138份河西地区春小麦种质资源的遗传多样性分析

为了解河西地区小麦种质资源的多样性,选取138份河西地区春小麦种质,分析其A-PAGE醇溶蛋白谱带.供试材料的醇溶蛋白经A-PAGE电泳分析后,共检测到39条谱带,其中33条为多态性条带,多态性条带占84.6％.种质间的Dice相似性系数(GS)为0.222～0.979,波动较大.说明河西地区春小麦种质资源的遗传关系复杂;138份春小麦种质在GS=0.63的水平上可以分为9个UPGAM聚类群,9个聚类群的Shannon多样性指数相对比较均匀,说明在同一类群内种质的多样性比较稳定,第9类群的Shannon多样性指数最小(0.6162),第8类群的变异最大(0.6588).本研究结果表明,河西地区小麦种质资源遗传多样性丰富,有利于河西地区春小麦育种工作.     

醇溶蛋白法和SSR标记法检测小麦种子纯度的比较

为了比较SSR标记法和醇溶蛋白法检测小麦种子纯度的准确度,以参加冬小麦区域试验的8个品系为试材,利用SSR标记法和醇溶蛋白法分别检测8个品系中的杂株,以田间表型鉴定结果为对照.结果表明,在800个单株(每个品系取100个单株)中,醇溶蛋白法和SSR标记法分别检出44和55个杂株,田间表型鉴定出49个杂株.这49个杂株中,有41株同时被SSR标记法和醇溶蛋白法鉴定出来,另有8株仅被SSR标记法鉴定出来.证明SSR标记法检测小麦种子纯度较醇溶蛋白法更加准确.     

河西灌区小麦地方品种醇溶蛋白的遗传多样性分析

为了挖掘小麦地方品种的潜力,采用APAGE方法分析了河西灌区70份小麦地方品种的醇溶蛋白,研究了醇溶蛋白的遗传多样性。结果表明,供试材料中共分离出迁移率不同的醇溶蛋白谱带91条,品种间变异幅度为11～26条,平均为18.33条,变异系数为16.08,具有16、17、19、20条谱带的品种最多。在91条醇溶蛋白谱带中,B01号谱带出现频率最高,为97.14%;B77和B03号谱带出现的频率也较高,分别为92.86%和88.57%。B72和B91号谱带出现频率最低,分别只出现1次,频率均为1.43%。其余谱带多态性很高。在不同分区中醇溶蛋白谱带的分布存在较大差异,ω区出现的谱带最多,β区次之,γ区第三,α区出现的谱带最少。供试材料之间遗传距离的变化范围为0.24～1.00,平均值为0.66。说明河西灌区小麦地方品种间存在丰富的醇溶蛋白遗传多样性,在小麦品质育种中具有一定利用价值。     

Composition of peptide mixtures derived from simulated gastrointestinal digestion of prolamins from different wheat varieties

Gliadin content of wheat is highly variable, both qualitatively and quantitatively, in function of the plant genetic and of the growing conditions. The gliadins are among the major triggers of celiac disease: peptides derived from the gastrointestinal digestion of these proteins and absorbed from the lamina propria cause the immunological reactions that damage the villous structure in affected subjects. In the present work, the peptide mixtures generated by simulated gastrointestinal digestion of the prolamin fraction extracted from different wheat varieties (Triticum turgidum subsp. durum and Triticum aestivum) were characterized by LC/MS and LC-MS/MS techniques. Peptides related to the amount of α-gliadin, as well as toxic and immunogenic peptides for celiac patients have been identified and quantified using an isotopically labeled internal standard. The quantification demonstrated strong differences among the varieties tested. Some samples, belonging to the same varieties and/or cultivation area, showed a lower α-gliadin content, and a smaller amount of toxic and immunogenic peptides.     

Identification of α-gliadin genes in <Emphasis Type="Italic">Dasypyrum</Emphasis> in relation to evolution and breeding

To better understand molecular evolution of the large α-gliadin gene family and provide a potential value for wheat quality improvement, total 32 α-gliadin gene sequences were isolated from the two Dasypyrum species, D. villosum. (L.) Candargy and D. breviaristatum (Lindb. F.) Frederisksen. Twelve of 32 sequences contained the in-frame stop condons were predicted to be pseudogenes, suggesting the high variation of gliadin genes in Dasypyrum genome. There are five D. breviaristatum α-gliadin sequences present additional cysteine residues. Four peptides which have been identified as T cell stimulatory epitopes in celiac disease (CD) patients through binding to HLA-DQ2/8 were searched to all Dasypyrum α-gliadin gene sequences, and we found that the distribution of the epitopes varied between Dasypyrum genomes. Phylogenetic analysis of the Dasypyrum α-gliadin genes indicated that the sequences from D. breviaristatum displayed higher variation than those from D. villosum, and the genomic differentiation occurred between the two Dasypyrum species. Moreover, the promoter region of the Dasypyrum α-gliadin genes consisted of four different lengths, indicative of the retrotransposons involving the evolution of the gliadin gene promoters. Based on the specific sequences of the Dasypyrum α-gliadin promoter region, we produced sequence-characterized amplified region (SCAR) markers, and localized the Dasypyrum α-gliadin genes on chromosome 6 VS. The SCAR markers can be used to target the introgression of Dasypyrum α-gliadin genes in wheat–Dasypyrum derivatives.     

小麦种质资源醇溶蛋白指纹图谱数据库的初步建立及应用

利用ISTA的A-PAGE标准方法,初步建立了我国小麦的主要栽培品种、古老地方品种及国外引进品种共90份材料的标准醇溶蛋白指纹图谱数据库,并利用该数据库对90份供试材料进行了遗传多样性分析及聚类分析,共发现有75条相对迁移率不同的醇溶蛋白谱带,且出现频率不同,表明醇溶蛋白指纹图谱具有丰富的遗传多样性。     

Allelic diversity of HMW and LMW glutenin subunits and omega-gliadins in French bread wheat (Triticum aestivum L.)

Wheat endosperm storage proteins, namely gliadins and glutenins, are the major components of gluten. They play an important role in dough properties and in bread making quality in various wheat varieties. In the present study, the different alleles encoded at the 6 glutenin loci and at 3 -gliadin loci were identified from a set of 200 hexaploid wheat cultivars grown primarily in France using SDS PAGE. At Glu-A1, Glu-B1 and Glu-D1, encoding high molecular weight glutenin subunits (HMW-GS), 3, 8 and 5 alleles were observed respectively. Low molecular weight glutenin subunits (LMW-GS) displayed similar polymorphism, as 5 and 11 alleles were identified at loci Glu-A3 and Glu-B3 respectively. Four alleles were observed at Glu-D3 loci. Omega-gliadin diversity was also very high, as 7, 13 and 9 alleles were found at Gli-A1, Gli-B1 and Gli-D1, respectively. A total of 147 (or 149) patterns resulted from the genetic combination of the alleles encoding at the six glutenin loci (or Glu-1 and Gli-1 loci). Although Glu-1 and Glu-3 loci were located on different chromosome arms and were theoretically independent, some associations were revealed due to pedigree relatedness between some French wheat cultivars. The usefulness of allelic identification of LMW-GS together with HMW-GS and gliadins for future genetic and technological wheat improvement is discussed.     

普通小麦及其近缘种醇溶蛋白遗传多样性分析

为了解小麦近缘种的醇溶蛋白多样性分布规律,应用A-PAGE方法对63份普通小麦及其近缘种材料进行醇溶蛋白遗传多样性分析.结果表明,电泳出现99条迁移率不同的谱带,构成63种组合,总体多态性信息指数达到0.984,以ω区最高,γ和β次之,α区最低.不同基因组构成材料多态性信息指数的分区比较发现,近缘种材料与普通小麦在α区相差最大,其中AA、AABB、AAGG基因组在α区的多态性信息指数均比地方小麦和斯卑尔脱小麦高0.164,而与广泛杂交改良的高代品系类似.谱带分布频率分析发现,高频带和中频带主要出现在ω、γ和β三个区,频率低于0.05的低频带主要出现在α区.聚类分析反映的亲缘关系基本和进化一致,但近缘种与普通小麦高代品系有交叉.此外,本文亦对小麦近缘种的醇溶蛋白分布规律及其在品质育种中的应用潜力进行了讨论.     

小麦新品种川农16与99E18的SSR及贮藏蛋白差异分析

为了更好地识别川农16的遗传基因特性,为充分利用优异材料99E18改良川农16提供理论依据,应用简单重复序列(SSR)标记、酸性聚丙烯酰胺凝胶电泳(A-PAGE)和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)对小麦新品种川农16与高抗优质材料99E18间的遗传差异进行了检测与分析。SSR标记检测结果表明川农16与99E18在DNA水平上存在明显差异。A-PAGE分析显示川农16与99E18间至少有12条醇溶蛋白差异带。SDS-PAGE分析表明川农16和99E18的高分子量谷蛋白亚基组成分别为(1,20．5 10)和(1,7 8,5 10)。     

Immunological analysis of serum for buckwheat fed celiac patients

Buckwheat (Fagopyrum esculentum, Moench), a herbaceous plant of the Polygonaceae family, does not have any affinity for the Gramineae family. It is commercially rated as a cereal, which has led to some misunderstanding concerning its use in gluten induced enteropathy or celiac disease. The effect of buckwheat flour ingestion by celiac patients was evaluated through the indirect immunofluorescence technique. Samples of serum were collected 30 days after the flour ingestion. Cryostat performed cuts of wheat and buckwheat grains were accomplished in order to compare the reactivity of their proteins and serum of celiac and normal patients. The assay revealed that the buckwheat flour presents no toxicity for the celiac patient and no anti-protein antibodies formation in the grain was observed for serum dilutions of 1:2 up to 1:32 with 0.15 M NaCl solution in 0.01 M phosphate buffer, pH 7.2 throughout the 30 day assay period. The results of the immunological assays showed that the buckwheat flour does not present toxic prolamines to celiac disease patients.