两种浊化剂在小麦谷蛋白大聚合体测定中的有效性

为比较两种浊化剂5-磺基水杨酸-无水硫酸钠（SSA-SS）和三氟乙酸（TCA）在比浊法测定小麦谷蛋白大聚合体（GMP）含量中的有效性,选用黄淮冬麦区有代表性的4个强筋小麦品种和4个中弱筋小麦品种组配的杂种F2代面粉为材料,采用1％DTT的50％正丙醇溶液提取GMP,分别用浊化剂SSA-SS和TCA浊化,再用酶标仪（波长540nm）连续（10～90min）测定不同基因型小麦的GMP提取液的吸光值。结果表明：（1）以SSA—SS为浊化剂时,牛血清蛋白浓度与吸光值的直线回归关系极其密切（r=0．9980）;以TCA为浊化剂时,牛血清蛋白浓度与吸光值的直线回归关系较差。（2）以SSA-SS为浊化荆时,各种基因型小麦GMP提取液的吸光值在30min内具有较好的稳定性;以TCA为浊化剂时,各种基因型小麦GMP提取液的吸光值随时间不断增加。说明比浊法测定小麦GMP含量时,以SSA-SS为浊化剂,加样振荡后10～30min内测定的结果最为稳定。     

春小麦陇春22号抗旱性鉴定及高分子量麦谷蛋白亚基分析研究

陇春22号是从墨西哥国际玉米小麦改良中心引进,历经10年,进一步筛选的优质抗锈春小麦新品种,多年田间鉴定表现抗旱性强,品质优良。为了进一步确定其抗旱性和品质特性,对该品种在干旱条件下的形态特征、生理生化指标、田间产量指标、优质亚基进行了初步的鉴定评价。结果表明:陇春22号萌芽期、幼苗期以及成熟期抗旱性强,含有17 18、5 10优质亚基,适合在甘肃及宁夏等地的干旱半干旱地区大面积推广种植。     

Changes in bread-making quality attributes of bread wheat varieties cultivated in Spain during the 20th century

Genetic gains in quality traits were assessed in grain samples from 4 field experiments involving 16 bread wheat varieties representative of those most widely cultivated in Spain during the 20th century. The allelic composition at three glutenin loci (Glu-A1, Glu-B1, and Glu-D1) was obtained by PCR-based DNA markers and published references. From 1930 to 2000 grain protein content decreased by −0.030% y⁻¹, or in relative terms by −0.21% y⁻¹, but the protein produced per hectare increased by 0.39% y⁻¹. Alveographic tests revealed significant changes in dough rheological properties. Dough strength (W) and tenacity (P) increased at relative rates of 1.38% y⁻¹ and 0.99% y⁻¹, respectively, while dough extensibility (L) decreased by −0.46% y⁻¹, resulting in an increase of 1.45% y⁻¹in dough equilibrium (P/L). The rise in protein quality could be related to the replacement of the null allele by subunits 1 or 2* at Glu-A1 and the prevalence of subunits 7 + 8 and 5 + 10 at Glu-B1 and Glu-D1 loci, respectively, in the most recent varieties. Dough extensibility was affected by water input during the crop cycle, this relationship being partially explained by the presence of the 5 + 10 HMW glutenin subunit. Fermentation tolerance was improved in the most modern varieties. Collapse during fermentation was avoided only in doughs with a W ≥ 159 J × 10⁻⁴ and a P/L ≥ 0.56 mm H₂O mm⁻¹, levels achieved by most of the modern varieties. The over-strong and unbalanced rheological properties of some modern varieties resulted in highly porous doughs, and no clear advances in dough maximum height during fermentation were attained.     

甘肃小麦品种(系)HMW-GS遗传变异分析

为了了解甘肃省小麦品种HMW-GS的遗传变异和组成，为甘肃优质专用小麦品种筛选和品种改良提供依据,采用SDS-PAGE法，分析了254份甘肃省小麦材料(育成品种(系)和农家品种)Glu-1位点的HMW-GS变异，共检测到22种HMW-GS变异，Glu-A1位点3种，Glu-B1位点11种，Glu-D1位点8种。其中110个育成品种(系)的15种HMW-GS有27种亚基组合类型。Glu-A1位点有2种亚基，47．3％的品种该位点具有优质亚基；Glu-B1位点有7种亚基，76．4％的品种具优质亚基；Glu-D1位点有6种亚基，32．7％的品种具优质亚基。14．5％的品种(n：15)Glu-1位点具优质亚基。144份农家品种的18种HMW-GS共有29种亚基组合形式，Glu-A1位点有3种亚基,Glu-B1位点有9种亚基，Glu-D1位点有6种亚基，无优质亚基组合。     

二倍体长穗偃麦草高分子量谷蛋白亚基多态性研究

二倍体长穗偃麦草(Thinopyrum elongatum)E组染色体携带有对小麦遗传育种有益的基因。通过SDS-PAGE，分析了9份二倍体长穗偃麦草的高分子量谷蛋白亚基类型，初步发现有6种等位变异类型，显示了二倍体长穗偃麦草E组染色体携带有丰富的高分子量谷蛋白亚基(HMW-GS)等位基因类型，是普通小麦进行品质改良的重要基因资源。     

小麦2+12和5+10亚基近等基因系间面粉品质差异的研究

分析和研究了小麦栽培品种克旱九、垦大四和龙麦20的高分子量麦谷蛋白亚基(HMW-GS)近等基因系的面粉品质. 这些近等基因系是通过5～6次连续的选择性回交获得的. 结果表明, 在蛋白质和干面筋含量上, 近等基因系间的差别不显著. 在湿面筋与干面筋的比值(湿面筋/干面筋)上5+10亚基的近等基因系比带有2+12亚基的近等基因系要小4.7     

Breeding for end-use quality: Reflections on the Nebraska experience

Every cultivar released in Nebraska must have four characteristics:improved agronomic performance relative to existing cultivars, exceptionalwinterhardiness, resistance to Puccinia graminis (the causal agent ofstem rust), and acceptable end-use quality. This paper will discuss ourstrategy for breeding cultivars with acceptable end-use quality. Allexperimental lines are derived from crosses with at least one or moreparents with acceptable end-use quality. As soon as individual lines areidentified (F₅) generation, microquality analyses are conducted andapproximately 10% are discarded on the basis of poor end-use quality. Inthe F₆ and later generations, samples are composited from three ormore locations/year, milled on a Buhler Mill, and baked using 100 g offlour per loaf. Though genotype-by-environmental interactions are large forend-use quality traits, composite samples are satisfactory for determiningthe end-use quality when repeated over time. By using phenotypicselection, the program has released cultivars with acceptable qualityinvolving known `poor' quality genes and chromosomes, such ashigh-molecular weight (HMW) glutenin subunits 2+12 (Scout 66 andLancota), 1BL.1RS (heterogeneous in Rawhide and homogeneous inCougar), and 1AL.1RS (heterogeneous in Nekota and Niobrara).Phenotypic selection is preferred to genotypic selection.     

对小麦不同HMW麦谷蛋白亚基质量评分系统的评价

小麦HMW麦谷蛋白亚基组成不同是造成各品种间烘烤品质差异的主要原因。不同研究者分别依据亚基间沉淀值（Payne等,1987）、评价值（傅宾孝等．1989）、抗延伸力（赵友梅等,1990）以及包括沉淀值在内的多个性状（赵和等,1994）的差异。先后建立了各自的评分系统。比较研究结果表明,前3种亚基评分系统对亚基的质量评分具有一定的共性,个别亚基的评分则存在差异;赵和等（1994）的评分系统则侧重考虑1D控制的亚基对烘烤品质的决定性作用,1A和1B控制的亚基作用甚小,因而与其余3种评分方法存在较大分歧。相关分析结果表明,就评价中国小麦品种的品质而言,国内制订的评分系统优于国外的。除容重、灰分等性状外,HMW麦谷蛋白亚基组成与大多数品质性状呈显著或极显著相关关系．     

鲜湿面条专用小麦品种品质的评价

32个小麦品种(农家种2个，育成种23个，国外品种7个)的面粉品质与鲜湿面条的煮熟品质的研究，结果表明：煮面感官评分≥80分的12个优质面条小麦以强筋品种为主，兼有个别中筋品种。沉淀值、稳定时间和最大抗延阻力是决定鲜湿面条品质的主要品质性状。蛋白质含量、面筋含量和面团延伸性应有一个适宜的范围，超过范围面条感官评