Glu-D1 Locus Research Articles

Characterization of HMW glutenin subunits in European spring common wheat (Triticum aestivum L.)

High molecular weight glutenin subunits plays an important role in conditioning the end-use quality of wheat products. The aim of the study was to determine the composition of HMW glutenin subunits, occurrence frequency of theses subunits and the potential of the end—use quality in spring wheat. The analysis included 81 European cultivars of spring wheat with a potential use in the food industry. Eight gene-specific markers were used to screen for HMW-GS. The analyzed genotypes showed twenty-five different allelic combinations at the Glu-A1, Glu-B1 and Glu-D1 loci. The results showed that the most common at the Glu-A1 locus was Ax2* (58%), followed by Ax1 and Axnull (the same frequency of 21%). A high variation in allelic combinations was detected at the Glu-B1 locus. The Bx7* subunit was present in 65% cultivars, Bx7 in 25%, Bx7 or Bx7* in 7.5% and Bx6 in 2.5%. The frequency of By9 was 59%, By8—21% and Bynull—20%. A higher frequency of Dx5 + Dy10 (80%) was observed at Glu-D1 compared to Dx2 + Dy12 (16%) in the analyzed cultivars. A rare pattern of the Dx5 + Dy12 subunits was also detected (in 4% of cultivars tested). Ax2*, Bx7* + By9, Dx5 + Dy10 and Ax1, Bx7* + By9, Dx5 + Dy10, which determine good technological quality in wheat, were one of the most frequently detected allelic combinations at Glu-1. The conducted analysis showed that the tested cultivars were characterized by the potentially good and very good end-use quality of wheat products. These cultivars can be used effectively in the food industry.

MOLECULAR CHARACTERIZATION OF GENES FOR QUALITY TRAITS IN MACEDONIAN WHEAT GENOTYPES (Triticum aestivum L.)

The main goal of this study was to characterize glutenin subunits with high molecular weight (HMW-GS) in Macedonian wheat genotypes by using DNA markers and to analyse the polymorphism of the Glu-A1 and Glu-D1 loci, influencing wheat bread-making quality. Polymorphysm and allelic variations in the Glu-A1 loci were determined through characterization of Ax-null, Ax1 and Ax2* alleles, and in Glu-D1 loci through characterization of Dx2+Dy12 and Dx5+Dy10 alleles. Ax null, that has a negative influence on bread-making quality, was detected in 77.66% of the genotypes. The allelic pair Dx5+Dy10 was present in 68.09% of the genotypes. Only 8.51% of the analysed genotypes had the allele Ax1. According to the identified alleles in the Glu A1 and Glu D1 loci, the genotypes were grouped in two main clusters, 64 in the first and 30 genotypes in the second cluster. Both clusters consisted of three subclusters, comprising different number of genotypes. The most of the genotypes belonged to the subgroups 1a (presence of Dx5+Dy10) and 2a (presence of Dx2+Dy12). Genotypes in the 2a subgroup had Ах-null in Glu-A1 locus and Dx2+Dy12 in Glu-D1 locus, negatively influencing the wheat bread-making quality. These genotypes are not recommended to be used in a breeding program for improving wheat bread-making quality. Genotypes from the subgroups 1b and 1c possessed the alleles Аx2* and Ax1 in Glu-A1 locus and Dx5+Dy10 in Glu-D1 locus, indicating good bread-making quality. The superior breeding lines with improved quality, good agronomic characteristics and high yield have to be evaluated for their adaptability and stability. The lines with a complex of positive characteristics may be submitted for registration of new varieties. Further investigations of the material are needed for the other loci influencing the wheat bread-making quality.

Identification of Glu-A1 and Glu-D1 High Molecular Weight Glutenin Subunits of Common Wheat (Triticum aestivum L.) Using Genetic Markers

Abstract High molecular weight glutenin subunits (HMW-GS) of wheat are important factors in the determination of bread-making quality. They are responsible for elasticity and polymer formation of wheat dough. In the present study, 43 winter and 40 spring common wheat (Triticum aestivum L.) cultivars originated from Estonia, Belarus, Finland, Denmark, France, Germany, the Great Britain, Latvia, Lithuania, the Netherlands, Norway, Poland, Russia, Sweden, and New Zealand were characterised for Glu-A1 and Glu-D1 allelic composition using PCR method. Analyses were conducted with one DNA marker for identification of Glu-D1 allele encoding subunit Dx5, three DNA markers for Glu-A1 Ax1, Ax2* and AxNull subunits. It was determined that 32 (74.4%) winter and 35 (83.3%) spring cultivars had allele Glu-D1d, and 23 (53.5%) winter and 33 (78.6%) spring — Glu-A1a or Glu-A1b alleles, which have positive effect on dough properties. Polymorphism at Glu-A1 locus was detected in 15 cultivars, and 9 cultivars were polymorphic for locus Glu-D1. The obtained results were compared with published SDS-PAGE data. Complete or partial agreements were found for 78.1% of Glu-A1 and 70.6% of Glu-D1 alleles. Rapid and accurate identification of wheat Glu-1 alleles by molecular markers can be used for selection of wheat genotypes with good bread-making potential.

Studying Recombination between the 1RS Arms from the Rye Petkus and Insave Involved in the 1BL.1RS and 1AL.1RS Translocations using Storage Protein Loci as Genetic Markers

A population of F6 recombinant inbred lines from the cross between winter common wheat lines with the wheat-rye translocations 1BL.1RS (of the Kavkaz type) and 1АL.1RS (of the Amigo type), B-16 × 7086 AR, was produced. Using the storage protein loci Gli-R1, Gli-A1, and Gli-B1 as genetic markers, lines with recombinant 1RS (12%) were identified and the frequency of recombination between 1RS involved in different translocations was determined as 7%. 1RS from Amigo was demonstrated to carry a gene encoding the secalin “a”, which can be identified on SDS electrophoregrams under the y-subunit encoded by the Glu-D1 locus. The secalin “a” was also revealed in the cultivar MV Taltos, which was shown to carry the 1BL.1RS translocation with secalin alleles of the Amigo type. The gene encoding the secalin “a” was found to be allelic to the gene Sec-Nx from the rye Voronezhske SGI. The frequency of recombination between the loci Gli-R1 and Sec-N depends on the nature of the material analyzed and amounts about 10% (the genetic distance of 10 cM) in the cross MV Taltos × CWX (the lines with different 1BL.1RS translocations). Such a distance suggests that important disease and pest resistance genes, in particular stem rust resistance genes, are within the region flanked by these loci. Because of this the secalin loci are convenient for primary screening for recombinant 1RS arms with new combinations of disease and pest resistance genes.

Low molecular weight glutenin subunit gene composition at Glu-D3 loci of Aegilops tauschii and common wheat and a further view of wheat evolution.

A comprehensive comparison of LMW-GS genes between Ae. tauschii and its progeny common wheat. Low molecular weight glutenin subunits (LMW-GSs) are determinant of wheat flour processing quality. However, the LMW-GS gene composition in Aegilops tauschii, the wheat D genome progenitor, has not been comprehensively elucidated and the impact of allohexaploidization on the Glu-D3 locus remains elusive. In this work, using the LMW-GS gene molecular marker system and the full-length gene-cloning method, LMW-GS genes at the Glu-D3 loci of 218 Ae. tauschii and 173 common wheat (Triticum aestivum L.) were characterized. Each Ae. tauschii contained 11 LMW-GS genes, and the whole collection was divided into 25 haplotypes (AeH01-AeH25). The Glu-D3 locus in common wheat lacked the LMW-GS genes D3-417, D3-507 and D3-552, but shared eight genes of identical open reading frame (ORF) sequences when compared to that of Ae. tauschii. Therefore, the allohexaploidization induces deletions, but exerts no influence on LMW-GS gene coding sequences at the Glu-D3 locus. 92.17% Ae. tauschii had 7-9 LMW-GSs, more than the six subunits in common wheat. The haplotypes AeH16, AeH20 and AeH23 of Ae. tauschii ssp. strangulate distributed in southeastern Caspian Iran were the main putative D genome donor of common wheat. These results facilitate the utilization of the Ae. tauschii glutenin gene resources and the understanding of wheat evolution.

ALLELIC COMPOSITION OF HMW-GLUTENIN PROTEIN AND THEIR RELATIONSHIP WITH QUALITY OF WHEAT

High molecular weight glutenin subunits (HMW-GS) proteins deposited inendosperm of wheat seed which have significant impact on bread quality. TheHMW-GS encoded by genes located at the long arm of chromosomes 1A, 1B, 1D.The aim of this work was study allele polymorphysms at Glu-A1, Glu-B1 and Glu-D1 locus and loaf volume, grain protein content, sedimentation volume of eightwheat genotypes (G-3130, G-35183, G-3501, G3512, G-3574, G-3027, G-3075, G-3097) harvested in two years with various weather condition. For each genotypes,flour used for extraction of glutenin which separated by method of electrophoresison SDS gel (11.8%). Electrophoregrams used for determining Glu-1 alleles.Technological quality parameters analyzed by standard laboratory methods. Thethree alleles alleles (a, b, c) at the Glu-A1, three alleles (b, c, d) at the Glu-B1 and 2alleles (a, d) at the Glu-D1 were identified. The highest protein sedimentationvolume had wheat genotype G-3075 in the both years (54.0ml; 58.0ml) while thelowest sedimentation volume had G-3512 (34.0ml; 36.0ml). Grain protein content(GPC) was the highest in G-3075 in both years (14.20%; 15.40%) while the lowestGPC had G-3097 (11.60%) in first and G-3512 (12.60%) in the second year. Loafvolume was the highest in G-3075 in both year (520ml; 540ml) while the lowestwas in G-3512 (400ml) in both years of experiment. The estimated quality traitsvaried depending on genotype and year. The better quality, in average, had thewheat genotypes which carried Glu-D1d allele.

Analysis of Glu-1 loci in samples of rare wheat species and their hybrides

Aim. Determination of the allelic composition of Glu-1 loci in samples of rare wheat species and their hybrids with spring bread wheat. Methods. PCR analysis. Results. In existing collection samples of the rare wheat species the alleles of the a/c loci Glu-A1 were found, while allele b was found only in T.dicoccum, var. volgense (Emmer Kokchetavskaya). An additional amplicon with a length of 450 bp was found in the Glu-A1 locus in the sample (T. dicoccum × Dasypyrum villosum), and in (Ae. ventricosa × T. dicoccum) another one a length of 700 bp in genome B, was found require further research. Among hexaploid wheat, it was revealed genotypes differing in the presence of alleles a and d of the locus Glu-D1. The hybridity of the received forms has been confirmed, as evidenced by the identification of both parent components in the hybrids or alleles of the Glu-D1 locus of bread wheat in hybrids with emmer. Conclusions. Analysis of the allele composition of Glu1 locuses in samples of rare wheat species and their hybrids with bread wheat allowed to select genotypes and hybrid combinations that may be promising for further breeding work.
 Keywords: Triticum spelta L., T. dicoccum, hybrids, PCR analysis, Glu-1 locus.

Allelic variation of high molecular weight glutenin subunits of bread wheat in Hebei province of China

In common wheat (Triticum aestivum L.), allelic variations of Glu-1 loci have important influences on grain end-use quality. The allelic variations in high molecular weight glutenin subunits (HMW-GSs) were identified in 151 hexaploid wheat varieties representing a historical trend in the cultivars introduced or released inHebei province ofChina fromthe years 1970s to 2010s.Thirteen distinct alleles were detected for Glu-1. At Glu-A1, Glu-B1 and Glu-D1, we found that the most frequent alleles were the 1 (43.0%), 7+8 (64.9%), 2+12 (74.8%) alleles, respectively, in wheat varieties. Twenty two different HMW-GS compositions were observed in wheat. Twenty-five (16.6%) genotypes possessed the combination of subunits 1, 7+8, 2+12, 25 (16.6%) genotypes had subunit composition of 2*, 7+8, 2+12; 20 (13.2%) genotypes had subunit composition of null, 7+8, 2+12. The frequency of other subunit composition was less than 10%. The Glu-1 quality score greater than or equal to 9 accounted for 20.6% of the wheat varieties. The percentage of superior subunits (1 or 2* subunit at Glu-A1 locus; 7+8, 14+15 or 17+18 at Glu-B1 locus; 5+10 or 5+12 at Glu-D1 locus) was an upward trend over the last 40 years. The more different superior alleles correlated with good bread-making quality should be introduced for their usage in wheat improvement efforts.

Biochemical and Molecular Characterization of Bangladeshi Wheat Varieties for Bread-Making Quality

Twenty-six wheat genotypes including 18 Bangladeshi varieties and 8 varieties/lines collected from different countries were evaluated for their breadmaking quality. Total grain protein content was measured using Kjeldahl method. Presence of the high molecular weight glutenin subunits (HMW-GS) and their corresponding genes were characterized through SDS-PAGE and PCR based methods. Total protein content of 53.85% of the genotypes ranged between 12 and 14% which is considered as a suitable range of protein for making bread. At the Glu-A1 locus, Ax2* alleles were found with a frequency of 84.62%. At the Glu-B1 locus, 4 different alleles; Bx7, Bx7+By8, Bx7+By9 and Bx17+By18 were detected. At the Glu-D1 locus, PCR test result showed that 61.11% Bangladeshi wheat varieties contain Dx5+Dy10, regarded as the best allele for making bread. Four genotypes, Kalyansona, Sonora-64, Pavon-76 and BARI Gom 28, were found to have the highest quality score of 10. Among those, Kalyansona and BARI Gom 28 had the best HMW-GS combination of Ax2*, Bx17+By18, Dx5+Dy10 and Ax2*, Bx7+By8, Dx5+Dy10, respectively. This study will be important for specifying wheat genotypes for the food industry and further breeding for bread-making quality.Plant Tissue Cult. & Biotech. 28(1): 57-68, 2018 (June)

Exploring diverse wheat germplasm for novel alleles in HMW-GS for bread quality improvement.

Wheat is one of the most important cereals used worldwide in the form of a range of products. Crop landraces have been an immense source of diversity for the breeders. In the present study, 517 Indian wheat landraces have been observed for the difference in bread making quality by assessing allelic behaviour of high molecular weight-glutenin subunits (HMW-GS). A total of 33 Glu-1 alleles (3 at Glu-A1, 15 at Glu-B1 and 15 at Glu-D1) were detected in wheat landraces. Allelic frequency of HMW-GS allelic band pattern null, 17 + 18, 2 + 12 (24.75%) was found to be the highest. Allelic frequency of HMW-GS allele null (68.27%) at Glu-A1, 17 + 18 (49.14%) at Glu-B1, and 2 + 12 (72.81%) at Glu-D1 was found to be the highest Five Novel alleles were identified at Glu-D1 locus, 12*, 12.1, 12.1*, 12.2 and 12.3. As Glu-D1 has highest quality contribution as compared to Glu-A1 and Glu-B1, reporting novel alleles at Glu-D1 represents that genetic variability available for selection is increased and it will provide tools for breeders to further improve dough properties and bread making quality.

Effect of high-molecular-weight glutenin subunit deletion on soft wheat quality properties and sugar-snap cookie quality estimated through near-isogenic lines

High-molecular-weight glutenin subunits (HMW-GSs) play a critical role in determining the viscoelastic properties of wheat dough. The HMW-GSs are encoded by Glu-A1, Glu-B1, and Glu-D1 loci on the long arms of chromosomes 1A, 1B, and 1D, respectively. In the present study, four near-isogenic lines with different HMW-GS deletions and compositions at the Glu-A1 and Glu-D1 loci in Yangmai 18 background were used for quality analysis. Deletion in Glu-D1 showed much weaker gluten quality and dough strength than null Glu-A1 genotype and wild genotype (WT), based on the measurements of sodium dodecyl sulfate (SDS)-sedimentation, lactic acid solvent retention capacity (SRC), gluten index, development time, stability time, and alveograph P and L values. The deletion of Glu-D1 did not significantly affect grain hardness, grain protein content, water SRC, sodium carbonate SRC, and sucrose SRC. Double null genotype in Glu-A1 and Glu-D1 and single null genotype in Glu-D1 showed significantly higher cookie diameter, crispness, and lower cookie height compared with single null genotype in Glu-A1 and WT. These indicate that the null Glu-D1 genotype is useful for improvement of biscuit quality, and use of this germplasm would be a viable strategy to develop new wheat varieties for biscuit processing.

Development of haplotype-specific molecular markers for the low-molecular-weight glutenin subunits

Low-molecular-weight glutenin subunits (LMW-GSs) are one of the major components of gluten, and their allelic variation has been widely associated with different wheat end-use quality parameters. These proteins are encoded by multigene families located at the orthologous Glu-3 loci (Glu-A3, Glu-B3, and Glu-D3); the genes at each locus are divided by large intergenic and highly recombinogenic regions. Among the methods used for the LMW-GS allele identification, polymerase chain reaction (PCR)-based molecular markers have the advantages of being simple, accurate, and independent from the plant stage of development. However, the available LMW-GS molecular markers are either incapable of capturing the complexity of the LMW-GS gene family or difficult to interpret. In the present study, we report the development of a set of PCR-based molecular markers specific for the LMW-GS haplotypes present at each Glu-3 locus. Based on the LMW-GS gene sequences available in GenBank, single nucleotide polymorphisms (SNPs) specific for each Glu-3 haplotype were identified and the relevant PCR primers were designed. In total, we developed three molecular markers for the Glu-A3 and Glu-B3 loci, respectively, and five molecular markers for the Glu-D3 locus. The markers were tested on 44 bread wheat varieties previously characterized for their LMW-GS genic profile and found to be equally or more efficient than previously developed LMW-GS PCR-based markers. This set of markers allows an easier and less ambiguous identification of specific LMW-GS haplotypes associated with gluten strength and can facilitate marker-assisted breeding for wheat quality.

Geographical comparison of genetic diversity in Asian landrace wheat (Triticum aestivum L.) germplasm based on high-molecular-weight glutenin subunits

Glutenin largely determines wheat bread baking quality. As high-molecular-weight glutenin subunit (HMW-GS), related to Glu-1 loci, determines wheat flour elasticity, it correlates strongly with bread-making quality. This study was aimed at clarifying genetic variations in bread-making characteristics between East and West Asian wheat landrace germplasms, by investigating HMW-GS allelic composition of 1068 wheat accessions. Herein, the accession number having reported HMW-GS pattern in previous studies was 855. However, the accession number with newly detected HMW-GS patterns was 114. These new HMW-GS patterns were classified into 4 types based on similarity. Eight Korean accessions with these four types were identified. Concerning landrace germplasm nature, 99 accessions showed heterogeneous patterns caused by seed mixture. The Glu-1 loci allelic variation analysis, revealed that the percentages of Glu-A1c (73.6%), Glu-B1b (60.2%), and Glu-D1a (68.5%) were highest at Glu-A1, Glu-B1, and Glu-D1 loci, respectively. The incidence of preferable alleles for bread baking was high in Chinese accessions. In bread-making quality evaluation using Glu-1 score, 24 among 35 accessions with full score were from China. The polymorphic information content index of each origin based on HMW glutenin subunit combination showed that West Asian and neighboring-regional landraces, excluding Afghanistan ones, were more diverse than East Asian landraces excluding Chinese ones. Cluster analysis based on Glu-1 allelic combination showed that many Korean, Japanese, and Afghan accessions were in the same group. However, many Chinese and other West Asian accessions were in the other group despite geographical distance.

Molecular profiling of a y-type high molecular weight glutenin subunit at Glu-D1 locus from a North Korean landrace wheat (Triticum aestivum L.)

The objective of this study is to demonstrate characteristics of a y-type high molecular weight glutenin subunit (D1y HMW-GS) at Glu-D1 found in IT212991, a North Korean landrace wheat compared to Dy12 and Dy12.K as a novel HMW-GS in JB20, a Korean wheat line onto molecular analyses as PCR, cloning, DNA sequencing, and RP-HPLC and proteomic analyses as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE), two-dimensional electrophoresis (2-DE), Fourier-transform mass spectrometry (LTQ-FT-MS). The D1y of IT212991 was identified to have faster electrophoretic mobility than that of Dy12 by SDS–PAGE. HMW-GS components of IT212991 were identified to be different from Chinese Spring (CS) and JB20, a Korean wheat line by RP-HPLC. The result of mass spectrometric analysis, the D1y of IT212991 (68510.8 Da) was similar to that of Dy12.K of JB20 (68514.4 Da), and lower than Dy12 of CS (69151.2 Da). The result of LTQ-FT-MS based on 2-DE, the D1y of IT212991 was identified to be similar with Dy12 corresponding to the protein function as ‘Glutenin, high molecular weight subunit 12’. The D1y encoding the D1y of IT212991 was identified to consist of 652 amino acid sequences corresponding to 1962 bp according to DNA sequencing. The gene was identified to have a insertion and deletion (InDel) corresponding to 18 bp sequences ‘AACAGGACAAGGGCAACA’ compared to ordinary Dy12 gene. It was demonstrated that the D1y of IT212991 is the same as Dy12.K.

Proteomic analysis of low-molecular-weight glutenin subunits and relationship with their genes in a common wheat variety.

Although many studies on low-molecular-weight glutenin subunit (LMW-GS) function have been reported, a comprehensive comparison between specific genes and their protein product is still lacking. This study aimed to link the 43 genes isolated from the Korean wheat variety "Jokyoung" in the authors' previous study to their protein products. Proteins were separated using two-dimensional gel electrophoresis (2-DGE) and identified by tandem mass spectrometry (MS/MS) at the gene haplotype level. Using MS/MS analysis of 17 protein spots, two spots wereidentifiedin the Glu-A3 locus and the corresponding haplotype wasGluA3-13(Glu-A3c). Six spots were identified in the Glu-B3 locus and the corresponding haplotypes were GluB3-33 and GluB3-43 (Glu-B3h). Eight spots were identified in the Glu-D3 locus and the corresponding haplotypes were GluD3-11, GluD3-21, GluD3-31, GluD3-5, and GluD3-6 (Glu-D3a), and one spot was contaminated with gamma gliadin. Phylogenetic analysis and alignment of nucleotide and amino acid sequences assigned 35 of the 43 genes to seven haplotypes: GluA3-13, GluB3-43, GluD3-11, GluD3-21, GluD3-31, GluD3-42, and GluD3-5. Taken together, except for GluB3-33 and GluD3-6, which were not isolated, linking of each gene to the corresponding protein products at the gene haplotype level was accomplished using proteomic tools and phylogenetic analysis.

EVALUTION OF THE EFFECT OF THE NEW FRACTION PAIR 1Dx1.5+1Dy10 INHERITED FROM Glu-Dt LOCUS OF Ae. Tauschii (DtDt, 2n=14) ON SOME QUALITATIVE INDICES IN THE PROGENIES OF SYNTHETIC WHEAT VARIETIES (BBАuАuDtDt, 2n=42)

The effect of the new fraction pair 1.5+10, coded by Glu-D1 locus, on the qualitative indices protein, lysine and sedimentation value in synthetic hexaploid wheat varieties was investigated in comparison to common winter wheat standards. For this purpose, in two successive cropping seasons (2013 and 2014), grains from plants of the progenies of the synthetic haploid wheat genotypes 106, 107 and 32 were analyzed; preliminary SDS-PAGE analysis determined that they were carriers of the new allele ah inherited from the Glu-Dt1 locus of Ae. tauschii. Data were analyzed with the help of descriptive statistics, t-criterion, correlation and regression analyses, which were at the basis of the conclusions made. The obtained results allow the assumption that in the synthetic hexaploid wheat genotypes the new allele ah, coding for the expression of the new fraction pair 1.5+10 in D-genome, has positive effect on the qualitative indices protein, lysine and sedimentation in contrast to the standard common wheat cultivars, which do no carry this subunit.

Allelic variation of high-molecular-weight glutenin genes in bread wheat

The composition and quantity of high-molecular-weight glutenin subunits plays an important role in determining the bread-making quality of wheat. Molecular-genetic analysis of allelic composition of high-molecular-weight glutenin genes in 102 bread wheat cultivars and lines from different geographical regions was conducted. Three alleles at the Glu-A1 locus, nine alleles at the Glu-B1 locus, and two alleles at the Glu-D1 locus were identified. Among the investigated cultivars and lines, 21 were characterized by intracultivar polymorphism. High allelic variation of high-molecular-weight glutenin subunit genes was shown for the collection: 21 and 9 combinations were defined in monomorphic and polymorphic cultivars and lines, respectively. However, the major part of the collection (66.7%) contained four allelic combinations: Glu-A1b Glu-B1c Glu-D1d, Glu-A1b Glu-B1c Glu-D1-2a, Glu-A1a Glu-B1c Glu-D1d, and Glu-A1b Glu-B1c Glu-D1d/Glu-D1-2a. Fourteen cultivars of bread wheat were selected, and they were characterized by a favorable allelic composition of Glu-1 loci.

Doubled haploid wheat lines with high molecular weight glutenin alleles derived from microspore cultures

ABSTRACTA doubled haploid (DH) production system for wheat using a microspore culture method produced seeds and subsequently regenerated haploid wheat plants derived from the F1 plants of two wheat populations (Irena × Ksu102 and Klasic × Ksu105). 68 DH were obtained from both populations. Field trials of these DH lines were conducted over two seasons. Genotypic differences were highly significant for all agronomic traits recorded. Sets of five gene- or allele-specific PCR markers were used for identification of genes encoding high molecular weight (HMW) glutenin subunits Ax1 and Ax2* at the Glu-A1 locus, Bx7, Bx7*, By8 and By17 at the Glu-B1 locus and Dx5, Dy10 and Dy12 at the Glu-D1 locus in wheat inbred lines. The method developed for providing DH lines and subsequent molecular analysis and quality could be useful for improving bread-making quality and developing new cultivars.Abbreviations: DH: doubled haploid; HMW: high molecular weight; HMW-GS: high molecular weight glutenins subunits; MAB: marker-assisted breeding

Genome-Wide Associations for Water-Soluble Carbohydrate Concentration and Relative Maturity in Wheat Using SNP and DArT Marker Arrays.

Improving water-use efficiency by incorporating drought avoidance traits into new wheat varieties is an important objective for wheat breeding in water-limited environments. This study uses genome wide association studies (GWAS) to identify candidate loci for water-soluble carbohydrate accumulation—an important drought-avoidance characteristic in wheat. Phenotypes from a multi-environment trial with experiments differing in water availability and separate single nucleotide polymorphism (SNP) and diversity arrays technology (DArT) marker sets were used to perform the analyses. Significant associations for water-soluble carbohydrate accumulation were identified on chromosomes 1A, 1B, 1D, 2D, and 4A. Notably, these loci did not collocate with the major loci identified for relative maturity. Loci on chromosome 1D collocated with markers previously associated with the high molecular weight glutenin Glu-D1 locus. Genetic × environmental interactions impacted the results strongly, with significant associations for carbohydrate accumulation identified only in the water-deficit experiments. The markers associated with carbohydrate accumulation may be useful for marker-assisted selection of drought tolerance in wheat.

Characterization of a novel y-type high molecular weight glutenin subunit at Glu-D1 locus

Glu-D1y12.K as a novel y-type subunit was found in HMW-GSs encoded at the Glu-D1 locus in the JB20, which a Korean wheat line from F9 lines crossed by Keumkang with Glu-D1d and Chinese Spring (CS) with Glu-D1a alleles. This novel subunit shows faster electrophoretic mobility and lower molecular weight than Dy12 subunit on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The result of linear ion-trap and Fourier-transform mass spectrometry (LTQ-FT-MS) based on two-dimensional electrophoresis (2-DE) showed that the Dy12.K subunit has high similarity against protein ID: P08488 (GLT3_WHEAT) as ‘Glutenin, high molecular weight subunit 12’ form UniProtKB. The gene of the Glu-1Dy12.K subunit is composed of 1962 nucleotide base pairs containing open reading frame (ORF) as 652 amino acids corresponding to about 70.1 kDa. It has four indels (36 bp insertions: two repeated 18 and 24 bp deletion: two deletions with 6 + 18 bp) and 21 SNPs compared to Glu-1Dy10 (GI: 164457872 in NCBI), and one deletion (18 bp) and three SNPs compared to Glu-1Dy12 (GI: 1036031968) by DNA markers. Consequentially, in comparison with Dy10, 13 SNPs were non-synonymous SNPs and eight SNPs were synonymous SNPs of 21 SNPs. In comparison with Dy12, only one SNP was non-synonymous SNP of three SNPs. Furthermore, the deduced peptide sequences as ‘TGQGQQ’ corresponding to ‘AACAGGACAAGGGCAACA’ are deleted only in the Dy12.K subunit.