pan bread quality. Reducing the frequency of the 1B/1R translocation will be crucial to wheat quality improvement in China.     

Baking Quality of Bread Wheat Cultivars Damaged by Nysius simulans

Wheat grain may be attacked by different insect species. Among them, some Heteroptera species (e.g., Aelia spp. and Eurygaster spp.) reduce wheat breadmaking quality; others, such as Nysius simulans , commonly extract water and nutrients from soy plants. The aim of this study was to assess the effect of N. simulans infestation on breadmaking quality of different bread wheat cultivars. Twelve wheat cultivars (damaged and undamaged by N. simulans ) were studied. Infested grain percentage varied between 51 and 78%, depending on cultivar. Protein and gluten quantity and quality were significantly reduced in damaged flours, as shown by gluten index, solvent retention capacity, and SDS sedimentation index. SDS‐PAGE from water‐extractable proteins evidenced an important proteolytic activity in damaged samples. Dough rheological properties showed a reduced dough viscoelasticity in damaged samples. Microbread specific volume changed from 3.26 cm³/g for samples made with undamaged flour to 2.77 cm³/g for bread made with damaged flour. No evidence for modification in starch properties was found. The infestation by N. simulans reduced wheat breadmaking quality in all cultivars studied, as a result of proteolytic activity occurring after dough hydration. Results suggest that the presence of N. simulans should be considered as a factor affecting wheat crops, mainly those located next to soy crop areas, which is the usual host for this insect.     

Rapid Quality Assessment of Wheat Cultivars Registered in Poland Using the 2‐g Mixograph and Multivariate Statistical Analysis

Baking and 2‐g mixograph analyses were performed for 55 cultivars (19 spring and 36 winter wheat) from various quality classes from the 2002 harvest in Poland. An instrumented 2‐g direct‐drive mixograph was used to study the mixing characteristics of the wheat cultivars. A number of parameters were extracted automatically from each mixograph trace and correlated with baking volume and flour quality parameters (protein content and high molecular weight glutenin subunit [HMW‐GS] composition by SDS‐PAGE) using multiple linear regression statistical analysis. Principal component analysis of the mixograph data discriminated between four flour quality classes, and predictions of baking volume were obtained using several selected mixograph parameters, chosen using a best subsets regression routine, giving R² values of 0.862–0.866. In particular, three new spring wheat strains (CHD 502a‐c) recently registered in Poland were highly discriminated and predicted to give high baking volume on the basis of two mixograph parameters: peak bandwidth and 10‐min bandwidth.