Relationships among important traits in the nitrogen economy of winter wheat

Identification and utilization of important attributes in the nitrogen economy of wheat (Triticum aestivum L.) should provide a basis for increasing grain protein percentage (GPP). The objectives of this study were to determine the magnitude of genetic variability of some factors important in the nitrogen economy of wheat, their relationship to one another, and their influence on grain yield (GY) and GPP. Twenty‐five hard red winter wheat genotypes representing a wide range of GY, GPP, and plant stature were grown in field trials over a 2‐year period. Significant differences were found for harvest index (HI) and nitrogen harvest index (NHI). Total nitrogen at anthesis (TNA), total nitrogen at maturity (TNM), and biological yield (BY) did not differ significantly. GPP was positively correlated with TNM and BY and negatively correlated with TNA, HI, and GY. GPP was not correlated with NHI, however, stepwise regression of GPP and grain protein yield revealed NHI as a common component, with a positive coefficient. In addition, NHI was positively correlated with GY. Selection of parents with complementary traits for nitrogen‐use efficiency may allow for simultaneous increases in GY and GPP.     

不同冬小麦品种氮素吸收运转特性及其与子粒蛋白质含量的关系

选用济南17、鲁麦22、泰山021三个产量水平相近,品质不同的冬小麦品种,利用15N同位素示踪技术研究氮素吸收运转特性及其与子粒蛋白质含量的关系。结果表明,小麦植株一生所吸收的氮素,72.51%～73.57%来自土壤氮,26.43%～27.49%来自肥料氮;其中11.43%来自底施氮,15.60%来自追施氮。开花期肥料氮和土壤氮在济南17中的积累量最高,泰山021最低,鲁麦22介于其间。开花后营养器官中积累的氮素向子粒转移,对子粒氮素积累的贡献为叶片>茎+叶鞘>颖壳+穗轴,品种间比较,鲁麦22转移率最高,泰山021最低,济南17介于其间。基于以上生理原因,鲁麦22最终获得最高子粒蛋白质含量。     

Partitioning of phosphorus in different height isolines of winter wheat

Wheat (Triticum aestivum L.) grain yields and composition are influenced greatly by P and its interactions with other nutrients. Because most P in grain, like N, is remobilized from vegetative parts, high harvest index of dwarf wheats may adversely influence partitioning of P to grain. Isogenic tall, single semidwarf, and double dwarf ‘Pawnee’ wheat lines were used to characterize P partitioning, P nutrition before and after anthesis, and relationship between P and N. Plants were grown in hydroponic cultures with three P levels; the first study determined P, N, and dry matter accumulation from anthesis to maturity, the second study determined the effect of withholding P after anthesis on P, N, and dry matter partitioning during grain development. Plants continued to absorb P when it was available after anthesis, but grain growth was influenced more by P nutrition before anthesis than after anthesis. Leaf blades, sheaths, and stems were major sources of P for grain growth when the nutrient was withheld and major sites of P accumulation when the nutrient was supplied after anthesis. Content of N in plants was favored by ample P levels. Dwarfing genes increased harvest index, but had little effect on P partitioning because of differences in dry matter accumulation.     

冬小麦氮平衡指数与籽粒蛋白质含量空间结构及关系

氮素的吸收对其最终籽粒蛋白质含量具有重要的影响。该研究以冬小麦为研究对象,运用地质统计学方法研究分析了冬小麦胁迫荧光参数氮平衡指数(nitrogen balance index,NBI)与籽粒蛋白质的空间结构并且建立了半方差函数。采用指示值等值线法分析了4个生育阶段的综合氮平衡指数(NBI)与籽粒蛋白质含量的关系。研究结果表明:氮平衡指数(NBI)与籽粒蛋白质含量数据符合正态分布;具有明显的区域化变量特征和较好的空间结构;冬小麦各生育期胁迫荧光参数氮平衡指数(NBI)与籽粒蛋白质含量的相关系数均表现较好,在灌浆中后期达到最大值(r=0.828);适宜氮平衡指数维持较长时间有利于较高籽粒蛋白质含量的形成,且综合氮平衡指数与籽粒蛋白质含量表现出相同的空间分布。该研究确定的冬小麦氮平衡指数(NBI)与籽粒蛋白质含量的空间结构和关系为作物大田氮肥管理、籽粒蛋白质预测等提供参考。     

Optimizing row spacing in wheat cultivars differing in tillering and stature for higher productivity

Five wheat cultivars differing in tillering capacity and stature, Sahar-2006 (SH-06) (tall and low tillering), Faisalabad-2008 (FSD-08) (tall and low tillering), Lassani-2008 (LS-08) (medium stature and low tillering), Abdulstar-2002 (AS-02) (medium stature and high tillering) and Triple dwarf-1 (TD-1) (dwarf and low tillering), were planted in 10-, 20- and 30-cm spaced rows in a two-year study with same plant density. Higher grain yield in 20-cm spaced rows during both years and 30-cm spaced rows during the first year of the study in tall and low tillering wheat cultivars was attributed to more productive tillers, grains per spike and 1000-grain weight. However, the higher number of productive tillers resulted in better grain yield of the dwarf and low tillering cultivar under narrow row spacing. Higher leaf area index and crop growth rate were observed in 20- and 30-cm spaced rows 90 days after sowing, thereafter a drastic decrease was observed in 30-cm spaced rows. In conclusion, for harvesting maximum wheat productivity, tall and low tillering cultivars should be planted in 20-cm spaced rows. Medium stature and low tillering cultivars may be planted in 20 or 30-cm spaced rows, whereas low tillering dwarf cultivars should be planted in 10-cm spaced rows.     

ASD Field Spec3野外便携式高光谱仪诊断冬小麦氮营养

氮素营养诊断关键在于氮营养指数(nitrogen nutrient index,NNI)预测。对于冬小麦氮营养指数预测模型而言,如何选取预处理方法和建模方法不一而足,不同预处理和模型选取对预测结果精度的影响程度目前还不清楚。该研究以ASD Field Spec3野外便携式高光谱仪采集乐陵市冬小麦冠层高光谱数据,采用10种光谱预处理方法并结合3种模型(偏最小二乘回归、BP神经网络和随机森林算法)建立多种冬小麦氮营养指数高光谱预测模型。对比模型预测精度表明最佳的高光谱建模方法为随机森林算法结合SG卷积平滑预处理所建模型(预测集R2=0.795,RMSE=0.125,RE=11.7%)精度高、可靠性强,是筛选出最佳的冬小麦氮营养指数高光谱预测模型。该研究结果对冬小麦氮营养指数高光谱预测建模具有科学价值,为筛选最优高光谱预处理方法和预测模型提供技术参考。     

半湿润农田生态条件下施氮对不同冬小麦品种氮素转移的影响

在年均降水量632mm的黄土高原南部半湿润红油土上进行田间试验,以NR.94059、430、偃师9号、小偃6号、陕229、西农2208、矮丰3号和商188为供试材料,研究在不施氮和施氮(N.90.kg/hm2)条件下不同冬小麦品种灌浆期氮素转移的差异。结果表明,小麦氮转移量(NT)和氮转移效率(NTE)在不同品种间差异不显著,而茎鞘氮转移效率(NTES)在品种间存在显著差异(P0.05),施氮对这些指标没有显著影响。转移氮对子粒氮贡献率(NCR)在不同品种间差异显著(P0.05),而施氮对NCR没有显著影响。不同品种间NCR从大到小的顺序为NR9405、西农2208、矮丰3号、商188、偃师9号、9430、小偃6号、陕229。氮收获指数(NHI)具有显著的品种差异,NHI从大到小的顺序为陕229、9403、矮丰3号、西农2208、偃师9号、商188、NR9405、小偃6;陕229和9403的NHI超过80%,分别为81.76%和81.02%;小偃6号仅为76.62%。不同品种的氮素利用效率(NUE)存在极显著差异(P0.001),以偃师9号最高,为37.25.g/g,小偃6号最低,为29.29.g/g;施氮对NHI和NUE无显著影响。子粒含氮量与NUE间呈极显著负相关关系(r=0.918,P0.001),表明对同一个品种难以同时提高NUE和子粒含氮量。     

基于开花期氮素营养指标的冬小麦籽粒蛋白质含量遥感预测

籽粒蛋白含量(grain protein content,GPC)是衡量小麦品质的重要指标,及时准确的预测小麦GPC有利于小麦的分类收割和分级存储。为了能够选择一个合适的氮素营养指标作为中间变量来反演小麦GPC,该文研究分别以开花期植株氮素累积量(plant nitrogen accumulation,PNA)、植株氮素含量(plant nitrogen content,PNC)、叶片氮素累积量(leaf nitrogen accumulation,LNA)和叶片氮素含量(leaf nitrogen content,LNC)4个氮素营养指标为中间变量,并运用支持向量机(support vector machines,SVM)算法实现4个氮素营养指标的估测,最后构建及评价基于开花期"植被指数(vegetation index,VI)-氮素营养指标(nitrogen nutrition index,NNI)-GPC"模式的冬小麦GPC预测模型。结果表明:1)通过分析植被指数与氮素营养指标的相关性,选择植被指数MSAVI、PSRI、DVI、RDVI和GNDVI作为氮素营养指标模型的构建变量;2)运用SVM方法构建的VI-NNI模型中LNC的建模精度与验证精度相对最优,其建模决定系数(coefficient of determination,R~2)和验证集标准均方根误差(normalized root mean squared error,n RMSE)及验证标准化平均误差(normalized average error,NAE)分别为0.820、9.553%、-1.4%,验证结果稳定性较好;3)构建NNI-GPC模型中PNC的建模精度与验证精度相对最好,其建模R~2和验证n RMSE及NAE分别为0.653、9.843%、-0.3%;4)最终构建的VI-NNI-GPC模型中,以开花期PNC为中间变量的模型建模及反演精度最好,其建模R~2和验证n RMSE及NAE分别为0.631、8.564%、-0.9%。以氮素营养指标为中间变量的GPC遥感反演是可行的,并且比较4个氮素营养指标为中间变量反演GPC,PNC具有较高精度的预测结果,为精确反演GPC提供一个可靠的依据,具有一定的应用前景。     

两种冬小麦对铝毒响应的敏感性差异研究

A experiment was carried to evaluate the effects of Al on growth, accumulations of free proline and amino acid in 2 wheat cultivars (Triticum aestivum L.), Yangmai No.5 and Jian 864, differing in Al sensitivity. Plants grew initially in a nutrient solution without Al for 13 days before the addition of Al and finally in a nutrient solution containing 0.5mmol Al (L^-1) for 19 days. The results showed that there were marked decreases in dry weight, relative growth rate (RGR) and net assimilation rate (NAR) of Al-treated seedlings compared with control plants. The Al effects were more evident in Yangmai No.5 than Jian 864. Leaf area ratio(LAR) was little affected by Al. RGR was highly correlated with NAR rather than LAR. Aluminum increased the concentrations of free proline and total free amino acid in shoots of both the cultivars. The increases were greater in Yangmai No.5 than in Jian 864. The percentage of free proline in total amino acid in shoots was not affected by Al treatment. It was possible that accumulation of proline was merely a symptom of Al injury. The concentrations of total nitrogen in Al-treated plants did not significantly differ from those of control plants. Nitrate reductase activity (NRA) in leaves was severely decreased by Al, and a greater decrease was noted in Yangmai No.5 than in Jian 864, but NRA in roots of both the cultivars was not affected. The decreases in NRA might be an indirect (accumulation of amino acid) rather than a direct result of Al toxicity.     

铜氮配施对冬小麦籽粒产量和蛋白质含量的影响

在豫中潮土区通过田间裂区试验研究了铜、氮配施对冬小麦籽粒产量和蛋白质的影响。结果表明,氮肥对冬小麦籽粒产量和蛋白质产量影响达极显著水平,对蛋白质含量影响不显著。铜肥对籽粒产量和蛋白质产量的影响都达到极显著水平,对籽粒蛋白质含量影响达显著水平。氮、铜交互对冬小麦籽粒产量和蛋白质产量影响达极显著差异,对蛋白质含量影响也达显著差异。综合考虑产量和蛋白质因素,本试验条件下,铜、氮配施以N1Cu2处理(即施氮120 kg.hm-2,施铜45 kg.hm-2)为适宜的铜、氮配施比例。     

基于氮素营养指数的冬小麦籽粒蛋白质含量遥感反演

基于遥感实现小麦籽粒蛋白质含量提早估测对农业生产具有重要意义。为提高预测小麦籽粒蛋白质含量的准确度,该研究引入能更好反映作物氮素营养状况的农学参数－氮素营养指数,作为衔接遥感信息与产终籽粒蛋白质含量的桥梁。在田间试验的基础上,探讨氮素营养指数与其他农学参数在诊断籽粒蛋白质含量上的优劣,并基于“遥感参数－氮素营养指数－籽粒蛋白质含量”间关系,利用主成分回归算法构建估测籽粒蛋白质含量的遥感反演模型。结果表明,相比于其他参数,冬小麦旗叶期氮素营养指数能更好的反映产终籽粒蛋白质含量;以氮素营养指数为中间变量,所建遥感反演模型能准确预测小麦籽粒蛋白质含量,模型的预测决定系数为0.48,预测标准误差为0.38%,相对误差为2.32%。     

不同灌溉条件下不同类型冬小麦产量水分利用效率差异原因分析

以旱地品种"西峰20"和"晋麦47"、水旱兼用型品种"石家庄8 号"、高水肥地品种"石4185"和"科农9204"5 个冬小麦品种为材料, 通过田间不同灌溉处理试验研究了不同抗旱类型冬小麦品种收获指数和群体水分利用效率对产量水分利用效率的影响差异。结果表明: 不同抗旱类型的小麦在不同灌溉处理下, 产量水分利用效率(WUE_y)以及变化趋势存在显著差异。旱地冬小麦品种WUE_y 和收获指数(HI)显著低于水地品种和水旱兼用型品种。不同品种间WUE_y 最大相差42.01%, HI 相差25.91%。HI 和群体水分利用效率(WUE_bm)与WUE_y 呈显著正相关关系。株高与HI 呈显著负相关关系(R²=0.574)。在不灌溉条件下, 品种间WUE_y 差异源自HI 的差异; 而在补充灌溉条件下, 品种间WUE_y 的差异源自WUE_bm 和HI 的共同作用。说明不同抗旱类型的小麦对不同灌溉处理的响应方式和适应策略不同。旱地品种在干旱胁迫条件下, 主要靠增加WUE_bm 来提高WUE_y; 而水地品种和水旱兼用型品种在补充灌溉中凭借较高的WUE_bm 和HI 共同作用提高WUE_y。     

Influence of nitrogen application rate and timing on grain protein composition and gluten strength in Swedish wheat cultivars

The influence of nitrogen (N) fertilizer application rate (0 vs. 70 vs. 140 kg N ha^–1) and timing (early = at sowing vs. late = at sowing and before heading) on the amount of protein groups, amount and size distribution of mono‐ and polymeric proteins, and gluten strength was investigated in one set of wheat cultivars (Triticum aestivum L.). Due to their genetic background, the cultivars had different protein concentrations and gluten strengths. Despite this, all of them reacted similarly on rate and timing of nitrogen application. The rate of nitrogen fertilizer increased the variation in protein concentration, gluten strength, and also the variation in most of the investigated protein components. Higher nitrogen fertilizer rate increased protein concentration, decreased gluten strength, and increased the total amount of glutenins and gliadins as well as the amounts of most mono‐ and polymeric proteins. Timing of fertilizer did not influence protein concentration. The gluten strength and the relations of proteins were changed by the timing of fertilizer. Early nitrogen feritilizer applications led to higher gluten strength and a higher percentage of total unextractable polymeric protein in the total polymeric protein and large unextractable polymeric protein in the total large polymeric protein, compared to late nitrogen fertilizer applications.     

Prediction of grain protein content in winter wheat through leaf color measurements using a chlorophyll meter

A field trial was conducted over a 3-year period at the Hokkaido Kitami Agricultural Experiment Station to examine whether the grain protein content (GPC) of a winter wheat cultivar (Triticum aestivum L. cv. Chihokukomugi) suitable for Japanese noodle-making could be predicted before harvest. The prediction of the GPC was accurate based on the color of the second leaf (just below the flag leaf) at the end of the emergence of the inflorescence, when nitrogen application was graded. In order to evaluate the reliability of this test, a survey of 95 wheat fields in the eastern part of Hokkaido was also carried out during a 3-year period. The prediction of the GPC for this cultivar based on the color of the second leaf was less accurate across many sites. The results of this survey, however, suggested that the leaf color could be used as an index for ranking the GPC as low or high in relation to processing requirements. When the leaf color value of the second leaf measured with a chlorophyll meter at the end of the emergence of the inflorescence was less than 40, it was predicted that the GPC would be lower than the processing requirement. This index could be applied to the cultivars grown in the eastern part of Hokkaido, except for those grown on peat soils.     

水氮耦合对强筋冬小麦子粒蛋白质和淀粉品质的影响

在高肥力条件下,研究水氮耦合对小麦子粒产量、蛋白质含量及组成、蛋白质质量、淀粉含量及组成和淀粉品质的影响。结果表明,无论施氮与否,灌水均显著提高小麦子粒产量,同时显著降低子粒粗蛋白、单体蛋白及湿面筋含量;但不同灌水量间(W1、W2、W3)差异不显著。在低灌水频次(W0、W1)条件下,施氮具有明显的增产效应;而高灌水频次(W2、W3),施氮的增产效应不显著。随着灌水次数增加,谷蛋白总量保持稳定,而谷蛋白组分产生了显著的变化,其中可溶性谷蛋白含量呈上升趋势,不溶性谷蛋白含量和谷蛋白聚合指数呈下降趋势,粉质仪参数(形成时间和稳定时间)也呈下降趋势。小麦子粒蛋白质含量及组分和子粒品质均因施氮(N.168.kg/hm2)而有不同程度的提高,其中非面筋蛋白(清蛋白和球蛋白)的增加幅度高于面筋蛋白(醇溶蛋白和谷蛋白),可溶性谷蛋白增加幅度高于不溶性谷蛋白,即降低了谷蛋白聚合指数。水氮对子粒的淀粉含量及其组成的影响存在明显的交互效应。在不施氮肥条件下,随灌水次数增加,支链淀粉和总淀粉含量呈上升趋势;施氮条件下,各灌水处理(W1、W2、W3)的总淀粉和支链淀粉含量均显著高于不灌水处理(W0),但各灌水处理间差异不显著。随灌水次数增加,直链淀粉含量和直/支比均呈下降趋势,黏度仪指标(峰值黏度、稀值、最终黏度和反弹值)均呈上升趋势。施氮在低灌水频次(W0、W1)条件下促进支链淀粉的合成,同时降低直链淀粉含量和直/支比;高灌水频次(W2、W3)条件下则相反。     

皖草2号和墨西哥玉米氮肥利用效率分析

采用15N同位素示踪技术,进行了皖草2号和墨西哥玉米两种饲料作物对氮素的吸收、积累、分配规律以及氮素利用特性的研究。结果表明,生育期内两者的氮积累量逐渐增加;氮在叶片中的分配比例最高,且随刈割次数的增加逐渐减少,茎鞘中氮分配比例逐渐增加;氮素吸收强度皖草2号逐渐增加,墨西哥玉米呈单峰曲线变化。墨西哥玉米再生草吸收氮素来自肥料的比率为97.6%1～00.0%,在整个生育期呈斜“Z”字型变化;皖草2号逐渐减少。氮肥处理间比较,头茬草一次性施肥处理吸收肥料氮比分次施肥处理分别高18.2%和19.3%;再生草的氮素吸收强度以分次施肥效果较好;氮收获指数两处理间差异不显著。皖草2号各次收获草干重、全氮含量、氮累积量和氮回收率均高于墨西哥玉米,且分次施肥处理高于一次性施肥处理,而墨西哥玉米则相反。生产上皖草2号品种应采用分次施用氮肥,而墨西哥玉米则采用一次性施肥的方式,这样既可提高氮肥利用效率,还可获得优质的牧草。     

旱地不同冬小麦品种氮素营养的叶绿素诊断

通过田间试验研究了叶绿素仪用于西北旱地主栽的10个冬小麦品种氮素营养诊断的效果。结果表明,冬小麦SPAD值与子粒产量、生物学产量有很好的相关性,尤其以拔节期和开花期相关性较高。不同施氮量下的SPAD值有明显的不同,施氮量为180kg/hm2时,SPAD值达到最大。在同一施氮水平下,开花期的SPAD值均最高。拔节期之前冬小麦不同品种间SPAD值的差异较小,拔节期以后差异较大,最大可达9.2个SPAD单位。小偃22在每个时期的SPAD值都最高,并且与陕253、陕229和小偃503之间的差异均达显著水平,而陕253、陕229和小偃503之间的差异不显著。可见,小偃22与其它3个品种对氮素反应分属于不同类型,应根据不同品种类型建立相应的诊断指标。     

施氮量和底追比例对小麦氮素吸收利用及子粒产量和蛋白质含量的影响

在大田栽培条件下,运用15N示踪技术研究了不同施氮量和底追肥比例对小麦氮素利用和子粒产量及蛋白质含量的影响。结果表明,施用氮肥提高了小麦植株的氮素积累量、子粒产量、蛋白质含量和蛋白质产量。相同施氮量条件下增加追肥氮的比例,提高了氮肥农学利用率和吸收利用率,增加了植株地上部器官(子粒+营养器官)中追肥氮、土壤氮的积累量,提高了营养器官中氮素的转运量和开花后氮素的同化量,增加了子粒蛋白质含量。相同的氮素底追肥比例条件下,将240.kg/hm2施氮量降至168.kg/hm2的处理,氮肥农学利用率、氮肥吸收利用率、氮肥偏生产力提高,子粒中土壤氮的积累量增加,植株地上部器官中土壤氮的积累量亦增加,开花后氮素同化量提高,子粒蛋白质含量增加。各施氮处理间子粒产量无显著差异。在本试验条件下,施氮量为168.kg/hm2且全部于拔节期追施是兼顾产量、品质和效益的优化处理。     

Genotypic variation in partitioning of phosphorus in relation to nitrogen and dry matter during wheat grain development

Phosphorus has many similarities to N for plant nutrition, but little is known regarding P partitioning among genotypes and factors that affect it. Experiments were conducted to measure variation in partitioning of P and its relationship to N, dry matter, and yield components of wheat (Triticum aestivum L.). Sixteen cultivars grown under field conditions were sampled at anthesis for P, N, and dry matter and at maturity for the same constituents and for yield components. Relationships among the traits were determined by Spearman rank correlation coefficients. Accumulation of P and dry matter during grain development and grain HI, NHI, and PHI differed significantly among genotypes. Post‐anthesis P, N, and dry matter accumulation correlated positively as did HI, NHI, and PHI, but accumulation of the constituents was not related to their His. The positive associations were attributed to requirement of P and N for growth and their accumulation as reserve compounds in grain. Genotypic variation in PHI may be as useful as variation in HI and NHI for wheat improvement.     

Predicting grain yield and protein content in winter wheat at different N supply levels using canopy reflectance spectra

A field experiment using a split-plot randomized complete block design with three replications was carried out to determine relationships between spectral indices and wheat grain yield （GY）, to compare the performance of four vegetation indices （VIs） for GY prediction, and to study the feasibility of VI to estimate grain protein content （GPC） in winter wheat. Two typical winter wheat （Triticum aestivum L.） cultivars ＇Xuzhou 26＇ （high protein content） and ＇Huaimai 18＇ （low protein content） were used as the main plot treatments and four N rates, i.e., 0, 120, 210, and 300 kg N ha^-1, as the sub-plot treatments. Increasing soil N supply significantly increased GY and GPC （P ≤ 0.05）. For the two cultivars combined, significant and positive correlations were found between four VIs and GY, with the strongest relationship observed when using the green ratio vegetation index （GRVI） at mid-filling. Cumulative VI estimates improved yield predictions substantially, with the best interval being heading to maturity stage. Similar results were found between VI and grain protein yield. However, when using cumulative VI, GPC showed no significant improvement. The strong relationship between leaf N status and GPC （R2 =0.9144 for ＇Xuzhou 26＇ and R2 = 0.8285 for ＇Huaimai 18＇） indicated that canopy spectra could be used to predict GPC. The strong fit between estimated and observed GPC （R2 = 0.7939） indicated that remote sensing techniques were potentially useful predictors of grain protein content and quality in wheat.