小麦是重要的粮食作物, 其微量元素含量高低直接影响人体健康。明确我国主要麦区小麦籽粒微量元素含量水平, 对优化小麦微量元素营养品质, 保障居民营养健康有重要意义。于2016—2020年, 在我国17个小麦主产省区采集分析了1112份小麦及土壤样品, 参考《中国营养学会人体微量元素摄入标准》和美国环境保护署健康风险评估方法, 结合我国居民饮食特点, 推荐了小麦籽粒微量元素适宜含量范围, 并以此评价了我国小麦的微量元素营养状况。研究发现, 我国小麦籽粒铁含量平均为43.8 mg kg^-1, 72.9%样本低于铁的推荐量下限50 mg kg^-1, 所有样本铁含量均低于推荐量上限140 mg kg^-1; 籽粒锰含量平均为43.0 mg kg^-1, 仅4.1%样本低于推荐锰含量下限22 mg kg^-1, 但23.7%样本高于推荐上限值50 mg kg^-1; 籽粒铜含量平均为4.6 mg kg^-1, 7.6%样本低于推荐量下限3 mg kg^-1, 所有样本铜含量均低于推荐量上限10 mg kg^-1; 籽粒锌含量平均为31.4 mg kg^-1, 85.8%的样本低于推荐量下限40 mg kg^-1, 仅4.1%样本高于50 mg kg^-1的推荐量上限; 籽粒硼含量平均为1.2 mg kg^-1, 低于推荐量下限0.8 mg kg^-1的样本占29.2%, 所有样本均低于推荐值上限10 mg kg^-1; 籽粒钼含量平均为0.5 mg kg^-1, 18.8%的样本钼含量低于推荐量下限0.2 mg kg^-1, 仅有0.4%样本钼含量高于推荐值上限2 mg kg^-1。我国小麦籽粒微量元素含量也存在区域间变异, 其中, 铁、锌含量普遍偏低, 部分地区硼、钼含量不足, 而锰含量偏高, 铜含量基本在推荐范围内。

Increasing zinc (Zn) concentration in wheat grain is an important global challenge due to high incidence of Zn deficiency in human populations. In this study, a two-year field experiment was conducted to investigate the effects of foliar ZnSO4 combined with various biostimulants (fulvic acid (FA), seaweed extract (SE), amino acids (AA), and microbial incubates (MI)) on Zn concentration and bioavailability in wheat grain under different soil nitrogen (N) levels (0, 120, and 240 kg N/ha). Grain Zn concentration and bioavailability were significantly enhanced by foliar Zn plus various biostimulants and soil N supply. Compared to foliar Zn alone, foliar Zn + FA resulted in 16% increase in grain Zn, mainly from insoluble Zn increases, while foliar Zn + AA caused 11% increase in grain Zn, mainly from soluble (at N0) and insoluble Zn increases (at N120). Foliar Zn + FA and Zn + AA generally resulted in higher Zn bioavailability than foliar Zn alone. Additionally, N concentration and Fe concentration and bioavailability in grain were enhanced with foliar Zn + AA and soil N application. Thus, foliar ZnSO4 plus FA and AA under optimal soil N rate (120 kg N/ha) can be an effective and economically friendly approach for achieving agronomic biofortification.

We aim to develop a meaningful single-source reference for management and organization scholars interested in using bibliometric methods for mapping research specialties. Such methods introduce a measure of objectivity into the evaluation of scientific literature and hold the potential to increase rigor and mitigate researcher bias in reviews of scientific literature by aggregating the opinions of multiple scholars working in the field. We introduce the bibliometric methods of citation analysis, co-citation analysis, bibliographical coupling, co-author analysis, and co-word analysis and present a workflow for conducting bibliometric studies with guidelines for researchers. We envision that bibliometric methods will complement meta-analysis and qualitative structured literature reviews as a method for reviewing and evaluating scientific literature. To demonstrate bibliometric methods, we performed a citation and co-citation analysis to map the intellectual structure of the Organizational Research Methods journal.

To better understand the effects of agronomic practices on yield–nutrition relationships in wheat (Triticum aestivum L.) grains for Zn biofortification while improving yields simultaneously, effects of different soil fertilization and different drone-based foliar spraying treatments were investigated in calcareous soils. For soil fertilization, the incorporation of Zn or increasing the N/P ratio in compound fertilizers proved to be effective in enhancing grain Zn concentrations and yields. However, the overall effects of soil fertilization are limited, with a maximal yield increase of only 7.0% and a maximal increase of the grain Zn concentration from 19.4 to 27.0 mg/kg, which is far below the target biofortification value of 40–50 mg/kg. Unfortunately, there was a negative side effect, which decreased Fe and Mn concentrations and the Fe bioavailability. Notably, drone-based foliar Zn sprayings increased grain yields from the control 7.5 t/ha to 8.6 t/ha at ZnO treatment by 12.0% and 8.8 t/ha at ZnSO4·7H2O treatment by 17.3%. Meanwhile, grain Zn concentrations were increased from the control 33.5 mg/kg to 41.9 mg/kg at ZnO treatment by 25.1% and 43.6 mg/kg at ZnSO4·7H2O treatment by 30.1%. Treatments with ZnSO4·7H2O increased grain Zn concentrations and accumulation more so than ZnO, indicating the importance of chemical Zn forms in determining the effectiveness of foliar spraying. Moreover, foliar Zn sprayings simultaneously increased grain concentrations and accumulation of Fe, Mn and Cu, demonstrating multiple benefits. There were positive correlations between Zn and Fe, Mn or Cu, indicating synergistic interactions. Compared to micronutrients, concentrations of grain macronutrients (N, P, K, Ca and Mg) were less affected. Thus, a dual-benefit in both grain yields and micronutrient (particularly for Zn) nutrition could be effectively achieved through appropriate soil fertilization and foliar Zn spraying. These findings provide a better understanding of the yield–nutrition relationship among wheat grain yields, Zn and other nutrient elements for a better integrated manipulation to achieve a win–win situation in yield and nutrition.

\nFoliar N/P plus Zn caused much greater grain nutritional quality.

Humans require more than 22 mineral elements, which can all be supplied by an appropriate diet. However, the diets of populations subsisting on cereals, or inhabiting regions where soil mineral imbalances occur, often lack Fe, Zn, Ca, Mg, Cu, I or Se. Traditional strategies to deliver these minerals to susceptible populations have relied on supplementation or food fortification programs. Unfortunately, these interventions have not always been successful. An alternative solution is to increase mineral concentrations in edible crops. This is termed 'biofortification'. It can be achieved by mineral fertilization or plant breeding. There is considerable genetic variation in crop species that can be harnessed for sustainable biofortification strategies. Varieties with increased mineral concentrations in their edible portions are already available, and new genotypes with higher mineral densities are being developed.

Micronutrient malnutrition affects over 2 billion people in the developing world. Iron (Fe) deficiency alone affects >47% of all preschool aged children globally, often leading to impaired physical growth, mental development, and learning capacity. Zinc (Zn) deficiency, like iron, is thought to affect billions of people, hampering growth and development, and destroying immune systems. In many micronutrient‐deficient regions, wheat is the dominant staple food making up >50% of the diet. Biofortification, or harnessing the powers of plant breeding to improve the nutritional quality of foods, is a new approach being used to improve the nutrient content of a variety of staple crops. Durum wheat in particular has been quite responsive to breeding for nutritional quality by making full use of the genetic diversity of Fe and Zn concentrations in wild and synthetic parents. Micronutrient concentration and genetic diversity has been well explored under the HarvestPlus biofortification research program, and very positive associations have been confirmed between grain concentrations of protein, Zn, and Fe. Yet some work remains to adequately explain genetic control and molecular mechanisms affecting the accumulation of Zn and Fe in grain. Further, evidence suggests that nitrogen (N) nutritional status of plants can have a positive impact on root uptake and the deposition of micronutrients in seed. Extensive research has been completed on the role of Zn fertilizers in increasing the Zn density of grain, suggesting that where fertilizers are available, making full use of Zn fertilizers can provide an immediate and effective option to increase grain Zn concentration, and productivity in particular, under soil conditions with severe Zn deficiency.

Zinc (Zn) deficiency associated with low dietary intake is a well-documented public health problem, resulting in serious health and socioeconomic problems. Field experiments were conducted with wheat to test the role of both soil and foliar application of ZnSO4 in Zn concentration of whole grain and grain fractions (e.g., bran, embryo and endosperm) in 3 locations. Foliar application of ZnSO4 was realized at different growth stages (e.g., stem elongation, boot, milk, dough stages) to study the effect of timing of foliar Zn application on grain Zn concentration. The rate of foliar Zn application at each growth stage was 4 kg of ZnSO4·7H2O ha(-1). Laser ablation (LA)-ICP-MS was used to follow the localization of Zn within grain. Soil Zn application at a rate of 50 kg of ZnSO4·7H2O ha(-1) was effective in increasing grain Zn concentration in the Zn-deficient location, but not in the locations without soil Zn deficiency. In all locations, foliar application of Zn significantly increased Zn concentration in whole grain and in each grain fraction, particularly in the case of high soil N fertilization. In Zn-deficient location, grain Zn concentration increased from 11 mg kg(-1) to 22 mg kg(-1) with foliar Zn application and to 27 mg kg(-1) with a combined application of ZnSO4 to soil and foliar. In locations without soil Zn deficiency, combination of high N application with two times foliar Zn application (e.g., at the booting and milk stages) increased grain Zn concentration, on average, from 28 mg kg(-1) to 58 mg kg(-1). Both ICP-OES and LA-ICP-MS data showed that the increase in Zn concentration of whole grain and grain fractions was pronounced when Zn was sprayed at the late growth stage (e.g., milk and dough). LA-ICP-MS data also indicated that Zn was transported into endosperm through the crease phloem. To our knowledge, this is the first study to show that the timing of foliar Zn application is of great importance in increasing grain Zn in wheat, especially in the endosperm part that is the predominant grain fraction consumed in many countries. Providing a large pool of Zn in vegetative tissues during the grain filling (e.g., via foliar Zn spray) is an important practice to increase grain Zn and contribute to human nutrition.

Mineral phosphorus (P) fertilizers support high crop yields and contribute to feeding the teeming global population. However, complex edaphic processes cause P to be immobilized in soil, hampering its timely and sufficient availability for uptake by plants. The resultant low use efficiency of current water-soluble P fertilizers creates significant environmental and human health problems. Current practices to increase P use efficiency have been inadequate to curtail these problems. We advocate for the understanding of plant physiological processes, such as physiological P requirement, storage of excess P as phytate, and plant uptake mechanisms, to identify novel ways of designing and delivering P fertilizers to plants for improved uptake. We note the importance and implications of the contrasting role of micronutrients such as zinc and iron in stimulating P availability under low soil P content, while inhibiting P uptake under high P fertilization; this could provide an avenue for managing P for plant use under different P fertilization regimes. We argue that the improvement of the nutritional value of crops, especially cereals, through reduced phytic acid and increased zinc and iron contents should be among the most important drivers toward the development of innovative fertilizer products and fertilization technologies. In this paper, we present various pathways in support of this argument. Retuning P fertilizer products and application strategies will contribute to fighting hunger and micronutrient deficiencies in humans. Moreover, direct soil P losses will be reduced as a result of improved P absorption by plants.

【目的】探讨潜在缺锌石灰性土壤上，不同水分管理措施及氮肥用量下锌与氮磷肥配合喷施对冬小麦籽粒Zn含量及生物有效性的影响，为提高小麦籽粒锌营养品质进而缓解人体缺锌问题提供理论与实践依据。【方法】以小偃22为试材，于2010年10月至2012年6月，在陕西关中地区进行田间再裂区定位试验，试验设置主处理为3个水分管理措施，分别为常规种植、覆膜种植（垄上覆膜沟内播种）、补灌种植（小麦越冬期灌水40 mm）；副处理为3个施氮水平，N素用量分别为0、120、240 kg·hm^-2，副副处理为4个叶面喷肥处理，分别为CK（喷蒸馏水）、喷Zn（0.3% ZnSO₄·7H₂O）、喷Zn+N（0.3% ZnSO₄·7H₂O+1.7% CO(NH₂)₂）、喷Zn+P（0.3% ZnSO₄·7H₂O+0.2% KH₂PO₄）。通过测定分析籽粒Zn、P以及蛋白质含量，探讨锌与氮磷肥分别配合喷施对小麦锌营养品质的影响。【结果】与常规水分管理相比，越冬期补灌可提高小麦籽粒Zn含量，而覆膜在2011—2012生长季籽粒Zn含量显著降低；补灌在2011—2012年小麦籽粒P/Zn摩尔比显著降低，降低幅度为6.8%。与不施氮相比，施氮120和240 kg·hm^-2在2011—2012生长季均显著提高了籽粒Zn含量，提高幅度分别为2.3%和7.4%；施氮120或240 kg·hm^-2小麦籽粒P/Zn摩尔比均显著降低，且随施氮量的增加降低幅度增大，施氮量为240 kg·hm^-2时，两季平均降低幅度分别为33.0%和25.5%；施氮处理的籽粒蛋白质含量显著提高，籽粒P含量显著降低。与喷水（CK）相比，喷肥处理（喷Zn、喷Zn+N和喷Zn+P）小麦籽粒锌含量分别由对照处理的20.6 mg·kg^-1提高到了40.3、39.6和33.7 mg·kg^-1，两季平均提高幅度分别为95.5%、92.2%和63.5%，表明锌肥与氮肥或磷肥分别配合喷施均是提高籽粒Zn含量的重要农艺措施。喷Zn+N处理提高小麦籽粒锌含量的效果优于喷Zn+P处理，籽粒平均锌含量提高5.9 mg·kg^-1；喷Zn、喷Zn+N和喷Zn+P处理的籽粒P/Zn摩尔比均显著降低，两季平均降低幅度分别为48.5%、47.6%和38.5%，其中喷Zn处理在补灌且施氮240 kg·hm^-2时籽粒P/Zn摩尔比降低幅度达66.7%；与喷水相比，喷Zn+N处理的籽粒蛋白质含量显著提高，提高幅度两季分别为5.4%和11.2%。与常规不施氮相比，喷肥处理在补灌施氮条件下籽粒富锌效果较好。不同水氮管理下锌与氮磷肥配合喷施，在补灌条件下施氮量为120 kg·hm^-2时喷Zn+N处理对提高籽粒Zn含量和Zn生物有效性的效果较好，与常规不施氮喷水处理相比，提高幅度分别为110.1%和64.5%，同时籽粒蛋白质含量也显著提高。【结论】在潜在缺锌土壤地区，适宜的水分管理措施（冬季补灌）及增施氮肥均表现出一定的提高籽粒Zn含量及Zn生物有效性的作用，锌与氮肥及锌与磷肥分别配合喷施均对改善籽粒锌营养品质有显著促进作用，且锌肥与氮肥配合喷施效果优于锌肥与磷肥配合喷施。因此，综合考虑经济效益与作物锌营养品质，在适时灌溉及适量施氮条件下锌肥与氮肥混合喷施将是潜在缺锌土壤上一种快速提高小麦籽粒锌营养品质的有效途径，具有在潜在缺锌土壤地区甚至是其它缺锌地区广泛推广的前景。

【目的】叶面喷锌（Zn）是提高小麦籽粒锌含量进而解决人体缺锌问题的有效农艺措施。探明不同施氮（N）量下叶面喷锌后小麦全粒及面粉中的富锌效果及对蛋白组分含量的影响。【方法】基于长期定位试验,于2018—2020年连续进行了两年裂区田间试验。以基施不同用量氮肥（N₀、N₁₂₀、N₂₄₀,施N量分别为0、120、240 kg∙hm^-2）为主区,副区为灌浆前期喷施锌肥处理（Zn₀、Zn₁,分别为喷H₂O、喷0.4% ZnSO₄·7H₂O）,测定了灌浆前期和成熟期各部位锌含量、叶片等营养器官中锌向籽粒的转移量及分配、籽粒和面粉中蛋白质及其组分含量。【结果】与N₀相比,N₁₂₀和N₂₄₀处理籽粒产量显著提高,增幅达88%—114%,但N₁₂₀和N₂₄₀处理之间并无显著差异。叶面喷锌均能显著提高小麦籽粒和面粉锌含量且籽粒达富锌标准,而不受施氮量的影响,其中,N₁₂₀、N₂₄₀处理小麦籽粒锌含量分别比N₀处理提高0.95和1.12倍。与N₀相比,施用氮肥均提高了小麦灌浆前期叶片等营养器官中氮、锌向籽粒的转移量,但降低了二者的转移比例,其中氮转移比例由60.2%下降至48.6%,锌由55.4%下降至42.3%。无论喷锌与否,氮、锌向籽粒的转移量及成熟期籽粒中氮、锌含量均呈显著线性正相关,且喷锌时氮、锌协同效应更为显著。与灌浆前期相比,成熟期小麦籽粒和面粉中储藏蛋白（醇溶蛋白和谷蛋白）含量显著增加,约占蛋白含量的80%—84%。施氮对籽粒和面粉中醇溶蛋白和谷蛋白含量提升幅度高于清蛋白和球蛋白,且以谷蛋白最大,而喷锌不影响籽粒和面粉中蛋白质及其组分含量,但在Zn₁条件下,施氮对籽粒和面粉中谷蛋白含量的提高幅度高于Zn₀条件下,分别提升37.5%和38.1%。【结论】叶面喷锌能够实现籽粒富锌,但不影响籽粒和面粉中蛋白质及其组分含量,表明籽粒和面粉中存在足够的用于锌储存的蛋白质库。因此在潜在缺锌石灰性土壤上,通过合理施用氮肥结合小麦灌浆前期叶面喷锌,能在保证小麦高产稳产的同时提高籽粒氮、锌营养品质。

Understanding the molecular basis of zinc (Zn) uptake and transport in staple cereal crops is critical for improving both Zn content and tolerance to low-Zn soils. This study demonstrates the importance of group F bZIP transcription factors and ZIP transporters in responses to Zn deficiency in wheat (Triticum aestivum). Seven group F TabZIP genes and 14 ZIPs with homeologs were identified in hexaploid wheat. Promoter analysis revealed the presence of Zn-deficiency-response elements (ZDREs) in a number of the ZIPs. Functional complementation of the zrt1/zrt2 yeast mutant by TaZIP3, -6, -7, -9 and -13 supported an ability to transport Zn. Group F TabZIPs contain the group-defining cysteine-histidine-rich motifs, which are the predicted binding site of Zn in the Zn-deficiency response. Conservation of these motifs varied between the TabZIPs suggesting that individual TabZIPs may have specific roles in the wheat Zn-homeostatic network. Increased expression in response to low Zn levels was observed for several of the wheat ZIPs and bZIPs; this varied temporally and spatially suggesting specific functions in the response mechanism. The ability of the group F TabZIPs to bind to specific ZDREs in the promoters of TaZIPs indicates a conserved mechanism in monocots and dicots in responding to Zn deficiency. In support of this, TabZIPF1-7DL and TabZIPF4-7AL afforded a strong level of rescue to the Arabidopsis hypersensitive bzip19 bzip23 double mutant under Zn deficiency. These results provide a greater understanding of Zn-homeostatic mechanisms in wheat, demonstrating an expanded repertoire of group F bZIP transcription factors, adding to the complexity of Zn homeostasis.© 2017 The Authors The Plant Journal published by John Wiley & Sons Ltd and Society for Experimental Biology.

本文总结分析了农田土壤锌含量分布现状、锌对小麦籽粒营养品质的影响、小麦对锌的吸收积累特性以及小麦籽粒锌营养强化途径等。土壤中锌含量的分布特征与地形地貌、地质构造和生态环境等密切相关,部分小麦主产区的土壤中锌含量较低。锌是一种重要的微量元素,对小麦籽粒淀粉和蛋白质含量均有影响,一般被植物根系吸收后,在根部压力或蒸腾作用下被输送到地上部,或者被横向输送到韧皮部,由韧皮部进行向上或向下的运输,再被运输到各组织和器官中。小麦锌强化途径包括遗传改良育种、农艺改良和生物技术应用等。研究结果为小麦富锌育种提供了一些新的思路。

【目的】明确施锌肥引起的土壤有效锌、小麦产量和籽粒锌含量的变化，为优化小麦锌营养强化技术提供重要依据。【方法】基于2017年在黄土高原旱地石灰性土壤上开始的定位试验，于2020—2021年和2021—2022年两个小麦生长期取样，研究锌肥用量对土壤有效锌、小麦产量、产量构成、籽粒及其不同部位锌吸收分配的影响。【结果】施用锌肥对小麦产量及产量构成要素无显著影响，但籽粒锌含量提高28.8%—46.0%，在施锌24.9 kg·hm^-2时，籽粒锌含量最高达31.1 mg·kg^-1；麸皮和面粉锌含量分别提高31.8%—58.8%、26.3%—41.3%，施锌27.3 kg·hm^-2时，麸皮锌含量最高，达87.6 mg·kg^-1；施锌24.0 kg·hm^-2时，面粉锌含量最高，达11.3 mg·kg^-1。在籽粒中，锌主要分配在麸皮，占77.7%—80.0%，平均锌含量78.9 mg·kg^-1；面粉占20.0%—22.3%，平均锌含量10.8 mg·kg^-1。施锌提高了麸皮和面粉的锌含量，麸皮锌含量增幅高于面粉。0—20和20—40 cm土层土壤有效锌含量分别提高235.2%—1233.8%和207.4%—825.9%，在最高施锌量27.3 kg·hm^-2时，土壤有效锌含量分别达9.47和2.50 mg·kg^-1。0—100 cm不同土层有效锌对小麦锌吸收的贡献存在差异，表层土壤对籽粒锌含量提高的作用显著高于深层土壤。【结论】在黄土高原旱地石灰性土壤上，施锌肥显著提高土壤有效锌含量和小麦籽粒锌含量；进一步改善小麦籽粒锌营养，应将锌肥用量、施锌方式和多种农艺措施，如水分和氮磷肥供应、绿肥种植等综合优化，充分挖掘旱地小麦籽粒锌含量提升的潜力。