基因型、地点及其互作对内蒙古小麦主要品质性状的影响

选用来自我国春播麦区高、中、低3种筋力类型的9个品种, 于2003和2004年分别种植在内蒙古6个代表性地点, 研究了不同品种在年份和地点间籽粒硬度、蛋白质含量、和面仪参数和淀粉糊化特性等主要品质性状的变化规律。结果表明, 所测品质性状受基因型和地点效应的影响均达极显著水平, 除籽粒蛋白质含量外, 其他品质性状受基因型和地点互作效应的影响达显著或极显著水平。强筋类品种的蛋白质含量、灰分含量、沉降值、和面时间、耐揉性和峰值黏度均较高, 出粉率和稀澥值中等。中筋类品种出粉率、和面时间和耐揉性较高, 灰分含量、峰值黏度和稀澥值较低。弱筋类品种的灰分含量、峰值黏度和稀澥值较高, 籽粒硬度、蛋白质含量、出粉率、沉降值、和面时间、耐揉性低。所有品种品质性状在地点间存在较大差异, 乌海市灰分含量、和面时间和耐揉性高, 籽粒硬度、沉降值、峰值黏度和稀澥值较低。杭锦后旗出粉率高, 蛋白含量和沉降值较低, 其他性状表现中等。呼和浩特市籽粒硬度、蛋白含量、面粉灰分、沉降值、和面时间和耐揉性高, 出粉率、峰值黏度和稀澥值低。赤峰市多数性状表现中等。通辽市籽粒硬度、蛋白质含量、峰值黏度、稀澥值和耐揉性较高, 其他性状表现中等。额尔古纳市蛋白含量和沉降值较高, 和面时间和耐揉性低。初步认为强筋和中筋类品种较适于种植在呼和浩特市与乌海市, 不适于种植在额尔古纳市; 2个弱筋类品种在6个地点均不太适宜种植。     

Milling quality and protein properties of autumn-sown Chinese wheats evaluated through multi-location trials

Eight milling quality and protein properties of autumn-sown Chinese wheats were investigated using 59 cultivars and advanced lines grown in 14 locations in China from 1995 to 1998. Wide ranges of variability for all traits were observed across genotypes and locations. Genotype, location, year, and their interactions all significantly influenced most of the quality parameters. Kernel hardness, Zeleny sedimentation value, and mixograph development time were predominantly influenced by the effects of genotype. Genotype, location and genotype × location interaction were all important sources of variation for thousand kernel weight, test weight, protein content, and falling number, whereas genotype × location interaction had the largest effect on flour yield. Most of the genotypes were characterized by weak gluten strength with Zeleny sedimentation values less than 40 ml and mixograph development time shorter than 3 min. Eight groups of genotypes were recognized based on the average quality performance, grain hardness and gluten strength were the two parameters that determined the grouping, with contributions from protein content. Genotypes such as Zhongyou 16 and Annong 8903 displayed good milling quality, high grain hardness, protein content and strong gluten strength with high sedimentation value and long mixograph development time. Genotypes such as Lumai 15 and Yumai 18 were characterized by low grain hardness, protein content and weak gluten strength. Genotypes such as Yannong 15 and Chuanmai 24 were characterized by strong gluten strength with high sedimentation value and long mixograph development time, but low grain hardness and protein content lower than 12.3%. Genotypes such as Jingdong 6 and Xi’an 8 had weak gluten strength, but with high grain hardness and protein content higher than 12.2%. Five groups of locations were identified, and protein content and gluten strength were the two parameters that determined the grouping. Beijing, Shijiazhuang, Nanyang, Zhumadian and Nanjing produced wheats with medium to strong gluten strength and medium protein content, although there was still a large variation for most of the traits investigated between the locations. Wheat produced in Yantai was characterized by strong gluten strength, but with low protein content. Jinan, Anyang and Linfen locations produced wheats with medium to weak gluten strength and medium to high protein content. Wheats produced in Yangling, Zhenzhou, and Chengdu were characterized by weak gluten strength with medium to low protein content, whereas wheats produced in Xuzhou and Wuhan were characterized by weak gluten strength with low protein content. Industrial grain quality could be substantially improved through integrating knowledge of geographic genotype distribution with key location variables that affected end-use quality.     

稻田套播和氮素对中筋小麦产量和品质的调节效应

采用稻田套播与传统条播两种栽培方式系统比较的方法,研究不同氮肥运筹下稻田套播方式对中筋小麦扬麦10号籽粒产量和品质的调节效应。结果表明：稻田套播方式对中筋小麦籽粒产量和品质影响显著。与传统条播方式相比,在同一氮肥运筹下套播方式中筋小麦除籽粒总淀粉及其组分含量显著高于条播方式外,籽粒产量、蛋白质含量、蛋白质产量、磨粉品质和面粉品质以及淀粉糊化特性的主要指标低于传统条播,且差异显著。稻田套播方式不利于中筋小麦扬麦10号优质的形成,在江苏淮南地区中筋专用小麦采用稻田套播方式宜适当增加施氮量且追氮适度后移。     

SDS不溶性谷蛋白大聚体含量与和面仪参数的关系

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。     

QTL analysis of quality traits in the spring wheat cross RL4452 × 'AC Domain'

Wheat grain quality is a complex group of traits of tremendous importance to wheat producers, end‐users and breeders. Quantitative trait locus (QTL) analysis studied the genetics of milling, mixograph, farinograph, baking, starch and noodle colour traits in the spring wheat population RL4452/‘AC Domain’. Forty‐seven traits were measured on the population and 99 QTLs were detected over 18 chromosomes for 41 quality traits. Forty‐four of these QTLs mapped to three major QTL clusters on chromosomes 1B, 4D, and 7D. Fourteen QTLs mapped near Glu‐B1, 20 QTLs mapped near a major plant height QTL on chromosome 4D, and 10 QTLs mapped near a major time to maturity QTL on chromosome 7D. Large QTLs were detected for grain and flour protein content, farinograph absorption, mixograph parameters, and dietary fibre on chromosome 2BS. QTLs for yellow alkaline noodle colour parameter L* mapped to chromosomes 5B and 5D, while the largest QTL for the b* parameter mapped to 7AL.     

Wheat quality traits and quality parameters of cooked dry white Chinese noodles

Dry white Chinese noodle (DWCN) is widely consumed in China, and genetic improvement of DWCN quality has become a major objective for Chinese wheat breeding programs. One hundred and four bread wheat cultivars and advanced lines, including 88from major Chinese wheat-producing areas, were sown in two locations for two years. Their DWCN quality, as evaluated by trained panelists, was studied to determine the relationship between wheat quality parameters and DWCN quality attributes. In general, the cultivars and advanced lines used in this study are characterized with acceptable protein content, but accompanied with weak-medium gluten strength and poor extensibility, and substantial variation is observed for all grain and DWCN quality characters. On average, Australia and USA wheat performed better DWCN quality than Chinese wheats. Simple correlation analysis indicated that both grain hardness and Farinograph water absorption were negatively associated with cooked DWCN color, appearance, smoothness, and taste. Flour whiteness and RVA peak viscosity was positively associated with all DWCN parameters, and their correlation coefficients (r) with DWCN score are 0.34 and 0.41, respectively. Their positive contributions to DWCN quality were mostly through improved color, appearance, smoothness, and taste. Farinograph mixing tolerance index (MTI) and softening were negatively associated with all DWCN quality parameters, and their correlation coefficients with DWCN score are –0.50 and–0.54, respectively. Further analysis indicated that association between protein content, Zeleny sedimentation value, Farinograph stability, and Extensograph extensibility, and DWCN score fit quadratic regression model significantly, with R² 0.12, 0.32, 0.22, and 0.20, respectively. The associations between Zeleny sedimentation value and DWCN's appearance and taste also fit quadratic regression model significantly. This suggests that to certain extent, increased protein content and gluten quality contribute positively to DWCN quality, mostly by improving palatability, elasticity, and stickiness. High flour whiteness, medium protein content, medium to strong gluten strength and good extensibility, and high starch peak viscosity are desirable for DWCN quality. Genetic improvement for flour whiteness, protein quality and starch paste viscosity would increase the DWCN quality of Chinese bread wheat cultivars. This revised version was published online in July 2006 with corrections to the Cover Date.     

普通小麦面筋强度早代选择研究

以优质强筋小麦品种中优9507为母本,与安农91168、高优503、冀5099、晋麦45和鲁麦5号5个筋力不同的品种配制杂交组合,用亲本、F₁、F₂和F_2:3家系研究了SDS沉降值与和面时间的分布,分析了沉降值的遗传力和选择响应。结果表明,组合间F₂、F_2:3沉降值及F_{2:3相似文献}   

冬小麦高、低分子量麦谷蛋白亚基形成时间和积累强度及其与沉降值的关系

采用6个不同品质类型冬小麦品种研究高、低分子量麦谷蛋白亚基形成时间和积累强度及其与沉降值的关系。结果表明, 在籽粒形成过程中,各品种的高分子量谷蛋白亚基（HMW-GS）开始形成时间及形成速度不同,低分子量谷蛋白亚基（LMW-GS）B区在花后10 d基本形成;随着籽粒发育,HMW-GS和LMW-GS的类型和积累量都逐渐增多。强筋小麦     

江苏省优质软麦品种品质特性与饼干加工品质的关系

明确软麦品种在大田生产中的品质表现和品质育种筛选指标,对于优质生产及提高育种效率具有重要意义。选用江苏淮南麦区15份优质软麦品种(系),鉴定其高分子量麦谷蛋白亚基(HMW-GS)组成,开展3个试验点次的大田种植,分析了小麦样本的籽粒硬度、灰分含量、蛋白质含量和质量参数、粉质仪参数、揉面仪参数、溶剂保持力、贮藏蛋白组分含量参数、黏度仪参数等品质性状和饼干加工品质。结果表明,不同类型的品质参数受基因型和环境的影响不同。所有样本的蛋白质含量、湿面筋含量、稳定时间均不达国标(GB/T 17320-2013、GB/T 17893-1999),部分品种(系)的沉淀值达标,所有样本的籽粒硬度和吸水率全部达标。相关性分析表明,籽粒硬度、灰分含量和黏度仪参数与饼干加工品质无显著相关性。沉淀值、粉质仪吸水率、粉质仪稳定时间、揉面仪峰值时间、揉面仪衰落角、水溶剂保持力、碳酸钠溶剂保持力、乳酸溶剂保持力、谷蛋白/醇溶蛋白比、不溶性谷蛋白含量和不溶性谷蛋白百分含量与饼干直径呈显著(r≤–0.520)或极显著(r≤–0.652)负相关,相关系数分别为–0.657、–0.601、–0.617、–0.659、–0.676、–0.857、–0.726、–0.616、–0.546、–0.541和–0.637。多元回归方程显示,水溶剂保持力可解释饼干直径变异的73.76%,与籽粒蛋白共同可解释饼干直径变异的83.90%。在籽粒硬度和蛋白含量选择的基础上,降低面筋强度和面粉综合吸水特性是软麦育种的主要目标,水溶剂保持力、乳酸溶剂保持力和揉面仪参数是软麦育种最重要的筛选指标。     

强筋小麦磨粉各出粉点的面粉品质特性研究

采用布勒实验磨制粉,测定6个强筋小麦品种不同出粉点面粉的品质特性。结果表明,不同出粉点面粉的品质特性具有明显差异及变化规律。三道心磨粉的灰分含量、蛋白质含量、面糊色泽a*值和b*值、破损淀粉含量、面团形成时间和吸水率随出粉点后移均呈升高或增加趋势;而湿面筋含量、面糊色泽L*值、面团稳定时间、延伸性和最大抗延阻力随出粉点后移而降低。三道皮磨粉的蛋白质含量、湿面筋含量、破损淀粉含量、面团吸水率、稳定时间、拉伸面积、延伸性随出粉点后移呈上升趋势;而面团拉伸参数和面包烘焙品质均高于心磨粉和统粉。不同出粉点的蛋白质与湿面筋含量呈极显著正相关(r=0.81**);灰分含量与面糊色泽的L*值呈极显著负相关(r=－0.89**);破损淀粉含量与吸水率呈极显著正相关(r=0.86**)。研究表明,通过对各出粉点取舍及混配,能够克服我国强筋小麦某些指标缺陷,以满足面包专用粉各项指标要求。     

Effects of the 6VS.6AL translocation on agronomic traits and dough properties of wheat

Nineteen common wheat cultivars and advanced lines carrying a 6VS.6AL translocation and five parents were sown at two locations in Jiangsu in 2004–05 season to assess the effects of the translocation on grain yield and dough properties. In general, there were no significant differences between 6VS.6AL lines and their recurrent parents in agronomic, mixograph and starch pasting traits, including grain yield, grains/spike, grain weight/spike, mixing time and peak viscosity. 6VS.6AL lines showed slightly but significantly higher thousand-kernel weight and plant height, and small negative effects on test weight, flour yield and flour colour. However, significant variation occurred for all traits among sister lines from the same cross, indicating that additional selection could lead to further improvement. It was concluded that the 6VS.6AL translocation can be used in wheat breeding programs as a donor of resistance to powdery mildew with no obvious undesirable effects on agronomic and quality traits.     

四川小麦主栽品种的品质性状表现及其稳定性

2006—2008连续3年,在5个生态点考察了7个四川省代表性小麦品种在两种氮水平下的品质状况及其稳定性,以期为四川小麦品质定位、品质改良和生产指导提供依据。结果表明,3年均值,籽粒容重777 g L^-1,籽粒蛋白质含量12.3%,湿面筋含量25.1%,Zeleny沉降值32.9 mL,降落值326 s,面粉吸水率56.5%,面团形成时间3.0 min、稳定时间4.5 min,面条评分78.5分、面包评分62.2分。几乎所有品质性状均存在显著的基因型、环境及其互作效应。籽粒容重、沉降值、降落值、面粉吸水率和面条评分的年份效应大于地点效应,而籽粒蛋白质含量、湿面筋含量、面团形成时间、稳定时间和面包评分则地点效应大于年份效应。增施氮肥对籽粒蛋白质含量、湿面筋含量、沉降值、面团形成时间、稳定时间和面包评分都有显著的增效作用,但对降落值、面粉吸水率和面条评分无明显影响。品种品质的稳定性因品质性状不同而异,川麦39面包评分高而稳定,川麦37面条总评分高而稳定,二者可被用于四川小麦品质改良。     

Expression of seed storage proteins responsible for maintaining kernel traits and wheat flour quality in common wheat under heat stress conditions

Heat stress during grain filling has been documented to decrease wheat grain yield and quality in arid regions worldwide. We studied the effect of heat stress on wheat flour quality in heat tolerant cultivars to define the effects of heat stress on flour quality and to identify germplasm combining traits for heat tolerance and good flour quality. We studied the kernel phenotypic traits, the expression of seed storage proteins (SSPs), and the resulting flour quality under heat and normal conditions. Under heat stress, all cultivars yielded narrow-shaped seeds, and increased protein contents as compared to the control plants grown under normal conditions. The specific sedimentation values used to estimate the gluten quality varied between cultivars. We identified cultivars that could maintain good flour quality under heat stress conditions: ‘Imam’, which possessed the Glu-D1d allele responsible for the suitable bread-making; ‘Bohaine’, which displayed high expression level of SSPs; and ‘Condor’, which possessed slight variations in the ratio of each SSP under heat stress conditions. Combining the desirable traits from these cultivars could yield a wheat cultivar with heat tolerance and good flour quality.     

Suitability of Chinese wheat cultivars for production of northern style Chinese steamed bread

Fifty-six bread wheat cultivars and advanced lines from major Chinese wheat growing regions and 10 Australian cultivars were grown in Anyang located in Yellow and Huai Valleys and Chengdu located in Yangtze region. The genotypes were examined for their suitability to produce northern style Chinese steamed bread (CSB) and used to investigate the association between wheat quality traits and performance of northern style CSB under manual and mechanized processing conditions. Anyang-sown wheat samples showed better grain quality characteristics and CSB quality than the Chengdu-sown materials. These differences were largely due to adverse climatic conditions prevailing in Chengdu that resulted in the deterioration of flour whiteness, Farinograph stability, and starch quality. Therefore, Chengdu was generally unfavorable for producing good quality wheat. However, significant variability among cultivars was observed in Chengdu, and Batavia, Dollar bird, and Tasman from Australia and Jing 411, Xiaoyan6, and Shaan 229 from China showed very good CSB quality under manual conditions, and Hartog, Batavia, Tasman, and Vulcan from Australia, and Jing 411 and Dongfeng 1from China were identified to confer good CSB quality under mechanized conditions. The wide range of CSB quality variations indicates that genetic improvement of CSB quality is possible in both environments. Protein content, gluten strength, and extensibility were positively associated with loaf volume and steamed bread elasticity. The relationship between gluten strength, extensibility, and appearance and stickiness were highly dependent on processing methods, i.e., negatively using a manual method and positively or slightly negatively using a mechanized process. Therefore, wheat quality requirement for CSB depends on CSB processing conditions. Medium protein content and medium-to-strong gluten strength with good extensibility is desirable for mechanized methods, but weak-to-medium gluten type for manual methods. High flour whiteness and RVA peak viscosity was found desirable for CSB quality regardless of the processing method used. Flour whiteness, falling number, and peak viscosity appeared to be more crucial in determining CSB quality in Chengdu, although protein content and Farinograph stability also contributed to appearance, elasticity, and stickiness. This revised version was published online in July 2006 with corrections to the Cover Date.     

Quality of Ethiopian Durum Wheat Lines in Two Diverse Environments

In Ethiopia, durum wheat is largely used for production of local fermented and flat bread. Two diverse environments (Motta and Adet) were used to evaluate 15 durum wheat genotypes for grain yield and quality traits. The mean flour protein content of genotypes ranged from 10.1 % to 12.5 % and 6.7 % to 8.1 % at Motta and Adet respectively. The mean mixograph development time was 4 min at Motta and 2.8 min at Adet and SDS (Sodium dodecyl sulphate) sedimentation ranged between 10.7 and 32.3 ml across locations. Flour protein content was correlated negatively with mixograph development time and positively with vitreous kernels and single‐kernel hardness at both environments. Mixograph development time was selected to predict the gluten strength. Flour protein content, SDS sedimentation and seed weight were included in a stepwise regression. A prediction model was compiled that explained 69 % of the variation for mixograph development time.     

高产小麦品种‘济麦22’配粉效应及馒头制作品质研究

为了深入了解‘济麦22’的食品加工特性和配粉技术,更大程度地发挥‘济麦22’的高产潜力价值及为面粉企业更好地利用该品种提供理论依据。将当前大面积推广的小麦品种‘济麦22’面粉按0、20%、40%、60%、80%和100%比例分别与‘济南17’和‘济宁13’面粉混合,形成不同类型的配粉,研究了配粉的面粉颜色、蛋白质特性、面团揉混特性、淀粉RVA糊化特性等变化及馒头品质表现。结果表明,不同类型配粉的品质特性存在差异,‘济麦22’与‘济南17’的2、3号配粉的白度、面片色泽、蛋白质特性和面团揉混特性等均有较好改善,3、4号配粉具有较好的RVA糊化特性,3、4号配粉的馒头品质较好;‘济麦22’与‘济宁13’的4、5号配粉的面粉白度和面片色泽特性较好,3号配粉具有较好的蛋白特性,3、4、5号配粉的面团揉混特性和RVA糊化特性得到一定改善,2、3号配粉的馒头品质较好。这说明添加一定比例的‘济麦22’面粉到‘济南17’或‘济宁13’面粉中可以生产出适合制作优良馒头的面粉。‘济麦22’与‘济南17’面粉的合理搭配不仅可以合理利用有限的‘济南17’优质小麦,更重要的是使‘济麦22’的高产潜力得到更好地发挥,在最大程度上提高‘济麦22’和‘济南17’原粮的经济价值和使用价值。     

Genotypic and temperature effects on wheat grain yield and quality in a hot irrigated environment

High temperature influences both grain yield and end‐use quality of wheat. The objectives of this study were to evaluate the performance of selected wheat genotypes under heat stress and to examine the effects of high temperatures during grain filling on grain yield and end‐use quality parameters. Fifteen bread wheat genotypes in 2000/2001 and 18 genotypes in 2002/2003 were evaluated under the optimum and late‐sowing conditions of the irrigated hot environment of the Gezira Research Farm, Wad Medani, Sudan. The genotypes comprised released varieties and elite lines from the Sudanese wheat improvement programme. Data collected included grain yield, grain weight and grain end‐use quality including protein content, protein composition, SDS sedimentation values (SDSS) and gluten strength as determined by mixograph analyses. High temperatures significantly decreased grain yield by decreasing grain weight. Although genotypes exhibited variation in magnitude of response, results indicated that high temperature during grain filling increased both soluble and insoluble protein contents, SDSS, mixograph peak height (MPH) and the descending slope at 2 min past peak (MDS). In contrast, mixograph peak time (MPT) and the curve width at 2 min past peak (MCW) were significantly decreased. Flour protein correlated positively with SDSS, MPH and MDS and negatively with MCW. MPT correlated negatively with MDS and positively with MCW. Results indicate that high temperature increased both soluble and insoluble protein contents, SDSS and MPH, and hence the gluten strength, but decreased flour mixing time and tolerance and hence the dough elasticity. Variation observed among genotypes suggests that grain end‐use quality could be improved under high temperature conditions utilizing the available variability; however, it might require evaluation under various growing conditions.     

Mixolab参数与粉质、拉伸参数及面包烘烤品质的关系

根据仪器测定的面粉品质特性预测面包烘烤品质是进行小麦品质改良的重要方法。法国肖邦公司(Chopin Technologies, France)最新推出的Mixolab分析仪可以同时测定面粉加水后恒温揉混及面团升温后蛋白质弱化和淀粉糊化特性,明确其与现有相似仪器如粉质仪和拉伸仪等的关系对小麦品质测试具有重要意义。利用 Mixolab分析仪、粉质仪、拉伸仪测定了41份高代育种品系的有关参数和面包烘烤品质,并分析了Mixolab与粉质仪和拉伸仪相关参数的关系及预测面包品质的可靠性。结果表明,可以用Mixolab的形成时间、稳定时间、面团受热后蛋白质弱化值(C2值)和到达淀粉糊化反弹值的时间(C4时间)来预测粉质仪和拉伸仪的品质参数,可解释其变异的74%~90%;可以直接用C2值预测面包体积、外观、结构和总分,决定系数分别为52%、73%、70%和68%;预测面包质地和弹性的参数不仅包含Mixolab稳定时间和C2值,还有表示淀粉糊化特性的C3时间、C4和C5值及C5温度。用Mixolab分析仪既可以了解蛋白质特性和面包烘烤品质的关系,又明确了淀粉品质对面包品质的显著影响,在品质测试中有其独特之处。Mixolab、粉质仪和拉伸仪各参数对预测小麦面包体积、内部质地结构等烘烤品质性状的贡献不同。     

Breeding durum wheat for pasta quality in Canada

Canada was the largest durum wheat (Triticum turgidum var durum) producer in 1994, and in recent years supplied over 70% of world export trade in durum. Breeding for pasta quality is, therefore, a primary objective in Canadian durum breeding programs. Control of cultivar registration and stringent grading standards ensure that durum of consistent high quality is produced for domestic and export markets. The objectives of breeding programs include: improvement of traits related to production concerns, such as grain yield, disease resistance and sprouting resistance, and those related to end-use quality, such as protein concentration and quality; milling quality factors, such as semolina yield; colour of the wheat, semolina and pasta; and cooking quality. Selection and testing for quality begins at very early generations and becomes more stringent for advanced inbred lines. Selection is practised at the F₁ or F₂, where appropriate, using monoclonal antibodies to identify desirable gamma gliadins (γ-45 ) or low molecular weight glutenin subunits (LMW 2) that have been shown to be related to end-use quality. Grain from early generation yield trials, starting at F₄, is screened for protein concentration and pigment content by Near Infrared reflectance, and for gluten strength by sodium dodecyl sulphate (SDS) sedimentation and micro-mixograph. Promising lines entered into multi-location yield trials are screened with more time-consuming procedures to fully assess suitability for pasta processing. These tests include semolina yield, ash and colour, and predictions of gluten strength such as mixograph and alveograph, and cooking quality. Candidate cultivars with quality equal to or better than the mean of the check cultivars can be proposed for registration after three years in the Durum Cooperative Test. It takes approximately 10 years from performing a cross to registrating a new cultivar. This revised version was published online in August 2006 with corrections to the Cover Date.     

Genetic improvement trends in agronomic performances and end-use quality characteristics among hard red winter wheat cultivars in Nebraska

Evaluation of wheat cultivars from different eras allows breeders to determine changes in agronomic and end-use quality characteristics associated with grain yield and end-use quality improvement over time. The objective of this research was to examine the trends in agronomic and end-use quality characteristics of hard red winter wheat cultivars grown in Nebraska. Thirty historically important and popular hard red winter wheat cultivars introduced or released between 1874 and 2000 were evaluated at Lincoln, Mead and North Platte, Nebraska in 2002 and 2003. An alpha lattice design with 15 incomplete blocks of two plots and three replications was used at all locations. Agronomic (days to flowering, plant height, spike length, culm length, grain yield and yield components, and grain volume weight) and end-use quality (flour yield, SDS-sedimentation value, flour protein content, and mixograph time and tolerance) traits were measured in each environment. Highly significant differences were observed among environments, genotypes and their interactions for most agronomic and end-use quality characteristics. Unlike modern cultivars, older cultivars were low yielding, and less responsive to favorable environments for grain yield and yield components. Semidwarf cultivars were more stable for plant height than traditional medium to tall cultivars. All cultivars had high grain volume weight since it is part of the grading system and highly selected for in cultivar release. Modern cultivars were less stable than older cultivars for SDS-sedimentation and mixing tolerance. However, the stability of older cultivars was attributed to their having weak mixing tolerance and reduced SDS-sedimentation values. The reduced protein content of modern cultivars was offset by increased functionality, as measured by mixograph and SDS sedimentation. In conclusion, breeders have tailored agronomic and end-use quality traits essential for hard red winter wheat production and marketing in Nebraska.