Zinc nutrition influences the protein composition of flour in bread wheat (Triticum aestivum L.)

Zinc (Zn) deficiency and heat stress during grain filling occur in a number of important wheat growing regions around the world. The changes in grain protein composition due to high temperature are well documented, but little is known about the effect of grain Zn and its interaction with heat stress. Six field experiments were conducted at sites differing in grain filling temperatures to examine these effects. Two varieties of bread wheat were grown at six rates of Zn, including foliar sprays of Zn. The relative amounts of gliadin and polymeric protein were measured by size exclusion HPLC. Applying Zn increased grain yield at three sites and altered protein quality at two of these. Foliar Zn applications doubled grain Zn concentration, reduced the proportion of gliadin and SDS-unextractable polymeric protein and increased the proportion of SDS-extractable polymeric protein. Heat stress during grain filling was associated with a high proportion of gliadin and low proportions of the polymeric protein in the grain. However, the proportions of gliadin and of SDS-extractable polymeric protein were less affected by high temperatures in grain with high Zn concentrations. The results demonstrate that Zn nutrition can alter protein composition and the effects of Zn may interact with grain filling temperatures.     

碳氮供给对小麦离体穗培养粒重、微量元素及蛋白质含量的影响

为了解碳氮供给与小麦粒重、Fe、Zn、Mn、Cu等微量元素以及蛋白质含量的关系,在离体穗培养条件下研究了灌浆初期和灌浆中期不同浓度C(蔗糖)、N(硝酸铵)供给对小麦粒重、微量元素(Fe、Zn、Mn、Cu)和蛋白质含量的影响.结果表明,随着培养基糖浓度的增大,粒重和Fe、Mn含量都表现为先升高后降低的趋势,在4%糖浓度时,均达到最高值;籽粒Zn、Cu和蛋白质含量表现为随糖浓度增大而持续降低.随着培养基N浓度的增加,粒重和Fe、Zn、Mn、Cu含量多表现为先升高后降低的趋势,且多在N浓度为0.07%时达到最高值,尤以灌浆中期开始的培养表现明显;籽粒蛋白质含量表现为随N浓度增大而持续增加.由此可见,外源C、N供给对粒重、微量元素和蛋白质含量有明显的调控效应.一定的糖供给可同时提高粒重和Fe、Mn含量,一定的N供给可同时提高粒重及微量元素和蛋白质含量.     

Variation in mineral micronutrient concentrations in grain of wheat lines of diverse origin

150 lines of bread wheat representing diverse origin and 25 lines of durum, spelt, einkorn and emmer wheat species were analysed for variation in micronutrient concentrations in grain. A subset of 26 bread wheat lines was grown at six sites or seasons to identify genetically determined differences in micronutrient concentrations. Substantial variation among the 175 lines existed in grain Fe, Zn and Se concentrations. Spelt, einkorn and emmer wheats appeared to contain higher Se concentration in grain than bread and durum wheats. Significant differences between bread wheat genotypes were found for grain Fe and Zn, but not Se concentration; the latter was influenced more by the soil supply. Grain Zn, but not Fe, concentration correlated negatively with grain yield, and there was a significant decreasing trend in grain Zn concentration with the date of variety release, suggesting that genetic improvement in yield has resulted in a dilution of Zn concentration in grain. Both grain Zn and Fe concentrations also correlated positively and significantly with grain protein content and P concentration, but the correlations with kernel size, kernel weight or bran yield were weak. The results from this study are useful for developing micronutrient biofortification strategies.     

北京地区不同年代冬小麦品种籽粒微量元素含量的变化及其对水分的响应

为探讨北京地区小麦品种更替过程中籽粒微量元素含量的演变规律,选用20世纪60年代以来小麦品种更替过程中的7个主要推广品种,分别种植在春不浇水和春浇二水条件下,测定了小麦籽粒中Fe、Zn、Mn、Cu、蛋白质含量以及籽粒产量.结果表明,北京地区小麦品种更替过程中,随着产量的提高,籽粒微量元素含量并没有出现明显的稀释效应,而且有些营养成分含量(如Fe、Mn)随着年代更替出现明显提高的趋势;春不浇水降低了籽粒Fe、Zn、Cu和蛋白质含量,但提高了籽粒Mn含量.相关分析表明,小麦籽粒Fe、Zn、Cu含量与蛋白质含量呈正相关,Fe、Zn、Mn、Cu、蛋白质含量与籽粒产量、穗粒数和千粒重以及年代之间也呈正相关,说明在产量改良的过程中有望同步提高籽粒微量元素和蛋白质含量.     

Mineral and protein content,test weight,and yield variations of hard red spring wheat grain as influenced by fertilization and cultivar

Among the complex factors affecting grain nutritional quality, protein and mineral content are highly important. A two-year study was conducted in eastern North Dakota to determine the influence of fertility on the protein and mineral content, test weight, and yield of two hard red spring wheat (Triticum aestivum L.) cultivars. Zero, medium (56, 12, and 47 kg/ha), and high (280, 122, and 465 kg/ha) rates of N, P, and K, respectively, were applied in a complete factorial arrangement to ‘Era’ (a semi-dwarf) and ‘Waldron’ wheat (a tall type) in 1977. Seven of these treatments were repeated in 1978. Micronutrients and S were also applied to most treatments in 1977, and micronutrients but no S to all treatments in 1978. In 1977 on a site with high residual NO₃-N, additions of N reduced yields and test weight but increased protein, P, Ca, Zn, Mn, and Fe content. At this site application of P increased grain yield, P, K, and Mg contents but reduced protein and Zn; fertilizer K increased Mn and Fe content and reduced yield, P, K, and Mg. In 1978, N additions increased grain yield, protein, Ca, and Fe but reduced Zn. The application of P and K had little influence on the composition of the grain in 1978. The two cultivars acted the same both years, with Waldron exceeding Era grain in protein (15%), P (12%), Mg (12%), Mg (12%), Zn (17%), Mn (30%), and Fe (12%). Era surpassed Waldron in test weight (2%), K (2%), and Ca (27%). Era proved to be more responsive to fertilizer additions for most grain parameters. Drier weather conditions and lower soil N status for the 1978 experiment produced grain higher in test weight and P, K, Ca, Mg, and Fe content but lower in yield, protein, and Zn. Many highly significant fertilizer-grain and grain-grain interactions were observed. Since wheat grain composition may often be altered by fertilizers and cultivars, the range of these changes should become known through investigations by soil scientists, agronomists, and nutritionists; additional research should be conducted to determine if their changes are of nutritional significance.     

新疆春小麦育成品种耐热性评价

为筛选出耐热性好的小麦种质材料，通过开花期至成熟期人工模拟高温胁迫环境，以千粒重热感指数为主要评价指标，评价了新疆近30年来审定的春小麦品种的相对耐热性，并分析了高温胁迫对小麦籽粒蛋白质、湿面筋含量的影响。结果表明，与自然生长相比，高温胁迫条件下新疆春小麦育成品种的千粒重、籽粒宽度的变化均达到了极显著水平（P<0.01），籽粒长度变化不显著(P>0.05)，不同品种间耐热性存在很大差异。综合三年千粒重热感指数（HSI）分析，耐热性相对较好的品种有17个，连续三年HSI＜1的品种有11个，其中新春37号、新春2号、新春38号在高温胁迫条下千粒重变化较小，产量较稳定，为强耐热品种；对高温敏感品种有26个，连续三年HSI≥1的品种有13个，其中新春13号、新春18号、新春33号耐热性相对较弱。高温胁迫影响小麦籽粒的品质，其中13.95%的品种蛋白质含量降低，6.98%的品种湿面筋含量降低，其他品种高温胁迫后籽粒蛋白质、湿面筋含量均较自然生长有所提高。     

灌浆期涝渍害对弱筋小麦籽粒产量及品质的影响

长江中下游是我国主要的弱筋小麦产区,该区小麦生育后期涝渍害频发,严重影响小麦的高产和稳产。为探明涝渍害对弱筋小麦产量及品质的影响,以优质弱筋小麦品种扬麦13、扬麦15、扬麦22为材料,采用人工模拟涝渍害的田间试验方法,研究了灌浆期涝渍害对弱筋小麦籽粒产量及其构成要素、蛋白质含量、湿面筋含量、SDS沉淀值、吹泡仪参数、溶剂保持力SRC和粉质仪参数等主要品质指标的影响。结果表明:(1)灌浆期涝渍害导致小麦产量显著下降,有效穗数和穗粒数降低是引起扬麦13减产的主要因子,扬麦15和扬麦22的有效穗数、穗粒数和千粒重均降低导致减产。(2)涝渍害处理的扬麦13和扬麦22的湿面筋含量较对照显著上升,蛋白质含量和SDS沉淀值在处理间无显著差异。涝渍害处理7 d对供试小麦吹泡仪参数影响较大,扬麦13和扬麦15的L值和W值在涝渍害处理7 d后均显著提升,扬麦13的水SRC较对照显著下降。涝渍害处理7 d对供试小麦的粉质仪参数无显著影响。(3)供试的3个弱筋小麦品种籽粒品质受基因型的影响大于涝渍害。     

氮肥对不同玉米品种子粒微量元素含量和生物有效性的影响

研究田间施用氮肥对吉林省4个玉米品种子粒中Zn、Fe、Mn、Cu含量以及Zn与Fe生物有效性的影响。结果表明,施用氮肥可增加玉米子粒中Zn、Fe含量,过量施氮玉米子粒中Zn和Fe含量不再增加甚至呈下降趋势;子粒中Mn含量随氮肥增加而提高,Cu含量随氮肥增加而降低,4个品种中只有吉四单19在过量施氮时子粒Mn含量呈下降趋势。随氮肥水平提高,玉米子粒中Zn、Fe和Mn累积量呈递增趋势,Cu累积量变化不显著。全磷与这些矿物质元素的比值(P/Zn、P/Fe)表明,氮肥施用将显著降低玉米子粒中Zn和Fe的生物有效性。     

Identification of CIMMYT spring bread wheat germplasm maintaining superior grain yield and quality under heat-stress

Unpredictable temperatures and rainfall associated with climate change are expected to affect wheat (Triticum aestivum L.) production in various countries. The development of climate-resilient spring wheat cultivars able to maintain grain yield and quality is essential to food security and economic returns. We tested 54 CIMMYT spring bread wheat genotypes, developed and/or released over a span of 50 years, in the field for two years under optimum sowing dates, as well as using two delayed sowing dates to expose crops to medium and severe heat-stress conditions. The grain yield and yield components were severely affected as the heat-stress increased. Two contrasting groups of 10 lines each were identified to determine the effect of heat-stress on bread-making quality. The first set included entries that produced high yields in optimal conditions and maintained higher yields under heat-stress (superior-yielding lines), while the second set included genotypes that did not perform well in the environment with high temperature (inferior-yielding lines). We identified genotypes exhibiting bread-making quality stability, as well as the quality traits that had higher correlation with the loaf volume in the environment without stress and under heat-stress. Of all the quality traits tested, dough extensibility (AlvL) and grain protein content had a significant influence in heat-stress adaptation. Most of the lines from the superior-yielding group were also able to maintain and even improve quality characteristics under heat-stress and therefore, could be used as parents in breeding to develop high-yielding and stable quality wheat varieties.     

叶面喷施微肥对冬小麦产量和品质的影响

为给小麦高产优质栽培中微肥施用提供参考,以冬小麦品种石新828为材料,研究了叶面喷施锌、铁、硒3种微肥对小麦产量、籽粒锌、铁、硒和蛋白质含量的影响。结果表明,3种微肥中只有喷硒增产作用显著(P<0.05),但喷锌、铁、硒分别显著增加了千粒重、穗数和穗粒数。3种微肥均能明显提高籽粒中相应的微量元素含量,但对籽粒蛋白质含量影响均不显著。     

Heat and drought stress on durum wheat: Responses of genotypes,yield, and quality parameters

Heat and/or drought stress during cultivation are likely to affect the processing quality of durum wheat (Triticum turgidum L. ssp. durum). This work examined the effects of drought and heat stress conditions on grain yield and quality parameters of nine durum wheat varieties, grown during two years (2008–09 and 2009–10). Generally, G and E showed main effects on all the parameters whereas the effects of G × E were relatively small. More precipitation in Y09–10 may account for the large differences in parameters observed between crop cycles (Y08–09 and Y09–10). Combined results of the two crop cycles showed that flour protein content (FP) and SDS sedimentation volume (SDSS) increased under both stress conditions, but not significantly. In contrast the gluten strength-related parameters lactic acid retention capacity (LARC) and mixograph peak time (MPT) increased and decreased significantly under drought and heat stress, respectively. Drought and heat stress drastically reduced grain yield (Y) but significantly enhanced flour yellowness (FY). LARC and the swelling index of glutenin (SIG) could be alternative tests to screen for gluten strength. Genotypes and qualtiy parameters performed differently to drought and heat stress, which justifies screening durum wheat for both yield and quality traits under these two abiotic stress conditions.     

不同落黄型小麦品种光合器官衰老及产量对花后高温的响应

为给耐热性小麦品种的选育和推广提供依据,以黄淮北片小麦全身落黄型品种邯6172和邯麦13及灰白落黄型品种石4185和早衰落黄型品种鲁麦14为供试材料,研究了灌浆期热胁迫对小麦植株含水量、干物质转运量和籽粒灌浆特性的影响,并通过千粒重热感指数评价了不同类型品种的耐热性。结果表明,高温加快了小麦叶片黄化衰老,不同品种衰老快慢不同,邯6172和邯麦13的旗叶、倒2叶、倒3叶分别于热胁迫后19、16、10d开始黄化,叶片黄化速度慢,分别比鲁麦14、石4185晚3~6d。热胁迫使穗、茎、叶含水量下降,不同品种下降速率不同,灌浆后期差异更为显著,其中花后31d鲁麦14、石4185、邯6172和邯麦13穗部含水量分别比对照下降28.7%、30.3%、12.1%和17.4%,叶片含水量分别下降53.8%、44.4%、18.7%和21.5%;鲁麦14、石4185茎秆含水量始终低于邯6172和邯麦13,失水失绿早。热胁迫下全身落黄小麦叶片衰老速度慢,绿叶数目、绿叶面积均较高,穗茎叶含水量相对较高,充分延缓了叶片等光合器官的衰老,保证了正常的生理代谢功能,营养器官干物质转运量和籽粒灌浆速率下降幅度较小,千粒重降低不明显,产量和千粒重热感指数小于1,耐热性好。     

Breeding for increased grain protein and micronutrient content in wheat: Ten years of the GPC-B1 gene

To provide food and nutrition security for a growing world population, continued improvements in the yield and nutritional quality of agricultural crops will be required. Wheat is an important source of calories, protein and micronutrients and is thus a priority to breed for improvements in these traits. The GRAIN PROTEIN CONTENT-B1 (GPC-B1) gene is a positive regulator of nutrient translocation which increases protein, iron and zinc concentration in the wheat grain. In the ten years since it was cloned, the impacts of GPC-B1 allelic variation on quality and yield traits have been extensively analyzed in diverse genetic backgrounds in field studies spanning forty environments and seven countries. In this review, we compile data from twenty-five studies to summarize the impact of GPC-B1 allelic variation on fifty different traits. Taken together, the results demonstrate that the functional copy of the GPC-B1 gene is associated with consistent positive effects on grain protein, Fe and Zn content with only marginally negative impacts on yield. We conclude that the GPC-B1 gene has the potential to increase nutritional and end use quality in a wide range of modern cultivars and environments and discuss the possibilities for its application in wheat breeding.     

减少灌水次数对强筋小麦氮素积累转运和籽粒蛋白质含量的影响

为探究减少灌水次数对强筋小麦氮素积累、转运和籽粒蛋白质含量的影响,选用4个强筋小麦品种(津农7号、农优3号、师栾02-1和中麦998),在大田条件下设置3种灌水处理(CK:冬水+拔节水+开花水;W2:冬水+拔节水;W1:冬水),研究了减少灌水次数对强筋小麦植株各器官氮素的积累与转运、籽粒蛋白质及其组分的含量、蛋白质产量和籽粒产量的影响,并对协调强筋小麦籽粒蛋白质含量和产量的适宜灌水次数进行了探讨。结果表明,减少灌水次数后,强筋小麦营养器官氮素积累量明显降低,氮素转运量增加;籽粒蛋白质含量升高;蛋白质组分的变化表现为,清蛋白、球蛋白和谷蛋白含量升高,醇溶蛋白含量下降;籽粒产量显著下降,水分利用效率升高,但不同品种增幅不同。综上所述,减少灌水次数能促进强筋小麦营养器官的氮素向籽粒转运,使籽粒蛋白质含量升高,籽粒蛋白质品质得到改善。本试验条件下,W2处理(冬水+拔节水)可以有效协调强筋小麦产量和籽粒蛋白质含量的关系,同时提高水分利用效率。     

Determining the spirit yield of wheat varieties and variety mixtures

Four winter wheat varieties and the four possible three-component mixtures derived from them were included in a trial in Scotland. The site produced low grain protein levels and there were significant yield and specific weight differences between varieties. The variety Deben significantly out-yielded the varieties Claire and Riband, both with and without fungicide treatment, but produced grain with significantly lower spirit yield than Claire. Protein contents and thousand corn weights were good predictors of spirit yield in a reference population of wheat samples, but thousand corn weights did not correlate with spirit yield in the trial, as Claire combined small grain with high spirit yield. The relationship between protein and spirit yield was shown to change at lower protein levels and to differ between varieties. Reduction in spirit yield as protein increased was greater in Deben than in a better distilling variety like Consort. A rapid means of predicting spirit yield, based on small-scale measurement of hot water extract and protein content, was devised and a good association between predicted and measured spirit yield was observed in both the reference population and the trial. Mixtures containing cvs. Claire and Deben did not demonstrate the adverse effects on yield and spirit yield observed, respectively, for these varieties, and a mixture comprising cvs. Claire, Consort and Deben significantly out-yielded Claire and gave higher spirit yields than Deben. These benefits, together with the potential yield stability and disease reduction characteristics of wheat mixtures, make them a viable commercial option for distilling.     

不同氮反应冬小麦品种幼苗素质及氮代谢关键酶活性的耐低氮差异研究

为了明确不同氮敏感型冬小麦品种的幼苗对低氮胁迫的反应,基于小麦籽粒产量和籽粒氮含量的耐低氮指数,对24个冬小麦品种进行了耐低氮丰产型和氮敏感型分类,并以典型品种为材料,比较了其幼苗(5叶龄)在不施氮(0mmol·L~(-1))和施氮(16 mmol·L~(-1))条件下,地上部和根部的干物质积累量、氮含量、氮积累量及其叶片和根部的硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性。结果显示,与施氮处理相比较,不施氮处理小麦品种的幼苗根部干物质积累量、根冠比均增加,地上部干物质积累量、氮含量和氮积累量、根部氮含量和氮积累量以及NR和GS活性均降低。在不施氮处理下,耐低氮丰产型小麦品种的幼苗地上部干物质积累量的降幅小于氮敏感型品种,根部干物质积累量和根冠比的增幅均大于氮敏感型品种;耐低氮丰产型小麦品种幼苗总根长和总根表面积显著增加,根直径显著下降;氮敏感型小麦品种幼苗根直径和总根体积显著降低。与氮敏感型品种相比,耐低氮丰产型小麦品种幼苗地上部、根部的氮吸收能力较高,NR和GS两种酶活性降幅较小。     

施氮对花后遮光条件下小麦产量与蛋白质含量的影响

为探讨施氮对花后弱光逆境下小麦籽粒产量和蛋白质含量的影响,选用2个对弱光敏感性不同的小麦品种（济麦22和济核916）,设置3个施氮水平（0、120和240 kg·hm^-2）,在花后遮去60%的自然光条件下研究了施氮量对小麦籽粒产量与蛋白质含量的调控效应。结果表明,增施氮肥可延缓花后遮光条件下两个小麦品种旗叶叶绿素下降,使PSⅡ实际光化学效率和净光合速率维持较高水平,促进旗叶可溶性糖含量合成,提高籽粒灌浆速率,增加穗数、穗粒数和籽粒产量。增施氮肥提高了遮光条件下两个小麦品种旗叶硝酸还原酶活性、籽粒谷氨酰胺合成酶活性和籽粒游离氨基酸含量,增加籽粒蛋白质含量。济麦22的籽粒产量以240 kg·hm^-2施氮处理最高,籽粒蛋白质含量在120 kg·hm^-2和240 kg·hm^-2施氮处理间无显著差异;济核916的籽粒产量和蛋白质含量均以120 kg·hm^-2施氮处理最高。由此可见,在花后遮光条件下适量施氮可提高小麦光合能力和促进碳氮代谢,最终增加籽粒产量和蛋白质含量。     

叶面喷施富硒植物营养素对小麦产量及品质的效应

为了解外源硒对小麦产量及品质的影响,在不同小麦品种开花期叶面喷施富硒植物营养素,研究其对小麦籽粒产量、籽粒硒含量及品质指标的影响.结果表明,不同小麦品种开花期叶面喷施富硒植物营养素后,籽粒产量均增加,中麦895、登峰168和小偃22的产量依次较对照增加了5.9％、2.9％、4.6％;小麦籽粒有机硒和总硒含量均极显著增高,中麦895、登峰168和小偃22的有机硒含量较对照依次提高了537.3％、622.6％、5323.2％;总硒含量较对照依次增加了524.4％、757.8％、5 306.4％.开花期叶面喷富硒植物营养素对小麦籽粒的容重、蛋白质含量和面团的湿面筋含量、吸水率和最大拉伸阻力没有显著影响,但对小麦籽粒的硬度和面团沉降值、稳定时间、拉伸面积和延展性有一定影响,其效应在小麦品种间存在一定差异.     

Grain cadmium and zinc concentrations in wheat as affected by genotypic variation and potassium chloride fertilization

Thirteen bread wheat (Triticum aestivum L.) and two durum wheat (Triticum turgidum L. var. durum) cultivars were grown over six site-years to identify differences in grain Cd and Zn concentrations, as affected by genotypic variation and soil application of potassium chloride (KCl) fertilizer. Application of KCl fertilizer did not consistently affect grain Cd concentration of wheat cultivars, but increased average grain yield and decreased average grain Zn in 4 of 6 site-years. However, soil type and year had significant effects on grain Cd and Zn, indicating a strong environmental effect on grain quality. Grain concentrations of Cd and Zn were generally lower for the clay loam (CL) than the fine sandy loam (FSL) soils. The wheat cultivars showed significant genotypic differences in grain concentrations of Cd and Zn, suggesting the potential of breeding to reduce Cd and increase Zn concentrations in grain. The two durum cultivars contained high concentrations of Cd but not Zn compared to the bread wheat. The interaction between cultivars and site-years was significant for grain Zn, but not for grain Cd, suggesting that grain Cd is a more stable trait than grain Zn across environments. Grain Zn and Cd were not related to each other but they both correlated negatively with grain yield. The lack of relationship between Zn and Cd suggests that breeding for enhanced Zn concentration can be attained without necessarily affecting grain Cd concentration. The negative relationship between Cd and Zn concentration and dry matter yield was likely the result of biological dilution, suggesting that genetic improvement leading to increased yield may concurrently decrease mineral concentration. Results of this study are useful to improve the mineral composition of wheat used for human consumption through the development of cultivars and use of agronomic management practices that increase Zn and/or reduce Cd concentrations in wheat grain.     

QTL Analysis for Grain Iron and Zinc Concentrations in Two O. nivara Derived Backcross Populations

Identification of quantitative trait loci (QTLs) for grain mineral elements can assist in faster and more precise development of micronutrient dense rice varieties through marker-assisted breeding. In the present study, QTLs were mapped for Fe and Zn concentrations in two BC₂F₃ mapping populations derived from the crosses of O. sativa cv Swarna with two different accessions of O. nivara. In all, 10 and 8 QTLs were identified for grain Fe and Zn concentrations in population 1, and 7 and 5 QTLs were identified in population 2, respectively. Eighty percent of the QTLs detected in both populations were derived from O. nivara. Five QTLs for Fe and three QTLs for Zn explained more than 15% phenotypic variance either in interval or composite interval mapping. The locations of O. nivara derived QTLs such as qFe2.1, qFe3.1, qFe8.2 and qZn12.1 were consistently identified in both the populations. Epistatic interaction was observed only between RM106 and RM6 on chromosome 2 and between RM22 and RM7 on chromosome 3 for Fe concentration in population 1. Sixteen candidate genes for metal homeostasis were found to co-locate with 10 QTLs for Fe and Zn concentrations in both the populations. Most of the Fe and Zn QTLs were found to co-locate with QTLs for grain yield and grain quality traits. Some of the major effect QTLs identified can be used to improve rice grain Fe and Zn concentrations.