Analysis of diversity of russian and Ukrainian bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) cultivars for high-molecular-weight glutenin subunits

The allelic diversity of high-moleculat-weght glutenin subunits (HMWGS) in Russian and Ukrainian bread wheat cultivars was analyzed. The diversity of spring wheat cultivars for alleles of the Glu-1 loci is characterized by medium values of the polymorphism polymorphism information content (PIC), and in winter wheats it varies from high at the Glu-A1 locus to low at the Glu-D1 locus. The spring and winter cultivars differ significantly in the frequencies of alleles of the glutenin loci. The combination of the Glu-A1b, Glu-B1c, and Glu-D1a alleles prevails among the spring cultivars, and the combination of the Glu-A1a, Glu-B1c, and Glu-D1d alleles prevails among the winter cultivars. The distribution of the Glu-1 alleles significantly depends on the moisture and heat supply in the region of origin of the cultivars. Drought resistance is associated with the Glu-D1a allele in the spring wheat and with the Glu-B1b allele in the winter wheat. The sources of the Glu-1 alleles were identified in the spring and wheat cultivars. The analysis of independence of the distribution of the spring and winter cultivars by the market classes and by the alleles of the HMWGS loci showed a highly significant association of the alleles of three Glu-1 loci with the market classes in foreign cultivars and independence or a weak association in the Russian and Ukrainian cultivars. This seems to be due to the absence of a statistically substantiated system of classification of the domestic cultivars on the basis of their quality.     

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.     

Multiplex PCR identification of wheat HMW glutenin subunit genes by allele-specific markers

Wheat bread-making quality is closely correlated with composition and quantity of gluten proteins, in particular with high-molecular weight (HMW) glutenin subunits encoded by the Glu-1 genes. A multiplex polymerase chain reaction (PCR) method was developed to identify the allele composition of HMW glutenin complex Glu-1 loci (Glu-A1, Glu-B1 and Glu-D1) in common wheat genotypes. The study of multiplex PCR to obtain a well-balanced set of amplicons involved examination of various combinations of selected primer sets and/or thermal cycling conditions. One to three simultaneously amplified DNA fragments of HMW glutenin Glu-1 genes were separated by agarose slab-gel electrophoresis and differences between Ax1, Ax2* and Axnull genes of Glu-A1 loci, Bx6, Bx7 and Bx17 of Glu-B1, and Dx2, Dx5 and Dy10 genes of Glu-D1 loci were revealed. A complete agreement was found in identification of HMW glutenin subunits by both multiplex PCR analysis and SDS-PAGE for seventy-six Polish cultivars/strains of both spring and winter common wheat. Rapid identification of molecular markers of Glu-1 alleles by multiplex PCR can be an efficient alternative to the standard separation procedure for early selection of useful wheat genotypes with good bread-making quality.     

Allelic variations in <Emphasis Type="Italic">Glu-1</Emphasis> and <Emphasis Type="Italic">Glu-3</Emphasis> loci of historical and modern Iranian bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) cultivars

Proline and glutamine-rich wheat seed endosperm proteins are collectively referred to as prolamins. They are comprised of HMW-GSs, LMW-GSs and gliadins. HMW-GSs are major determinants of gluten elasticity and LMW-GSs considerably affect dough extensibility and maximum dough resistance. The inheritance of glutenin subunits follows Mendelian genetics with multiple alleles in each locus. Identification of the banding patterns of glutenin subunits could be used as an estimate for screening high quality wheat germplasm. Here, by means of a two-step 1D-SDS-PAGE procedure, we identified the allelic variations in high and low-molecular-weight glutenin subunits in 65 hexaploid wheat (Triticum aestivum L.) cultivars representing a historical trend in the cultivars introduced or released in Iran from the years 1940 to 1990. Distinct alleles 17 and 19 were detected for Glu-1 and Glu-3 loci, respectively. The allelic frequencies at the Glu-1 loci demonstrated unimodal distributions. At Glu-A1, Glu-B1 and Glu-D1, we found that the most frequent alleles were the null, 7 + 8, 2 + 12 alleles, respectively, in Iranian wheat cultivars. In contrast, Glu-3 loci showed bimodal or trimodal distributions. At Glu-A3, themost frequent alleles were c and e. At Glu-B3 the most frequent alleles were a, b and c. At Glu-D3 locus, the alleles b and a, were the most and the second most frequent alleles in Iranian wheat cultivars. This led to a significantly higher Nei coefficient of genetic variations in Glu-3 loci (0.756) as compared to Glu-1 loci (0.547). At Glu-3 loci, we observed relatively high quality alleles in Glu-A3 and Glu-D3 loci and low quality alleles at Glu-B3 locus.     

Identification and characterization of high-molecular-weight glutenin genes in Polish triticale cultivars by PCR-based DNA markers

Molecular markers were used to identify the allele/gene composition of complex loci Glu-A1 and Glu-B1 of high-molecular-weight (HMW) glutenin subunits in triticale cultivars. Forty-six Polish cultivars of both winter and spring triticale were analysed with 7 PCR-based markers. Amplified DNA fragments of HMW glutenin Glu-1 genes were separated by agarose slab-gel electrophoresis. Differences between all 3 alleles at the locus Glu-A1 [Glu-A1a (encoding Ax1), 1b (Ax2*), and 1c (AxNull)], 4 alleles at Glu-B1-1 [Glu-B1-1a (Bx7), 1b (Bx7*), 1d (Bx6), 1ac (Bx6.8)], and 5 alleles at Glu-B1-2 [Glu-B1-2a (By8), 2b (By9), 2o (By8*), 2s (By18*), and 2z (By20*)] were revealed. In total, 16 allele combinations were observed. Molecular markers are particularly helpful in distinguishing the wheat Glu-A1a and Glu-A1b alleles from the rye Glu-R1a and Glu-R1b alleles in triticale genotypes, respectively, as well as subunits Bx7 from Bx7* and By8 from By8*, which could not be distinguished by SDS-PAGE. Novel glutenin subunits By18* and By20* (unique to triticale) were identified. HMW glutenin subunit combinations of Polish triticale cultivars, earlier identified by SDS-PAGE analyses, were verified by PCR-based DNA markers. Rapid identification of wheat Glu-1 alleles by molecular markers can be an efficient alternative to the standard separation procedure for early selection of useful triticale genotypes with good bread-making quality.     

西南冬麦区地方品种HMW-GS组成遗传多样性研究

采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)对西南冬麦区(云南、贵州、四川)3个省份共计560份小麦地方品种的高分子量谷蛋白亚基(HMW-GS)组成进行了研究。结果表明:Glu-1位点共有22种等位基因,其中Glu-A1位点4种、Glu-B1位点11种、Glu-D1位点7种;亚基null、7 8和2 12在各自位点的频率最高,分别为89.64%、68.21%和96.43%。亚基组成类型共有46种,以null/7 8/2 12和null/7 9/2 12为主,频率分别为50.89%和11.79%。在这些材料中筛选出一些含有1、2*、17 18、14 15、5 10等优质亚基的材料,其中有52份材料含有优质亚基组合。     

High Molecular Weight Glutenin Subunit Composition of Indian Wheats and Their Relationships with Dough Strength

One hundred and seventy two wheat varieties including twenty-five durum wheat cultivars were evaluated for high molecular weight glutenin subunit (HMW-GS) composition using SDS-PAGE. The relationship between HMW-GS and sedimentation tests for dough strength was studied. Three alleles were present at the Glu-A1 locus, eight at Glu-B1 and two at Glu-D1 in bread wheat. The data indicated the prevalence of the Glu-A1b allele (63.5%) at the Glu-A1 and Glu-D1a (71.4%) at Glu-D1 loci. Three alleles, namely Glu-B1b (30.61%), Glu-B1c (25.85%) and Glu-B1i (34.00%) represented about 90% of the alleles at Glu-B1 locus. The combination of Glu-A1b, Glu-B1i and Glu-D1d alleles exhibited highest dough strength as measured by sedimentation value in comparison to other combinations (p<0.001). However, this combination was present only in 7% of the samples evaluated. In durum wheat, the null allele (Glu-A1c) was observed more frequently (76%) than the Glu-A1b allele (24%). Glu-B1f and Glu-B1e alleles represented equally (32% each). Protein subunits 13+16 and 6+8 were found correlated positively (p<0.05) with improved dough strength as compared to subunit 20 in durum wheat. This information can be a valuable reference for designing breeding programme for the improvement of bread and pasta making quality of bread and durum wheats, respectively in India.     

小麦新品种(系)Glu-1位点等位基因变异研究

应用SDS-PAGE技术分析了40份小麦新品种(系)的高分子量麦谷蛋白亚基等位基因变异。在Glu-1位点共检测到10种变异类型,其中Glu-Al位点有3种类型：Null、1、26 ,Glu-B1位点有5种类型：7 8、7 9、14 15、7、17 18,Glu-D1位点有2种类型：2 12、5 10;Null(54．3％)、7 8(51．4％)和2 12(62．9％)分别是Glu-Al、Glu-B1和Glu-D1位点上的主要亚基变异类型。另外,在2份材料的Glu-B1和Glu-D1位点各检测到1个新的亚基,分别命名为1By8．1和1Dx5^ 。Glu-1位点的Nei‘s遗传变异指数平均为0,5648,Glu-B1的遗传多样性最高,Glu-D1最低。供试小麦材料Glu-1位点的HMW-GS组合共有17种类型,以(Null,7 8,2 12)组合为主要类型,占31．4％;有9种亚基组合类型分别只在1份材料中出现,占26.1％。结果表明,这些小麦新品种(系)存在着丰富的亚基组合类型。     

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 in Hebei province of China from the 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.     

Gene-assisted selection for high molecular weight glutenin subunits in wheat doubled haploid breeding programs

Molecular markers based on DNA sequence variations of the coding and/or promoter regions of the wheat (Triticum aestivum L.) HMW glutenin genes located at the Glu-1 loci were developed. Markers characteristic of alleles Glu-A1-1a (encoding Ax1 subunit) and Glu-A1-1c (encoding Ax2* subunit) at the Glu-A1 locus, alleles Glu-B1ak (encoding Bx7* subunit) and Glu-B1al for overexpressed Bx7 subunit at the Glu-B1 locus and alleles Glu-D1-1a (encoding Dx2 subunit) and Glu-D1-1d (encoding Dx5 subunit) at the Glu-D1 locus were tested using genomic DNA of haploid leaf tissue. A method for simultaneously extracting DNA from 96 haploid leaf tissue pieces is described. Two of the developed markers were dominant and two were co-dominant. A F₁-derived population segregating for all HMW glutenin genes was used to test the validity of the markers and their usefulness in doubled haploid breeding programs. SDS-PAGE analysis of seed storage protein was performed on seeds from the doubled haploid lines. A total of 299 lines were tested with the DNA markers on the haploid tissue and validated by protein analysis of the corresponding DH seeds. PCR markers and SDS-PAGE analysis showed between 2 and 8.5% discrepancies depending on the marker. Applications of DNA markers for gene-assisted-selection of haploid tissue and use in breeding programs are discussed. Advantages and disadvantages of dominant and co-dominant markers are outlined.     

Genetic Diversity of Gli-1, Gli-2 and Glu-1 Alleles in Sichuan Wheat Landraces

Genetic diversity at Gli-1, Gli-2 and Glu-1 loci was investigated in 89 Sichuan wheat ( Triticum aestivum L.) landraces by using acid polyacrylamide gel electrophoresis (APAGE) and SDS-PAGE. In these landraces, a total of 32 gliadin and 3 high-molecular-weight (HMW) glutenin patterns were observed. In total, 14, 15 and 5 alleles were identified at Gli-1, Gli-2 and Glu-1, respectively. At each locus, the alleles in higher frequency were Gli-A1a (89%), Gli-B1 h (46%), Gli-D1a (65%), Gli-A2a (64%), Gli-B2j (45%), Gli-D2 a (48%), Glu-A1c (99%), Glu-B1b (99%) and Glu-D1a (100%). The Nei's genetic variation index (H) of Sichuan wheat landraces was 0.3706, varying from 0 to 0.7087. The highest genetic diversity was found at Gli-B2 locus, while the lowest was found at Glu-D1 . The genetic diversity at Gli loci was higher than that of Glu-1 loci among these landraces, but it was much lower than that of modern wheat cultivars. These results indicated a narrow genetic base of Sichuan wheat landraces. In this study, “Chengdu-guangtou” had the identical gliadin and HMW-glutenin patterns with “Chinese Spring”, further supporting the proposal that “Chinese Spring” is a strain of “Chengdu-guangtou”.     

西藏半野生小麦高分子量麦谷蛋白亚基组成分析

应用SDS-PAGE分析了50份西藏半野生小麦(Triticum aestivum ssp.tibetanum Shao)的高分子量麦谷蛋白亚基等位基因组成。结果表明,43份材料的HMW-GS组成是同质的,7份材料为异质。供试材料共有7种HMW GS组合,以Null、7 8、2 12为主要类型,占所分析材料的68．4％。在Glu-1位点共检测到10种等位基因,Glu- A1位点2种,Glu～B1位点4种,Glu～D1位点4种。Null(96％)、7 8(80．4％)和2 12(94．9％)分别是Glu-A1、 Glu-B1和Glu～D1位点上主要的等位基因。在Glu-B1位点还新发现2个亚基,暂时分别命名为8*和7**。说明西藏半野生小麦中存在着较广泛的HMW-GS等位基因变异,是小麦品质育种潜在的可利用的遗传资源。     

Variation at storage protein loci in winter common wheat cultivars of the central forest-steppe of Ukraine

Genotypes at the gliadin loci Gli-A1, Gli-B1, Gli-D1 and the high-molecular-weight glutenin subunit loci Glu-A1, Glu-B1, Glu-D1 were identified in 77 winter common wheat cultivars developed in the Central Forest Steppe of Ukraine in different periods of time. The highest level of variation was observed at the Gli-A1 locus. Predominant alleles (one or two per locus) were revealed. The comparison of allele frequencies in groups of cultivars developed in different periods of time (before 1996 and in 1996–2007) has demonstrated appearance of new alleles and change of frequencies of existing alleles at the storage protein loci. The high frequency of cultivars with the wheat-rye 1BL/1RS translocation was detected (about 40%). The wheat rye 1AL/1RS translocation was identified in six cultivars developed in the last decade. Four gliadin alleles, Gli-A1w (a marker for the 1AL/1RS translocation), Gli-A1x, Gli-A1y and Gli-B1x, were proposed for cataloging. The article is published in the original.     

Interactions between <Emphasis Type="Italic">Glu-1</Emphasis> and <Emphasis Type="Italic">Glu-3</Emphasis> loci and associations of selected molecular markers with quality traits in winter wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) DH lines

The quality of wheat depends on a large complex of genes and environmental factors. The objective of this study was to identify quantitative trait loci controlling technological quality traits and their stability across environments, and to assess the impact of interaction between alleles at loci Glu-1 and Glu-3 on grain quality. DH lines were evaluated in field experiments over a period of 4 years, and genotyped using simple sequence repeat markers. Lines were analysed for grain yield (GY), thousand grain weight (TGW), protein content (PC), starch content (SC), wet gluten content (WG), Zeleny sedimentation value (ZS), alveograph parameter W (APW), hectolitre weight (HW), and grain hardness (GH). A number of QTLs for these traits were identified in all chromosome groups. The Glu-D1 locus influenced TGW, PC, SC, WG, ZS, APW, GH, while locus Glu-B1 affected only PC, ZS, and WG. Most important marker-trait associations were found on chromosomes 1D and 5D. Significant effects of interaction between Glu-1 and Glu-3 loci on technological properties were recorded, and in all types of this interaction positive effects of Glu-D1 locus on grain quality were observed, whereas effects of Glu-B1 locus depended on alleles at Glu-3 loci. Effects of Glu-A3 and Glu-D3 loci per se were not significant, while their interaction with alleles present at other loci encoding HMW and LMW were important. These results indicate that selection of wheat genotypes with predicted good bread-making properties should be based on the allelic composition both in Glu-1 and Glu-3 loci, and confirm the predominant effect of Glu-D1d allele on technological properties of wheat grains.     

Allelic variation of the HMW glutenin subunits in Spanish accessions of spelt wheat (Triticum aestivum ssp. spelta L. em. Thell.)

Spelt wheat (Triticum aestivum ssp. spelta L. em. Thell.) is a hulled wheat of Germanic origin that survives at marginal areas in Asturias (Spain). The HMW glutenin subunit composition of 403 accessions of spelt wheat from Spain has been analysed by SDS-PAGE. Three allelic variants were detected for Glu-A1. For the Glu-B1 locus, two of seven alleles detected have not been found before; while four of nine alleles detected for the Glu-D1 are not previously described. Considering the three loci, twenty five combinations were found among all the evaluated lines. This wide polymorphism could be used to transfer new quality genes to wheat, and widen the genetic basis of them. Received: 19 September 2000 / Accepted: 20 October 2000     

Use of recombinant inbred lines of wheat for study of associations of high-molecular-weight glutenin subunit alleles to quantitative traits

Summary The high-molecular-weight glutenin subunits (HMW glutenin), encoded by alleles at homoeologous lociGlu-A1,Glu-B1, andGlu-D1 on the long arms of chromosomes1A,1B, and1D of a set of F₈ random recombinant inbred lines (RIL) derived from the bread wheat cross Anza × Cajeme 71, were classified by SDS-PAGE. Anza has poor breadmaking quality and HMW-glutenin subunits (Payne numbers) null (Glu-A1c), 7+8 (Glu-B1b), and 2+12 (Glu-D1a); Cajeme 71 has good quality and 1 (Glu-A1a), 17+18 (Glu-B1i), and 5+10 (Glu-D1d). The combinations of these alleles in the RIL were examined for associations with grain yield and four indicators of grain quality — protein content, yellowberry, pearling index, and SDS sedimentation volume. Data were obtained from a field experiment with three nitrogen fertilization treatments on 48 RIL and the parents. Orthogonal partitioning of the genetic variance associated with the three HMW glutenin subunit loci into additive and epistatic (digenic and trigenic) effects showed strong associations of these loci with grain yield and the indicators of quality; however, the associations accounted for no more than 25% of the differences between the parents. Genetic variance was detected among the RIL, which had the same HMW glutenin genotype for all traits. Epistatic effects were absent for grain yield and yellowberry, but were substantial for grain protein content, pearling index, and SDS sedimentation volume. All three loci had large single-locus additive effects for grain yield, protein, and SDS sedimentation volume. Yellowberry was largely influenced byGlu-B1 andGlu-D1, whereas pearling index was associated withGlu-A1 andGlu-B1. Even though the observed associations-of effects of HMW glutenin loci with the quantitative characters were small relative to the total genetic variability, they are of considerable importance in understanding the genetics of wheat quality, and are useful in the development of new wheat varieties with specific desired characteristics.     

Comparison of low- and high molecular-weight wheat glutenin allele effects on flour quality

Five crosses were made, using a set of New Zealand wheat cultivars, to measure the effect of glutenin allele differences on baking quality parameters. The alleles involved were: Glu-A1 (2*, 1 and n), Glu-D1 (5+10, 2+12), Glu-A3 (c, d and e), Glu-B3 (Sec-12, Sec-13, b and g), Glu-D3 (a and b). The allelic variation of F₃ individual plants was identified by SDS-PAGE, and plants with the same HMW-GS and LMW-GS patterns were grouped. Quality parameters were then measured on the grouped F₄ bulks. Quality parameters measured for this study were wholemeal flour protein content (WFP), grain hardness (HAR), SDS sedimentation volume (SED), Pelshenke time (PEL), mid-line peak value (MPV) and the mid-line peak time (MPT) of a mixograph. The results showed there were significant quality differences within most populations associated with the possession of a particular allele, reaching magnitudes of up to 42% for the range between populations. Most glutenin allelic comparisons showed significant differences for at least one of the resultant measured quality parameters. Allelic differences of Glu-A1 significantly influenced all characters except MPT, with the null allele apparently inferior; possession of 5+10 at Glu-D1 significantly increased Pelshenke time and SED volumes relative to allele 2+12; WFP, SED and MPV were significantly affected by the Glu-A3 alleles tested. Glu-B3 alleles significantly affected all characters except hardness and the Glu-D3 alleles tested significantly affected all characters other than hardness and SDS sedimentation volume. Received: 8 June 1999 / Accepted: 25 July 2000     

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.     

Genetic Analysis of Chromosomal Loci Affecting the Content of Insoluble Glutenin in Common Wheat

In common wheat, insoluble glutenin(IG) is an important fraction of flour glutenin macropolymers, and insoluble glutenin content(IGC)is positively associated with key end-use quality parameters. Here, we present a genetic analysis of the chromosomal loci affecting IGC with the data collected from 90 common wheat varieties cultivated in four environments. Statistical analysis showed that IGC was controlled mainly genetically and influenced by the environment. Among the major genetic components known to affect end-use quality,1BL/1RS translocation had a significantly negative effect on IGC across all four environments. As to the different alleles of Glu-A1,-B1 and-D1 loci, Glu-A1 a, Glu-B1 b and Glu-D1 d exhibited relatively strong positive effects on IGC in all environments. To identify new loci affecting IGC, association mapping with 1355 DAr T markers was conducted. A total of 133 markers were found associated with IGC in two or more environments(P 0.05), ten of which consistently affected IGC in all four environments. The phenotypic variance explained by the ten markers varied from 4.66% to 8.03%, and their elite alleles performed significantly better than the inferior counterparts in enhancing IGC. Among the ten markers, w Pt-3743 and w Pt-733835 reflected the action of Glu-D1, and w Pt-664972 probably indicated the effect of Glu-A1. The other seven markers, forming three clusters on 2AL, 3BL or 7BL chromosome arms, represented newly identified genetic determinants of IGC. Our work provided novel insights into the genetic control of IGC, which may facilitate wheat enduse quality improvement through molecular breeding in the future.     

湖北推广小麦品种(系)高分子量麦谷蛋白亚基组成分析

应用SDS-PAGE技术分析了45份湖北推广小麦品种(系)籽粒的高分子量麦谷蛋白亚基组成。40份材料的高分子量麦谷蛋白亚基组成为同质,5份为异质。在Glu-1位点共检测到9种等位基因变异类型,其中Glu-A1位点有“1、2^ 、Null”3种变异类型,Glu-B1位点有“7、7 8、7 9、14 15”4种,Glu-D1位点有“2 12、5 10”2种。“Null、7 8、2 12”是主要亚基,它们的频率分别是62．5％、60％和72．5％。亚基组合类型有12种,其中(Null,7 8,2 12)亚基组合占30．0％,(1,7 8,2 12)、(1,14 15,2 12)、(Null,7 9,2 12)、(Null,7 8,5 10)4种组合的频率都在10％以上,这5种亚基组合占总组合的72．5％。供试小麦材料品质评分在5～10之间,平均评分为7．0。含5 10亚基的品种(系)所占比例低,是湖北小麦烘烤品质较差的部分原因。