Glu-1 Loci Research Articles

Selection of marker systems for determining the allelic composition of high molecular glutenin loci in winter wheat

Aim. Selection of marker systems and conducting multiplex polymerase chain reactions to determine the allelic composition of the Glu-A1, Glu-B1 and Glu-D1 loci, which determine the high quality of flour in common wheat samples. Methods. Polymerase chain reaction (PCR) using specific primers for the Glu-A1, Glu-B1 and Glu-D1 loci of wheat. Results. PCR analysis was performed to detect the insertion at 43 b. p. in the MAR region, in varieties with the Glu-B1al allele, the presence of an amplicon 563 b. p. long was observed, for varieties that carry other alleles of the locus – an amplicon 520 b. p. long. The results on the Glu-D1 locus showed that for № 2, № 3, № 4, № 7, № 8, № 10, № 11, № 19, № 20, № 21 subunits (5 + 10) were identified. Conclusions. With the help of allele-specific primers, the allelic composition of loci of high molecular weight glutenins was determined in 22 lines wheat. Three alleles Glu-A1a, Glu-A1b, Glu-A1c were found in the Glu-A1 locus; in the Glu-B1 locus, only the Glu-B1al allele was detected, there are two alleles at the Glu-D1 locus: Glu-D1a and Glu-D1d (the Glu-D1a allele predominated). As a result of our research, samples of soft wheat (lines № 2, № 7, № 21) were selected, which can be attributed to genotypes with high baking quality of the flour.

Characterization of Bila Tserkva winter common wheat cultivars with respect to marker loci

Aim. We studied special features of the sample of Bila Tserkva winter common wheat cultivars with respect to storage protein loci and some disease resistance genes. Methods. To identify alleles at gliadin and high-molecular-weight glutenin loci, acid polyacrylamide gel electrophoresis and SDS-electrophoresis of grain proteins were carried out. Alleles of markers for the disease resistance genes Lr34, Tsn1, and TDF_076_2D were identified using PCR. Results. The composition and frequencies of alleles at the Gli-1, Glu-1, and Gli-A3 loci were studied in samples of Bila Tserkva cultivars released before 2011 and after 2010. For the latter group of cultivars, alleles of the disease resistance gene markers were identified. We observed a significant increase in the frequency of the allele Gli-A1x(9) and a decrease in the frequency of Gli-A1c, as well as a tendency for an increase in the frequency of Gli-A3c. In the total sample of Bila Tserkva cultivars, nonrandom associations of pairs of certain storage protein alleles were revealed. Conclusions. The group of Bila Tserkva cultivars is similar to the previously studied groups of the Central Forest Steppe of Ukraine with respect to allele set and frequencies of the main prolamin loci, but differs in the frequencies of the disease resistance genes. A special feature of the group of Bila Tserkva cultivars is a high frequency of the allele c at the minor locus Gli-A3, as well as the allele association Gli-A1x Gli-B1l Gli-A3c.

The High-Molecular-Weight Glutenin Subunits of the T. timopheevii (AuAuGG) Group.

Polyploid wheats include a group of tetraploids known as Timopheevii (AuAuGG), which are represented by two subspecies: Triticum timopheevii ssp. timopheevii (cultivated) and Triticum timopheevii ssp. araraticum (wild). The combined use of electrophoretic (SDS-PAGE) and chromatographic (RP-HPLC) techniques carried out on high-molecular-weight glutenin subunits (HMW-GSs) permitted the association of different x- and y-type subunits to the A and G genomes and the assessment of allelic variation present at corresponding loci. The results also revealed that in both subspecies, accessions are present that possess expressed y-type subunits at the Glu-A1 locus. Genes corresponding to these subunits were amplified and amplicons corresponding to x- and y-type genes associated with the A genome were detected in all accessions, including those without expressed x- and y-type subunits. The comparison with genes of polyploid wheats confirmed the structural characteristics of typical y-type genes, with the presence of seven cysteine residues and with hexapeptide and nonapeptide repeat motifs. The identification of wild and cultivated T. timopheevii with both x- and y-type glutenin subunits at the Glu-A1 and Glu-G1 loci represents a useful source for the modification of the allelic composition of HMW-GSs in cultivated wheats with the ultimate objective of improving technological properties.

GLUTENIN DIVERSITY OF FLOUR WHEAT (Triticum aestivum L.) FOR COOKIE QUALITY IN MEXICO

Glutenins are high- and low-molecular-weight proteins (HMW-G and LMW-G). They play a determining role in genetic improvement to define industrial quality in flour wheat, so understanding their variability is necessary for directing selection toward a specific quality. The objective of this research was to determine the diversity of HMW-G and LMW-G alleles of genotypes from the flour wheat breeding program of the National Institute of Forestry, Agricultural, and Livestock Research (INIFAP) useful for cookie quality. Twenty-five genotypes were used, including six Mexican cookie varieties, as well as 21 genotypes introduced from an international collection of accessions from the International Maize and Wheat Improvement Center (CIMMYT). HMW-G and LMW-G were identified based on their separation on polyacrylamide gels in the presence of sodium dodecyl sulfate. For HMW-G, the 2* variant in Glu-A1 was the most frequent variant for the trial and introduction nursery, with more than 80 %. At the Glu-B1 locus, the 7+9 and 7 variants were the most frequent, with 60 and 38.1 % in trial and nursery, respectively. For Glu-D1, the 2+12 variant was the most frequent in the trial with 64 %, and 5+10 with 85.7 % in nursery. The latter allele favors baking quality. For the Glu-A1 and Glu-D1 loci, it is necessary to introduce genotypes with null alleles or with the 2+121 variant in Glu-D1 associated with cookie quality. For the highest-frequency variants of LMW-G, c in Glu-A3, h in Glu-B3, and b in Glu-D3 are associated with baking quality. With the aforementioned, it is concluded that there is a low frequency and little variation in useful alleles of HMW-G and LMW-G for cookie quality in the introduced accessions analyzed, implying that new genetic sources that favor it should be explored.

Development of a germplasm master set covering variability of high molecular weight glutenin subunits for the GLU-A1 locus in Triticum sp.

Gluten quality is an important characteristic of wheat. Gluten is a viscoelastic protein network that is formed after hydrating and mixing wheat flour. This protein network is mainly composed of glutenins (High and Low Molecular Weight Glutenins (HMW-GS and LMW-GS, respectively)) and gliadins. HMW-GS are codified by the loci GLU-A1, GLU-B1 and GLU-D1 in common wheat. For the GLU-A1 locus, many alleles have been described and collected in the Wheat Gene Catalogue (WGC). Many of those alleles have not been compared in conjunction and it is not possible to know if the current GLU-A1 variability described is real or it is overestimated. This study has focused on collecting all the germplasm associated with GLU-A1 variability, to verify the GLU-A1 allele of each accession and if the current variability described in the WGC is real. It was possible to collect and compare by SDS-PAGE most of the germplasm described in the WGC. The identity of many alleles was confirmed while there are other cases that should be reviewed in more detail. This study contributes to the correct classification of the GLU-A1 diversity and will promote the use of different alleles in future breeding programs aiming to improve gluten quality.

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.

Genetic Diversity of HMW-GS and the Correlation of Grain Quality Traits in Bread Wheat (Triticum aestivum L.) in Hubei Province, China

High-molecular-weight glutenin subunits (HMW-GS) are an important component of total cereal proteins in wheat. It is closely related to the processing quality of flour. Here, we analyzed allelic variations at the Glu-1 locus in 163 wheat accessions from Hubei Province, China with SDS-PAGE. Among the 15 alleles detected, alleles 1, 7+8, and 2+12 were the major alleles, and 7, 6+8, and 2+10 were rare alleles. The breeding lines had higher genetic diversity than the commercial varieties. Alleles 7 and 6+8 significantly reduced the grain protein content and wet gluten content of wheat. The “1, 7+9, 5+10” and “1, 14+15, and 2+12” allelic combinations significantly increased the grain protein content, hardness index, test weight, and wet gluten content of wheat. Alleles 7+9, 14+15, and 5+10 were identified as alleles related to high wheat quality. The “1, 7, 5+10”, “1, 6+8, 5+10”, “null, 7+9, 2+12”, “1, 14+15, 2+12”, and “1, 7+9, 5+10” allelic combinations had greater effects on wheat grain quality traits. These results demonstrate the effects of HMW-GS on wheat grain quality traits and provide a reference for the genetic improvement of wheat quality.

Effects of the 1RS.1BL wheat-rye translocationon kernel and bran content of bread wheat (Triticum aestivum L.)

In this study, the effects of rye translocation on some quality properties and mineral content of whole wheat kernel and bran were investigated.The plant material consisted of 147 recombinant inbred lines (RILs) and five control cultivars, including the parent. The genotypes were grown in Turkey at two different locations for two consecutive years. In the study, lines with and without rye translocation were determined by SDS-PAGE and PCR analysis, and the glutenin subunits of the lines at Glu-A1, Glu-B1, Glu-A3 and Glu-B3 loci were also analyzed. The protein, starch, fat, ash, dry matter, acid detergent insoluble fiber (ADF), neutral detergent insoluble fiber (NDF), potassium (K), phosphorus (P) and magnesium (Mg) contents of kernels and bran of the RILs were determined. Statistically significant differences were found between the genotypes in terms of all the examined characteristics except the amount of dry matter. The RILs carrying translocation 1RS.1BLhad a higher average ADF, NDF, protein content, ash content, K, Mg, and P contents of kernels, as well as a higher average ADF, NDF, ash, and K bran contents than the RILs without thetranslocation. The bran of the RILs without thetranslocationhad higher values in terms of fat, starch, and phosphorus content. The results indicate that wheat- rye translocation1RS.1BL has a significant effect on both whole wheat kernel and bran content, and can be used to enrich the content of wheat bran.

Effects of high-molecular-weight glutenin subunit on hard-steamed bread quality.

Steamed bread (SB) is a daily food in many countries in the world, but the relationship between HMW-GS and the quality of SB remain unclear. This study investigated the effects of 12 subunit combinations on the characteristics of SB, including volume, physical properties, and sensory evaluation, combined with the microstructure and dough rheological properties. The locus effect results showed, volume and physical properties of SB were Glu-D1>Glu-B1>Glu-A1, while sensory scores Glu-B1>Glu-D1>Glu-A1. According to individual subunit effects, subunit 1 at Glu-A1 locus, 7+8 and 7+9 subunits at Glu-B1 locus, and 2+10 and 5+12 subunits at Glu-D1 locus were significantly superior to other subunits in physical indices like volume, chewiness, glueyness, and sensory scores, and were less affected by moisture. The effect of subunits combination is mainly affected by subunits, and the combination of superior subunits tends to make SB quality better. The subunit combinations (1, 7+8, 5+12), (N, 7+9, 2+10) and (1, 7+9, 5+12) had better physical properties indexes, sensory scores, dense, uniform and delicate micro-pore structure, and smaller thickness wall. The results showed that protein content, wet gluten content and stability time were the main factors affecting the volume and physical properties of SB. The protein content, wet gluten content and stability time of flour in 7+8, 7+9, 2+10 and 5+12 subunits were higher. Therefore, the quality of SB containing these subunits was found better.

Baking Quality of Organically Grown European Winter Wheat Germplasm in the South-East of Romania

Baking quality of organic winter wheat remains a significant challenge, primarily due to the usually lower grain protein concentration realized in organic agriculture. This study examined eighty-four winter wheat genotypes from Europe under organic conditions in the south-east of Romania, during two contrasting seasons. Various quality traits, i.e., grain protein content, bread volume, dough strength, breakdown and extensibility were analyzed. All examined traits exhibited significant differences among cultivars. Molecular assays, utilizing markers for Glu-A1, Glu-D1, Glu-B3g and NAM-A1 loci revealed genetic diversity within the germplasm. The study highlighted sixteen genotypes with bread volume statistically significant different from the average trial. In the organic system the Glu-A1x2* allele had positive effects on bread volume, water absorption, dough strength and extensibility. At Glu-D1, the alleles for Dx5 + Dy10 were detected in over 85% cultivars and showed positive effects on dough development time and extensibility. Another locus with positive effect on baking quality was NAM-A1. In this study the haplotype NAM-A1c had the highest frequency (51%), followed by NAM-A1d (38%) and NAM-A1a (11%). Both NAM-A1a and NAM-A1c haplotypes positively affected bread volume, water absorption, dough strength and extensibility. The Glu-B3g allele had a positive effect on development time. However, these genes could not explain the whole variation of quality parameters, as some of the best cultivars had unfavorable alleles while other cultivars carrying positive alleles had low quality. Obviously, other factors strongly influenced the quality parameters in organic agriculture, and further research is needed to understand their nature. Our results suggest the potential for achieving improved breadmaking quality, under organic conditions, by exploring genetic possibilities. However, combining suitable breadmaking quality with high yield will remain a challenge.

Assessing Payne score accuracy through a bread wheat multi-genotype and multi-environment set from CIMMYT

The Payne score is a prevalent strategy for assessing wheat quality by considering the distinct contributions of specific high-molecular-weight glutenin subunits. Despite its extensive use, the limited germplasm used in its development (84 British cultivars from the early 1980s) may limit its accuracy when is applied to other type of germplasm. Here we tested the Payne score accuracy and related scales using an extensive dataset. The precision of the scale is higher for Glu-A1 and Glu-D1 loci, particularly when predicting dough strength, and loaf volume. However, for dough extensibility, the accuracy decreased. For Glu-B1 it could discriminate differences to some extent, but higher scores did not always correspond to higher quality values, and vice versa. When the total Payne score was evaluated, the most pronounced degree of differentiation between scale values was observed for gluten strength related traits. When analyzing the total Payne score for various haplotypes, higher values for gluten strength, and loaf volume generally corresponded to higher Payne scores; however, some samples with low values were ranked with the highest scores and vice versa. Our findings suggest that there is a probability of selecting cultivars with high Payne scores that do not match the desired quality.

Study of Baking Quality and Determination of High Molecular Weight Glutenin Subunits (HMW-GS) of Local and Introduced Wheat Varieties

The baking qualities of 36 varieties of wheat are considered. Storage proteins — high molecular weight glutenin subunits (HMW-GS) — were studied. Electropherograms were processed in the GelPro Analyzer 4.0 computer program. The molecular weight of glutenin subunits was determined according to the method of G. Galili, M. G. Feldman using a marker variety. The quality of glutenin was assessed in points according to the method of O. Lukov. The bread was baked using the straight method, in accordance with the generally accepted method of laboratory baking; the fermentation of the dough and further baking were carried out on Domino and Arianna devices. As a result of the research, it was revealed that only 7 test samples (Askeran, Azemetli 95, Gonen, Gyrmyzy Gul, Nurlu99, Tale38, Ugur) with a null allele, having subunit 1 (Glu-A1a allele), have a fragment of 344 bp in size, in the remaining 29 samples encoded by the Glu-A1 locus, having subunit 2* (Glu-A1b allele), a fragment of 362 bp in size is amplified. The presence of a null allele does not always have a negative effect on baking quality. The reason for this remains to be determined.

Genetic diversity of bread wheat (Triticum aestivum L.) in the allelic composition of HMW-GS (a review)

Background. The qualitative composition of wheat grain varies depending on the cultivar, soil and climate conditions, and agricultural practices. The allelic composition of glutenins in bread wheat cultivars is an important parameter for the analysis and management of their genetic structure. In this respect, there is an interest in studying the genetic diversity of alleles of high-molecular-weight glutenin subunits (HMW-GS) in bread wheat cultivars from Europe, Asia, Africa, and America.Materials and methods. The total diversity of alleles in Glu-1 glutenin loci was evaluated according to the calculation of the Nei index (H). Using this indicator and the cluster analysis, wheat cultivars of various ecogeographic origin were distributed into relatively homogeneous groups.Results. Wheat cultivars from Poland, Germany, France, Spain, Portugal, Turkey, Iran, Pakistan, India, China, and Algeria (Group I) had the average Nei index of 0.59, and those from the U.S., Mexico, Argentina, Russia, Kazakhstan, Ethiopia, Czech Republic, Hungary, Bulgaria, Afghanistan, and North Korea (Group II) had 0.42. These groups of wheat cultivars differed in the frequency of occurrence of glutenin subunits at each Glu-1 locus: N, 7+9, 2+12 in Group I, and 2*, 7+9, 5+10 in Group II.Conclusion. Wheat cultivars from Group II had on average a low level of variability of allelic genes in the respective loci, manifesting high grain quality of these cultivars and the highest probability of their genetic depletion compared to the cultivars from Group I, where most of the cultivars are described by a combination of low-quality glutenin subunits.

Genetic polymorphism of high-molecular-weight glutenin subunit loci in bread wheat varieties in the Pre-Ural steppe zone.

High-molecular-weight glutenins play an important role in providing high baking qualities of bread wheat grain. However, breeding bread wheat for this trait is very laborious and, therefore, the genotyping of variety samples according to the allelic composition of high-molecular-weight glutenin genes is of great interest. The aim of the study was to determine the composition of high-molecular-weight glutenin subunits based on the identification of the allelic composition of the Glu-1 genes, as well as to identify the frequency of the Glu-1 alleles in bread wheat cultivars that are in breeding work under the conditions of the Pre-Ural steppe zone (PSZ). We analyzed 26 winter and 22 spring bread wheat varieties from the PSZ and 27 winter and 20 spring varieties from the VIR collection. Genotyping at the Glu-A1 locus showed that the Ax1 subunits are most common in winter varieties, while the predominance of the Ax2* subunits was typical of spring varieties and lines. In the Glu-B1 locus, the predominance of alleles associated with the production of the Bx7 and By9 subunits was revealed for both winter and spring varieties. In the case of the Glu-D1 gene, for all the wheat groups studied, the composition of the Dx5+Dy10 subunits was the most common: in 92.3 % of winter and 68.2 % of spring PSZ accessions and in 80 % of winter and 55 % of spring VIR accessions. The analysis of genotypes showed the presence of 13 different allelic combinations of the Glu-A1, Glu-B1, Glu-D1 genes in the PSZ varieties, and 19 combinations in the VIR varieties. The b b/al/с d allelic combination (Ax2* Вх7+Ву8/8*/9 Dx5+Dy10) turned out to be the most common for the PSZ spring varieties and lines, while for the PSZ winter accessions it was a с d (Ax1 Вх7+By9 Dx5+Dy10); the b с a and b с d genotypes (Ax2* Вх7+Ву9 Dx2+Dy12 and Ax2* Вх7+Ву9 Dx5+Dy10, respectively) occur with equal frequency among the VIR spring accessions; in the group of VIR winter varieties, the combination of the a b/ al d alleles (Ax1 Вх7+Ву8/8* Dx5+Dy10) prevails. The most preferred combination of alleles for baking qualities was found in the spring variety 'Ekaterina' and winter varieties 'Tarasovskaya 97', 'Volzhskaya S3', as well as in lines k-58164, L43510, L43709, L-67, L-83, which are recommended for further breeding programs to improve and preserve baking qualities in the conditions of the Pre-Ural steppe zone.

Efficient proteome-wide identification of transcription factors targeting Glu-1: A case study for functional validation of TaB3-2A1 in wheat.

High-molecular-weight glutenin subunits (HMW-GS), a major component of seed storage proteins (SSP) in wheat, largely determine processing quality. HMW-GS encoded by GLU-1 loci are mainly controlled at the transcriptional level by interactions between cis-elements and transcription factors (TFs). We previously identified a conserved cis-regulatory module CCRM1-1 as the most essential cis-element for Glu-1 endosperm-specific high expression. However, the TFs targeting CCRM1-1 remained unknown. Here, we built the first DNA pull-down plus liquid chromatography-mass spectrometry platform in wheat and identified 31 TFs interacting with CCRM1-1. TaB3-2A1 as proof of concept was confirmed to bind to CCRM1-1 by yeast one hybrid and electrophoretic mobility shift assays. Transactivation experiments demonstrated that TaB3-2A1 repressed CCRM1-1-driven transcription activity. TaB3-2A1 overexpression significantly reduced HMW-GS and other SSP, but enhanced starch content. Transcriptome analyses confirmed that enhanced expression of TaB3-2A1 down-regulated SSP genes and up-regulated starch synthesis-related genes, such as TaAGPL3, TaAGPS2, TaGBSSI, TaSUS1 and TaSUS5, suggesting that it is an integrator modulating the balance of carbon and nitrogen metabolism. TaB3-2A1 also had significant effects on agronomic traits, including heading date, plant height and grain weight. We identified two major haplotypes of TaB3-2A1 and found that TaB3-2A1-Hap1 conferred lower seed protein content, but higher starch content, plant height and grain weight than TaB3-2A1-Hap2 and was subjected to positive selection in a panel of elite wheat cultivars. These findings provide a high-efficiency tool to detect TFs binding to targeted promoters, considerable gene resources for dissecting regulatory mechanisms underlying Glu-1 expression, and a useful gene for wheat improvement.

Analysis of genetic diversity and population structure using glutenin protein markers in various wheat varieties

AbstractThe study of polymorphism of glutenin makes it possible to identify and isolate desirable genotypes with higher grain quality. In the last few years, only a part of the genetic diversity among the modern and popular wheat germplasm and varieties based on the polymorphism of glutenin subunits are captured. To address this 107 wheat varieties released across different agricultural zones in India, were used to investigate HMW-GS and LMW-GS allele polymorphism, gene diversity and genetic variation in the Glu-1 and Glu-3 loci. Among the different HMW-GS, the highest genetic variation was observed at the Glu-D1 locus with both Glu-D1a and Glu-D1d possessing genetic variation of 0.490, 0.484 respectively. The highest genetic variation at the Glu-A3 locus was observed at the Glu-A3c and GluA3b possessing a genetic variation of 0.463, 0.411 respectively. This was followed by the Glu-B3j having a genetic variation of 0.386 at the Glu-B3 locus. Over 20 years a remarkable increase in the Glu-D1d allele is observed in the newly released varieties in India. Among all the zones, Glu-A1-null is the least frequent allele at the Glu-1 locus, however, it is present as the predominant allele in the NHZ of India. This study elucidates the relationships of these HMW and LMW allelic frequencies and genetic variation with their geographical distribution over the two different periods. This study provides reference data that can be used to assist the breeding, quality evaluation and development of good-quality wheat varieties.

Pinb-D1p is an elite allele for improving end-use quality in wheat (Triticum aestivum L.).

We identified ten QTLs controlling SDS-SV trait in a RIL population derived from ND3331 and Zang1817. Pinb-D1p is an elite allele from Tibetan semi‑wild wheat for good end-use quality. Gluten strength is an important factor for wheat processing and end-product quality and is commonly characterized using the sodium dodecyl sulfate-sedimentation volume (SDS-SV) test. The objective of this study was to identify quantitative trait loci (QTLs) associated with wheat SDS-SV traits using a recombinant inbred line (RIL) population derived from common wheat line NongDa3331 (ND3331) and Tibetan semi-wild wheat accession Zang1817. We detected 10 QTLs controlling SDS-SV on chromosomes 1A, 1B, 3A, 4A, 4B, 5A, 5D, 6B and 7A, with individual QTLs explaining 2.02% to 15.53% of the phenotypic variation. They included four major QTLs, Qsdss-1A, Qsdss-1B.1, Qsdss-1B.2, and Qsdss-5D, whose effects on SDS-SV were due to the Glu-A1 locus encoding the high-molecular-weight glutenin subunit 1Ax1, the 1B/1R translocation, 1Bx7 + 1By8 at the Glu-B1 locus, and the hardness-controlling loci Pina-D1 and Pinb-D1, respectively. We developed KASP markers for the Glu-A1, Glu-B1, and Pinb-D1 loci. Importantly, we showed for the first time that the hardness allele Pinb-D1p positively affects SDS-SV, making it a good candidate for wheat quality improvement. These results broaden our understanding of the genetic characterization of SDS-SV, and the QTLs identified are potential target regions for fine-mapping and marker-assisted selection in wheat breeding programs.

Diversity of alleles of locuses of spare proteins of wheat varieties IFRG NAS of Ukraine

Aim. Investigation of allele frequencies by locus of reserve proteins in groups of wheat varieties created during different selection periods at the leading breeding center of the Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine. Methods. The material for the study were 57 varieties of wheat of the Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine. Separation of gliadins was performed according to the ISTA method in the Poperel modification. High molecular weight glutenin subunits were analyzed by electrophoresis in the presence of sodium dodecyl sulfate (SDS) by the Lemmley method. Results. The allelic composition of loci of spare proteins Glu-A1, Glu-B1, Glu-D1, Gli-1A, Gli-B1, Gli-1D was determined. At the gliad-encoding loci Gli-A1, Gli-B1 6 alleles were detected, at the locus Gli-D1 - 5 alleles. By gluten-encoding loci, the most polymorphic was the Glu-B1 locus, which is represented by 5 alleles. Loci Glu-A1 and Glu-D1 are represented by 3 and 2 allelic variants. Conclusions. The frequency of the Glu-B1al allele, increased from 0% to 18%, this allele is one of the strongest in terms of positive impact on the quality of flour among the identified alleles of loci of high molecular weight glutenins of wheat. It was found that almost 50% of varieties created in the last decade in IFRG NAS of Ukraine have wheat-rye translocations 1AL.1RS, 1BL.1RS.

Effects of glutenins (Glu-1 and Glu-3) allelic variation on dough properties and bread-making quality of CIMMYT bread wheat breeding lines

Wheat dough characteristics and end-use quality are strongly influenced by the amount and specific composition of the glutenins, the major components of gluten. Such proteins are divided into high-molecular-weight glutenins, encoded by the Glu-A1 , Glu-B1 and Glu-D1 loci; and low-molecular-weight glutenins, encoded by the Glu-A3 , Glu-B3 and Glu-D3 loci. Allelic variation at each of these loci has been associated with changes in wheat functionality. However, most of the studies conducted so far included a relatively limited number of genotypes. Also for this reason, it is still unclear which locus contributes more to dough characteristics and how important are the interactions between the glutenin loci. To try to answer these questions, the quality data of 4623 grain samples derived from 2550 genotypes and generated across 10 years at the CIMMYT bread wheat breeding program, was used to estimate the effect of the glutenin loci and their interactions on gluten quality and bread-making potential. Gluten strength was the trait more strongly influenced by glutenin variations, with the Glu-B1 , Glu-D1 and Glu-B3 loci having the greatest effect. Among the glutenin alleles, Glu-A1a , Glu-A1b , Glu-B1al , Glu-B1i , Glu-B1f , Glu-D1d , Glu-A3b , Glu-A3d , Glu-A3f , Glu-B3c and Glu-B3d were associated in general with greater gluten strength, good extensibility and higher bread loaf volume. Differently, alleles Glu-A1c , Glu-B1a , Glu-B1d , Glu-D1a , Glu-A3e and Glu-B3j were associated with an overall poor quality. Glutenin interactions were significantly associated with most of the analyzed quality traits even if their influence was often lower compared to the effect of the single glutenin loci. This is probably the largest study ever done on the effects of the glutenins on wheat quality. The results obtained confirm the importance of such proteins on wheat quality variation and corroborate the usefulness of determining the glutenin profile to improve the selection efficiency for wheat quality in breeding programs. • Wheat quality and glutenin’s data of 4623 grain samples derived from 2550 genotypes was used. • Gluten strength was the trait more strongly influenced by glutenin variations. • Several alleles were associated to good or bad quality, respectively. • This is probably the largest study ever done about glutenins effects on quality.

Influence of high-molecular-weight glutenin subunit deletions at the Glu-A1 and Glu-D1 loci on protein body development, protein components and dough properties of wheat (Triticum aestivum L.)

High-molecular-weight glutenin subunits (HMW-GSs) play a critical role in determining the viscoelastic properties of wheat. As the organelle where proteins are stored, the development of protein bodies (PBs) reflects the status of protein synthesis and also affects grain quality to a great extent. In this study, with special materials of four near-isogenic lines in a Yangmai 18 background we created, the effects of Glu-A1 and Glu-D1 loci deletions on the development and morphological properties of the protein body, protein components and dough properties were investigated. The results showed that the deletion of the HMW-GS subunit delayed the development process of the PBs, and slowed the increases of volume and area of PBs from 10 days after anthesis (DAA) onwards. In contrast, the areas of PBs at 25 DAA, the middle or late stage of endosperm development, showed no distinguishable differences among the four lines. Compared to the wild type and single null type in Glu-A1, the ratios of HMW-GSs to low-molecular-weight glutenin subunits (LMW-GSs), glutenin macropolymer (GMP) content, mixograph parameters as well as extension parameters decreased in the single null type in Glu-D1 and double null type in Glu-A1 and Glu-D1, while the ratios of gliadins (Gli)/glutenins (Glu) in those types increased. The absence of Glu-D1 subunits decreased both dough strength and extensibility significantly compared to the Glu-A1 deletion type. These results provide a detailed description of the effect of HMW-GS deletion on PBs, protein traits and dough properties, and contribute to the utilization of Glu-D1 deletion germplasm in weak gluten wheat improvement for use in cookies, cakes and southern steamed bread in China and liquor processing.