To understand the genetic and biochemical basis of the bread makingquality of wheat varieties, a large experiment was carried out with a set of162 hexaploid bread wheat varieties registered in the French or EuropeanWheat Catalogue. This material was used to analyse their allelic compositionat the twelve main storage protein loci. A large genetic and biochemicaldiversity of the gluten proteins was found. Several gliadin encoding lociexhibited the highest allelic diversity whereas the lowest diversity was foundfor Glu-A1 and Glu-D3 loci encoding some high molecularweight glutenin subunits (HMW-GS) and LMW-GS respectively. Thevarieties were grown in three experimental locations in France. Qualityevaluation was carried out from material harvested in each location usingseven technological tests: grain protein content (Prot), grain hardness(GH), Zeleny sedimentation test (Zel), Pelshenke test (Pel), water solublepentosans (relative viscosity: Vr ), mixograph test (giving 11 parameters)and the alveograph test (dough strength W, tenacity P , extensibility L,swelling G, ratio P/L and the elasticity index Ie). Genetic and locationeffects as well as broad-sense heritability of each of the 22 technologicalparameters were calculated. GH, corresponding to the major Ha gene, Pel,and MtxW (mixograph parameter) had the highest heritability coefficients,alveograph parameters like W, P, the relative viscosity Vr and severalmixograph parameters had medium heritability coefficients whereas Protand L had the lowest. Variance analysis (using GLM procedure) allowed theeffect of the allelic diversity of the storage proteins, on the geneticvariations of each quality parameters, to be estimated. Glu-1 and Glu-3 loci had significant additive effects in the genetic variations of manyparameters. Gliadin alleles encoded at Gli-1 and Gli-2 were alsofound to play significant effect on several quality parameters. The majorpart of the phenotypic variation of the different quality parameters like Zel,Pel, W or mixograph peak time MPT was explained with the GH and allelesencoded at Glu-1 and Glu-3 . Allelic variants encoded at Glu3and Gli-2 had similar contribution to the phenotypic variations ofquality parameters and accounted for 4% up to 21% each.

目前小麦育种中普遍存在的问题是种质资源匮乏,改变这种现状最基本、有效的途径之一,是应用理化诱变剂进行诱变育种,即人工诱导产生突变经多代筛选和鉴定,培育高产、优质及综合性状优良的小麦新种质.EMS是一种良好的化学诱变剂,目前已成为在作物诱变育种中应用最广泛、应用效果最好的一种化学变剂.本研究利用不同浓度EMS对小麦品种新春11号籽粒进行诱变处理,确定EMS'适宜诱变剂童,并探讨EMS对小麦产童性状和农艺性状的诱变效应.

Tillering is one of the most important agronomic traits in cereal crops because tiller number per plant determines the number of spikes or panicles per plant, a key component of grain yield and/or biomass. In order to characterize the underlying genetic variation for tillering, we have isolated mutants that are compromised in tillering ability using ethyl methanesulphonate (EMS)-based mutagenesis in diploid wheat ( Triticum monococcum subsp. monococcum ). The tillering mutant, tiller inhibition (tin3 ) produces only one main culm compared to the wild type with many tillers. The monoculm phenotype of tin3 is due to a single recessive mutation. Genetic and molecular mapping in an F 2 population of diploid wheat located the tin3 gene on the long arm of chromosome 3A m . One codominant RFLP marker Xpsr1205 cosegregated with tin3 in the F 2 population. Physical mapping of PSR1205 in a set of Chinese Spring deletion lines of group-3 chromosomes placed the tin3 gene in the distal 10% of the long arm of chromosome 3A, which is a recombination-rich region in wheat. The implications of the mapping of tin3 on chromosome arm 3A m L are discussed with respect to putative orthologs of tin3 in the 3L colinear regions across various cereal genomes and other tillering traits in grasses.

Different concentrations of EMS were injected to wheat spikes at the early prophase stage of meiosis.The results indicated that both chromosomal aberration frequency (CAF) and micronuclic frequency (MF) were increased significantly by the treatments.The two parameters were parel-lel to each other, which suggest that it is possible to use MF instead of CAF as the indicator of mutationlesions.The influence of EMS treatments on callus induction frequency (CIF) and plantlet regeneration frequency (PRF) of anther culture in vitro is also reported. It was found that with lower concentrations of EMS(0.1%), the CAF is considerably high while the CIF is low.The higher concentrations of EMS treatments could decrease the PRF of callus and increase the proportion of albino plantlets of the regenerated population. Similar reactions to EMS treatments for different spring wheat cultivars indicated that the effect of FMS is specific.

本实验采用注射法,以不同浓度的甲基磺酸乙酯(EMS)处理春小麦活体植株的幼穗,染色体畸变率和微核率明显提高,而且两者的变化有平行性,再次证明在植物上用微核技术代替染色体畸变分析检测诱变损伤是可行的。本实验还通过花药培养,探讨了这种诱变处理对花粉愈伤组织诱导和幼苗分化的影响,观察到EMS在0.1—0.2％浓度下,染色体畸变率高,而出愈率低,高浓度EMS处理降低了愈伤组织的幼苗分化率,并使白苗数增多。经分析,不同春小麦品种对EMS的反应基本一致,说明EMS的作用有一定的专一性。

【Objective】 The mutant library is the basic material of functional genomics. In wheat, this kind of mutant library was rarely reported. In this study, two wheat mutant libraries with EMS were constructed for laying a foundation for wheat functional genomics research. 【Method】 EMS was used as chemical mutagen to build the mutant library with early mature spring wheat Yanzhan 4110. Biological characters and agronomic traits were investigated in M2 generation. Some of mutants identified from M2 plants will be validated through M3 generation. 【Result】 During the growth period after sowing the M2 seeds, all the phenotypic changes of plants were observed and recorded. Phenotype mutants such as seedling habits, leaf appearance, plant height, spike appearance and mature period were obtained. Some of them were related to important agronomic traits and biological characters, specifically, some mutants were rarely observed in natural variation, such as extremely dwarf, with plant height at about 10-15cm. The rate of M2 phenotype mutation was 6.6%. 【Conclusion】 Two libraries of Yanzhan 4110 induced with EMS are ideal mutant libraries and they will be efficiently used in wheat functional genomic research and wheat improvement.

【目的】构建小麦EMS突变体库，为小麦功能基因组学研究准备基础材料。【方法】利用化学诱变剂甲基磺酸乙酯（ethyl methane sulfonate，EMS）诱变处理小麦品种偃展4110种子，将获得的M2代材料进行生物学性状与农艺性状鉴定，部分M3材料播种家系进行验证。【结果】对M2代全生育期田间表型进行观察鉴定，突变群体的表型变异率约为6.6%；获得了幼苗、叶、茎、穗及成熟期等生物学特性与主要农艺性状的变异体和突变体，变异类型丰富，特别是发现了自然突变中少见的变异类型，如株高在10-15 cm左右的特矮变异类型。【结论】本研究所构建的两个偃展4110 EMS突变群体较为理想，可望有效地被用于小麦功能基因组研究和小麦遗传改良中。

Allelic variations at the Glu-1 and Glu-3 loci play an important role in determining dough properties and bread-making quality. Two hundred and fifty-one cultivars and advanced lines from four major Chinese wheat-producing zones in the autumn-sown wheat regions were used to investigate the high-molecular-weight glutenin subunits (HMW GS) and low-molecular-weight glutenin subunit (LMW GS) composition controlled by the Glu-1 and Glu-3 loci, respectively, as well as the presence of the 1B.1R translocation, and to determine the association of storage protein composition with protein content, SDS sedimentation value, and dough-mixing properties measured by mixograph. Three, nine, and four allelic variations were present at Glu-A1 , Glu-B1 , and Glu-D1 , respectively. Subunits 1, N, 7+8, 7+9, and 2+12 are the dominant HMW GS, with frequencies of 51.3, 39.4, 38.2, 45.0, and 59.8%, respectively. Five and eight allelic variations were present at the Glu-A3 and Glu-B3 loci (data of Glu-D3 were not available), Glu-A3a , Glu-A3d , Glu-B3j (presence of the 1B.1R translocation), and Glu-B3d are the dominant LMW GS, with frequencies of 37.1, 31.7, 44.6, and 20.3%, respectively. The frequencies of allelic variation at Glu-1 and Glu-3 differ greatly in different regions. The effects of HMW GS and LMW GS on SDS sedimentation value, mixing time, and mixing tolerance were significant at P = 0.01, with Glu-D1 and Glu-B3 showing the largest contributions to mixing time and mixing tolerance. Averaged data from two locations showed that the quality effects of glutenin loci could be ranked as Glu-B3 > Glu-B1 > Glu-A1 > Glu-D1 > Glu-A3 for SDS sedimentation value, Glu-D1 > Glu-B3 > Glu-A1 = Glu-B1 = Glu-A3 for mixing time, and Glu-D1 > Glu-B3 = Glu-B1 > Glu-A3 > Glu-A1 for mixing tolerance, respectively. The significant and negative effect of the 1B.1R translocation on dough properties was confirmed. It was concluded that the high frequency of undesirable HMW GS and LMW GS and the presence of the 1B.1R translocation are responsible for the weak gluten property of Chinese germplasm; hence, reducing the frequency of the 1B.1R translocation and integration of desirable subunits at Glu-1 and Glu-3 such as 1, 7+8, 14+15, 5+10, Glu-A3d , and Glu-B3d , could lead to the improvement of gluten quality in Chinese wheats.

高分子量麦谷蛋白是小麦种子贮藏蛋白的重要组成部分,其数量和质量对小麦面筋含量及面粉烘烤品质有直接影响.因此,小麦高分子量麦谷蛋白基因的表达与沉默备受关注.本文主要介绍了高分子量麦谷蛋白基因沉默材料的发现及其沉默机理的研究现状,认为小麦高分子量麦谷蛋白基因沉默包括两种情况即在一个基因座位上所有编码基因均不表达和只有一个编码基因不表达.第一种情况可能是染色体部分缺失的结果,有时也被认为是由于调控元件发生了突变;而基因突变即DNA调控序列和/或编码区的微小缺失及其他变化则可能是第二种情况发生的机制.本文还简要介绍了离子束生物技术、转基因技术、化学诱变、组织培养等可以用于创制基因沉默材料的技术. Abstract： The high-molecular-weight glutenin subunits (HMW-GSs) are a major class of storage proteins in wheat. The end-use quality of wheat flour is directly influenced by the composition and quantity of HMW-GSs. Therefore, researchers pay more attention to the gene silencing of them. In this article, we give a brief introduction of the development of HMW glutenin gene silence material and the mechanism of gene silencing. We think that the gene silencing of wheat HMW-GSs included two cases: all of the coding genes are silencing and only one coding gene is silencing in a gene locus. The first case may be caused by partial deletion of chromosome, or mutations of regulatory elements sometimes. The second is probably because of gene mutation, such as deletion and other changes of DNA regulatory sequence and / or coding region. Several gene silencing techniques, including of Ion Beam Bio-technology, transgene technology, Chemical Mutagenesis, Tissue Culture, and so on, are also illustrated.

本文简述了作物诱发育种的发展现状,重点介绍了当今应用最广泛的电离辐射和化学诱变的原理其及在作物育种上的最新研究成果。

简要叙述了甲基磺酸乙酯(EMS)诱导小麦突变体最佳诱变剂量的选择,突变材料的种植及其选择的方法,阐述了出现的变异类型和突变体的应用,并对今后的进一步研究进行了展望.

The Hardness ( Ha ) locus controls grain texture and affects many end-use properties of wheat ( Triticum aestivum L.). The Ha locus is functionally comprised of the Puroindoline a and b genes, Pina and Pinb , respectively. The lack of Pin allelic diversity is a major factor limiting Ha functional analyses and wheat quality improvement. In order to create new Ha alleles, a 630 member M 2 population was produced in the soft white spring cultivar Alpowa using ethylmethane sulfonate mutagenesis. The M 2 population was screened to identify new alleles of Pina and Pinb . Eighteen new Pin alleles, including eight missense alleles, were identified. F 2 populations for four of the new Pin alleles were developed after crossing each back to non-mutant Alpowa. Grain hardness was then measured on F 2:3 seeds and the impact of each allele on grain hardness was quantified. The tested mutations were responsible for between 28 and 94% of the grain hardness variation and seed weight and vigor of all mutation lines was restored among the F 2 populations. Selection of new Pin alleles following direct phenotyping or direct sequencing is a successful approach to identify new Ha alleles useful in improving wheat product quality and understanding Ha locus function.

We report the use of TILLING (targeting induced local lesions in genomes), a reverse genetic, nontransgenic method, to improve a quality trait in a polyploid crop plant. Waxy starches, composed mostly of amylopectin, have unique physiochemical properties. Wheat with only one or two functional waxy genes (granule-bound starch synthase I, or GBSSI) produces starch with intermediate levels of amylopectin. We have identified 246 alleles of the waxy genes by TILLING each homoeolog in 1,920 allohexaploid and allotetraploid wheat individuals. These alleles encode waxy enzymes ranging in activity from near wild type to null, and they represent more genetic diversity than had been described in the preceding 25 years. A line of bread wheat containing homozygous mutations in two waxy homoeologs created through TILLING and a preexisting deletion of the third waxy homoeolog displays a near-null waxy phenotype. This approach to creating and identifying genetic variation shows potential as a tool for crop improvement.

Improvement of end-use quality has become a major breeding objective in China. In order to further improve gluten quality, effective selection parameter in early generation is necessary in wheat quality breeding program. In total, 108 wheat ( Triticum aestivum L.) varieties and advanced lines were used to test kernel hardness, protein content, sedimentation value, mixogragh parameters, glutenin polymeric protein content by biuretium protein fraction procedure, and the amount and ratio of gluten protein fractions by size-exclusion high-performance liquid chromatography method (SE-HPLC). The relationship between flour protein content, sedimentation volume, and mixograph parameters and gluten protein fractions in quantity were investigated. The results showed that broad variations for quality traits and quantitativedata for protein fractions were observed in this set of germplasm. The range of mixograph peak time was 1.12–7.19 min, and the range of SDS-unextractable polymeric protein was very broader than that of SDS-extractable polymeric protein. There were less correlation between grain hardness, flour protein content, whole meal sedimentation value, and mixograph peak time with r of 0.24–0.49. The amount of gliadin was not significantly correlated with mixograph parameters, while the ratio of gliadin to glutenin (Gli/Glu) was crucial in determining mixograph parameters [r = (–0.52)– (–0.61), P＜0.001], which was independent of flour protein content. The strong associations between percent SDS-unextractable fraction in total polymeric protein (%UPP) and mixograph parameters were observed with r of 0.70–0.85 (P＜0.001). %UPP and Gli/Glu tested by SE-HPLC can be used as effective parameters for early generation selection to improve wheat gluten strength due to their automatic micro-analyzing method.

选用品质差异较大的108份主栽品种和高代品系, 测定其谷蛋白聚合体总量(双缩脲法)和贮藏蛋白组分含量及比例(凝胶色谱法, SE-HPLC), 并分析了它们与蛋白质含量、沉降值以及和面仪参数等早代选择参数的相关性。结果表明, 参试材料品质特性和贮藏蛋白组分含量的变异范围都较大。和面仪峰值时间变异范围为1.12~7.19 min, 变幅达6.07 min; 醇溶蛋白总量和SDS可溶性谷蛋白聚合体(EPP)变幅较小, 而SDS不溶性谷蛋白大聚体(UPP)的变幅最大。硬度、蛋白质含量和沉降值与和面峰值时间的相关系数较低(r=0.24~0.49)。醇溶蛋白总量与和面仪参数相关不显著, 而与谷蛋白总量的比值(Gli/Glu)与和面仪参数呈显著负相关(r= –0.52~ –0.61, P＜0.001), 且不受蛋白质含量的影响。SDS不溶性谷蛋白大聚体百分含量(%UPP)与和面仪参数的相关性最高, 相关系数为0.70~0.85(P＜0.001)。SE-HPLC法样品用量少, 自动化程度高, 且%UPP和Gli/Glu为相对值, 与和面仪参数呈高度相关, 可作为面筋强度早代选择的有效指标。

Abstract The effect of hydrostatic pressure (0.1–800 MPa) in combination with various temperatures (30–80 °C) on the chemical and physical properties of wheat gluten, gliadin and glutenin was studied. Chemical changes of proteins were determined by extraction, reversed-phase high-performance liquid chromatography (HPLC), sodium dodecylsulphate (SDS) polyacrylamide gel electrophoresis (PAGE), circular dichroism (CD) spectroscopy, thiol measurement and studies on disulphide bonds. Rheological changes were measured by extension tests and dynamic stress rheometry. Treatment of gluten with low pressure (200 MPa) and temperature (30 °C) increased the proportion of the ethanol-soluble fraction (ESF) and decreased gluten strength. The enhancement of both pressure and temperature provoked a strong reduction of the ESF and the thiol content of gluten. Within gliadin types, cysteine containing α - and γ -gliadins, but not cysteine-free ω -gliadins were sensitive to pressure and were transferred to the ethanol-insoluble fraction. Disulphide peptides isolated from treated gluten confirmed that cleavage and rearrangement of disulphide bonds were involved in pressure-induced reactions. Increased pressure and temperature induced a significant strengthening of gluten, and under extreme conditions (e.g. 800 MPa, 60 °C), gluten cohesivity was lost. Isolated gliadin and glutenin reacted differently: solubility, HPLC and SDS-PAGE patterns of gliadin having a very low thiol content were not influenced by pressure and heat treatment; only conformational changes were detected by CD spectroscopy. In contrast, the properties of isolated glutenin having a relatively high thiol content were strongly affected by high pressure and temperature, similar to the effects on total gluten.