小麦高压诱变后代醇溶蛋白变异分析及其对品质性状的影响

为了验证高压诱变对小麦品质改良的有效性,利用酸性聚丙烯酰胺凝胶电泳(A-PAGE)分析了39份小麦高压诱变后代的醇溶蛋白遗传变异情况,并测试了小麦高压诱变后代的理化品质和面团流变学特性.结果表明,39份高压诱变材料出现24条迁移率不同的电泳谱带,与对照相比共有6条迁移率不同的谱带;发生的变异可分为三大类,共37种,变异率达94.8％,变异主要发生在ω和γ区,6条变化的谱带均与8项品质性状相关显著或极显著.总体趋势是当经过高压诱变之后,醇溶蛋白谱带数总量减少,但是部分面团相关品质提高.     

波兰小麦对普通小麦醇溶蛋白的改良作用

为研究波兰小麦对普通小麦醇溶蛋白的改良作用,利用酸性聚丙烯酰胺凝胶(A-PAGE)电泳技术对60个波兰小麦×普通小麦中13后代株系的醇溶蛋白位点进行了检测.结果表明,波兰小麦与普通小麦杂交后代醇溶蛋白存在丰富的变异类型,共产生了34条迁移率不同的醇溶蛋白谱带,其中,α区2条,β区24条,γ区4条,ω区4条.每个株系具有7～21条带,多数株系为12～19条,平均15.68条.醇溶蛋白遗传多样性指数(H')及多态性信息含量(PIC)分析结果显示,β区醇溶蛋白组成最为丰富,而α区最低.供试材料间存在较大的遗传变异,在GD值0.38水平上可聚为4类.波兰小麦醇溶蛋白谱带在BC<,1F<,2中出现的频率比BC<,2中更高,变异更为丰富.杂交后代中出现了4条双亲不具有的新谱带.分析表明,波兰小麦对普通小麦醇溶蛋白的改良有十分明显的作用.     

小麦醇溶蛋白多肽和高分子与低分子麦谷蛋白亚基的两步电泳分析法

以往确定小麦醇溶蛋白和高分子及低分子麦谷蛋白的亚基组分,需要3个独立的单向电泳分离过程.本文所述及的方法只需要两个电泳步骤.用2-氯乙醇提取蛋白质之后,先在酸性条件下进行聚丙烯酰胺凝胶电泳(A-PAGE)分离,测定麦醇溶蛋白组分.然后,将位于A-PAGE凝胶板点样槽紧下面的几个毫米内的非还原聚合蛋白经过还原并用SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)分离,这些蛋白质便可产生反映麦谷蛋白高分子和低分子亚基特性的多肽模式.     

低能离子束介导外源DNA转入小麦种胚中对小麦幼苗叶片蛋白水解酶酶谱的影响

利用低能离子束介导法将大豆DNA导入小麦种子胚中，通过复性电泳技术分析了受体小麦幼苗叶片中蛋白水解酶的变化，结果表明：（1）离子束介导大豆DNA片段的小麦幼苗叶片的蛋白水解酶酶谱有明显变化，出现45和280kD两条新的酶带；（2）小麦幼苗叶片中45和205kD蛋白水解酶的活性受环境影响较大；（3）68和72kD两条酶带在各处理的不同 pH条件下均具较强活性；（4）不同pH条件下蛋白水解酶酶谱变化明显。     

离子束诱导小偃81突变系麦谷蛋白和醇溶蛋白遗传变异分析

摘要：本实验以N+（30Kev）注入诱导获得的小偃81突变系M4代种子为材料,采用SDS-PAGE和A-PAGE技术对其高分子量麦谷蛋白亚基和醇溶蛋白进行系统分析,检测到3个高分子量麦谷蛋白亚基缺失系：1Ax1缺失系,1Bx14+1By15缺失系,1Dx2+1Dy12缺失系,出现频率由大到小依次为1Ax1＞1Bx14+1By15＞1Dx2+1Dy12。醇溶蛋白方面共检测到5种变异类型,1Ax1缺失系有3种突变类型,1Bx14+1By15缺失系和1Dx2+1Dy12缺失系各有1种突变类型,ω区变异类型最多,其次是α区和γ区,β区没有发现变异类型,在5种变异类型中有一条相同的变异谱带。结果表明：N+（30Kev）离子束注入能有效地诱导小麦种子高分子量谷蛋白亚基和醇溶蛋白的变异,并能够在后代中稳定遗传。     

抗赤霉病小麦地方品种的贮藏蛋白分析

采用A-PAGE和SDS-PAGE方法,对来自不同地方的23个抗赤霉病小麦地方品种的醇溶蛋白和谷蛋白亚基进行了分析。结果表明,在A-PAGE电泳分析中,23个供试品种具有23种不同的醇溶蛋白带型,共分离出39条相对迁移率不同的谱带,其中31条具有多态性,占86.8％,每份材料可电泳出14～23条带,存在着广泛的等位基因变异。在SDS-PAGE电泳分析中,出现了9种不同的高分子量谷蛋白亚基及6种亚基组合类型,优质亚基及亚基组合所占的比例较少,品质评分较低,其变幅为5～9分,平均为6.8分。     

部分普通小麦醇溶蛋白的遗传多样性分析

为了揭示普通小麦(Triticum aestivum L.)品种间醇溶蛋白的遗传多样性,采用A-PAGE方法对60份普通小麦品种(系)进行了醇溶蛋白分析.结果表明,全部供试品种(系)共检测到943条带,每份材料可电泳出9～21条带,平均15.7条.试验共获得迁移率不同的谱带74条,其中第2和第4条谱带出现的频率最高,分别为45.00%和、51.67%,其余的谱带多态性很高,说明小麦种质间存在丰富的醇溶蛋白遗传异质性.供试材料间的遗传距离(Genetic distance,GD)变异范围为0.40～0.84,平均为0.62.聚类分析在GD值为0.82水平上可将供试材料分为4大类群.     

离子束介导大豆DNA的小麦变异株系蛋白水解酶谱分析

为研究离子束介导大豆DNA的小麦变异株系在返青期、起身期和拔节期的蛋白水解酶变化．采用复性电泳对新乡9号和筛选出的高蛋白变异株系05—10-1和低蛋白变异株系05—6-1，做不同酸碱条件下的蛋白水解酶分析。结果显示．与对照相比。变异株系05-6—1在返青期酸性条件下少检测到一条29kD酶带；在起身期中性和碱性条件下少检测到一条49kD酶带：在拔节期碱性条件下多检测到一条154kD新酶带．而少检测到158kD的酶带：而变异株系05～10—1在这3个生理时期和对照的蛋白水解酶酶谱带型基本一致．主要在某些酶带的酶活上存在差异。     

低能离子束介导转基因小麦叶片蛋白指纹分析

用SDS－PAGE电泳方法研究了低能离子束介导转大豆DNA小麦灌浆期叶片中蛋白图谱变化，结果表明，离子束介转基因小麦部分个体的叶片蛋白图谱与对照有显著差异，各处理的蛋白图谱中，带型变化主要集中在157，104，83，36，35，34，28和23kD等条带；相对稳定的蛋白质条带分别为47，44，41，40，39，31和24kD。各处理间蛋白图谱存在一定的差异。导入DNA时间对蛋白质图谱有显著影响。     

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.     

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。     

Nutritive value of protein fractions extracted from soybean,rapeseed and wheat flours in the rat

The nutritive value of various protein fractions was studied. Fractions 2S and 12S from rapeseed, 2S, 7S and 11S from soybean were obtained by dissolution in ammonium sulfate solutions. Albumin-globulin, gluten, glutenin and gliadin fractions from wheat were obtained by dissolution in salted water (albumin-globulin), acetic acid (glutenin) and alcohol (gliadin). Liveweight gains, protein efficiency ratio (PER) and apparent digestibility coefficient (ADC) were used as measures of the nutritive value. The protein fractions had a lower nutritive value than the unfractionated proteins except for the albumin-globulin fraction of wheat which had a nutritive value higher than that of the unfractionated wheat protein. PER obtained with the rapeseed 2S and 12S fractions were 2.49 and 2.21, respectively, as compared to 2.64 for unfractionated rapeseed. With soybean fractions, PER were 0.92 for 2S, — 0.007 for 7S and 1.47 for 11S, as compared to 2.19 for the original protein. The wheat albumin-globulin fraction gave a PER of 2.78, as compared to 1.45 for the unfractionated wheat protein. Gluten, glutenin and gliadin fractions had a lower PER than that of unfractionated wheat protein. ADC of all fractions were higher than those of the original proteins. The difference in liveweight gains and PER observed between protein fractions can be partially explained on the basis of the essential amino acid content.     

Rheological Behaviour of Wheat Glutens at Small and Large Deformations. Effect of Gluten Composition

Glutens derived from two wheat cultivars with a known difference in bread making quality, i.e. cv. Katepwa (good) and cv. Obelisk (poor), were fractionated into gliadin and glutenin. Cultivar Katepwa gluten contained more glutenin than cv. Obelisk gluten. Reconstituted glutens were prepared by mixing, in different ratios, gliadin and glutenin fractions that originated from one gluten type or from both glutens. The rheological properties of these mixtures, when hydrated, were studied at small deformations in shear and at large deformations in biaxial extension. The reconstitution of gluten in its original glutenin/gliadin ratio produced a composite that had a somewhat higher resistance to deformation and was more elastic than the unfractionated gluten. This was true for both gluten types. However, the difference between the rheological behaviour of both reconstituted gluten types was comparable with that found between the native glutens. From measurements with glutens reconstituted at various glutenin/gliadin ratios, it appeared that the main factor determining the rheological behaviour of hydrated gluten is the glutenin/gliadin ratio. By interchanging the gliadin and glutenin fractions of the two glutens, it was shown that the source from which the fractions originated, particularly that of the glutenin fraction, was also important.     

Effects of gamma-irradiation of wheat on gluten proteins

The effects of ⁶⁰Co gamma-irradiation treatments (2·5, 5·0, 10·0 and 20·0 kGy) on the gluten proteins of two bread wheats and one durum wheat cultivar were investigated. Dough rheological properties of the flour processed from the irradiated wheat were also determined using a computerised micromixograph. Irradiation caused a significant deteriorating effect on all mixogram parameters. There was no observable effect of irradiation on gliadin proteins analysed by polyacrylamide gel electrophoresis. The 50% 1-propanol-insoluble (50 PI) glutenin fraction was highly affected by irradiation. By sodium dodecyl sulfate polyacrylamide gel electrophoresis, reduced 50 PI glutenin showed a noticeable reduction in band intensities of both high (HMW) and low molecular weight (LMW) glutenin subunits (GS) with increasing irradiation dosage greater than 5 kGy. The irradiation effect on 50 PI glutenin was further studied and quantified by reversed-phase high-performance liquid chromatography of glutenin subunits; there was a progressive decrease in the quantity of subunits with increasing irradiation dose level. Compared to non-irradiated wheat, the relative decline in total insoluble glutenin at the 20 kGy dosage level ranged from 34–49% depending on cultivar. Increasing levels of irradiation also progressively reduced the ratio of HMW:LMW-GS up to 13–15% at 20 kGy indicating that irradiation had a greater effect on the largest polymers of glutenin. The observed weakening of dough mixing properties and concomitant decline in the quantity of 50 PI glutenin with increasing levels of gamma-irradiation are consistent with a degradation of glutenin to a lower average molecular size by depolymerisation and/or disaggregation.     

Using the Gluten Peak Tester as a tool to measure physical properties of gluten

The functional properties of wheat are largely dictated by composition and interactions of the gluten proteins. All flours contain gliadin and glutenin, but produce baked products of varying quality, which provides evidence that gluten proteins from different wheats possess different properties. A common method to study differences in gluten properties, which is utilized in this study, is fractionation/reconstitution experiments to understand how various gliadin to glutenin ratios and how fractions from different wheat sources affect gluten aggregation properties. Gliadin and glutenin from a vital wheat gluten were fractionated with 70% ethanol and reconstituted at various gliadin to glutenin ratios. Gliadin and glutenin from a Canadian eastern soft, eastern hard and western hard wheat (14% moisture) were fractionated and substituted between flours at the native gliadin to glutenin ratio. Gluten combinations were evaluated with a Gluten Peak Tester at constant temperature and mixing. Varying gliadin to glutenin ratio showed that 50:50 is optimal for fast gluten aggregation while amount of glutenin dictates strength. Substitution experiments showed that replacing good quality gluten fractions with those from a lower quality wheat decreases gluten quality, and vice versa. Data also showed that cultivar specific differences in gliadin and glutenin are more important in dictating gluten strength (torque), while gliadin to glutenin ratio dictates aggregation time (PMT) independent of the source of fractions. The study demonstrated the ability of the improved method to evaluate gluten aggregation by controlling for all variables except the one being tested. The data also revealed information about gluten aggregation properties never before seen.     

Using the Gluten Peak Tester as a tool to measure physical properties of gluten

The functional properties of wheat are largely dictated by composition and interactions of the gluten proteins. All flours contain gliadin and glutenin, but produce baked products of varying quality, which provides evidence that gluten proteins from different wheats possess different properties. A common method to study differences in gluten properties, which is utilized in this study, is fractionation/reconstitution experiments to understand how various gliadin to glutenin ratios and how fractions from different wheat sources affect gluten aggregation properties. Gliadin and glutenin from a vital wheat gluten were fractionated with 70% ethanol and reconstituted at various gliadin to glutenin ratios. Gliadin and glutenin from a Canadian eastern soft, eastern hard and western hard wheat (14% moisture) were fractionated and substituted between flours at the native gliadin to glutenin ratio. Gluten combinations were evaluated with a Gluten Peak Tester at constant temperature and mixing. Varying gliadin to glutenin ratio showed that 50:50 is optimal for fast gluten aggregation while amount of glutenin dictates strength. Substitution experiments showed that replacing good quality gluten fractions with those from a lower quality wheat decreases gluten quality, and vice versa. Data also showed that cultivar specific differences in gliadin and glutenin are more important in dictating gluten strength (torque), while gliadin to glutenin ratio dictates aggregation time (PMT) independent of the source of fractions. The study demonstrated the ability of the improved method to evaluate gluten aggregation by controlling for all variables except the one being tested. The data also revealed information about gluten aggregation properties never before seen.     

小麦贮藏蛋白特性及其遗传转化

小麦籽粒贮藏蛋白由醇溶蛋白和谷蛋白组成。醇溶蛋白在组成上以单体形式存在 ,具有高度的异质性和复杂性。它决定小麦面筋的粘性。谷蛋白是由多个亚基组成的高分子聚合体 ,决定面筋的弹性。它可分为低分子量谷蛋白亚基和高分子量谷蛋白亚基 (HMW- GS)。HMW- GS具有相似的分子结构 ,即由中央重复序列、无重复的 N端和 C端组成。HMW- GS对小麦烘烤品质起着决定性作用 ,但因 HMW- GS类型不同而对加工品质的贡献大小各异。许多 HMW- GS基因已被揭示。实践证明 ,利用基因枪法 ,将 HMW- GS基因导入普通小麦的细胞核内 ,能够达到改良小麦烘焙品质的目的。随着分子生物学技术的不断发展 ,可望从营养和加工角度来改良小麦品质的特性     

21份印度小麦高分子谷蛋白亚基、醇溶蛋白及品质分析

为挖掘优良的小麦种质资源,以引进的21份印度小麦种质为材料,利用SDS-PAGE和A-PAGE技术,分析了其高分子量谷蛋白亚基和醇溶蛋白组成。结果表明,在21份印度小麦材料中出现了12种HWM-GS亚基类型和14种亚基组合,其中有3种亚基类型(Null、1、2*)在Glu-A1位点,4种亚基类型(7+8,17+18,7,7+9,13+16)在Glu-B1位点,4种亚基类型(5+10,2+12,4+12,5+12)在Glu-D1位点。1、2+12优质亚基的比例相对较高,均为47.6%。小麦HWM-GS亚基组合1/7+9/2+12在所有亚基组合类型中出现频率高达19.0%。大多数材料的品质得分为7、8分,平均7.52分。共分离出32种迁移率不同的醇溶蛋白谱带,2和3号带出现频率最高,分别为95.24%和90.48%。DA 7200近红外分析仪初步分析结果表明,这21份印度小麦种质资源品质指标相对偏低。