Forage and Food Legumes in a Multi‐Year,Wheat‐Based Rotation Under Drought‐Stressed Conditions in Northern Syria’s Medium Rainfall Zone

Long‐term crop rotation trials were designed to assess sustainability of alternatives to traditional fallow and monocropping. The trial described here (6 years) involved wheat (Triticum aestivum L.) in rotation with lentil (Lens culinaris L.), forage vetch (Vicia sativa), pasture medic (Medicago spp.), fallow and watermelon (Citrullus vulgaris). Barley (Hordeum vulgare L.) was compared with wheat for an additional 2 years. Cereal grain and straw yields were highest with fallow and watermelon followed by vetch, lentil and medic; the latter showed no differential effect of variable grazing intensity. Fertilizer N increased yields except in the low‐rainfall years (less than 250 mm). Barley out‐yielded wheat in terms of grain, but not straw. Medic yielded highest in dry matter, whereas lentil produced highest seed yield. Despite the difficulty of assessing crop and animal‐oriented rotations because of non‐commonality of outputs, economic considerations are foremost, but other benefits of rotations (soil quality, water‐use relations) are also relevant to the overall assessment of cereal‐based Mediterranean rotations. The study suggested barley rather than wheat as the desired cereal in rotation with legumes in this marginal‐rainfall (350 mm) environment and provided support for the viability of vetch and lentil in the cropping system. Given the importance of sheep in the region’s farming system, vetch is likely to have a major role in crop rotations.     

Dynamic change of mineral nutrient content in different plant organs during the grain filling stage in maize grown under contrasting nitrogen supply

The introduction of new hybrids and integrated crop-soil management has been causing maize grain yield to increase. However, less attention has been paid on the nutrient concentration of the grain; this aspect is of great importance to supplying calories and nutrients in the diets of both humans and animals worldwide. Increasing the retranslocation of nutrients from vegetative organs to grain can effectively increase the nutrient concentration of grain and general nutrient use efficiency. The present study involved monitoring the dynamic change of macro- and micronutrients in different organs of maize during the grain filling stage. In addition, the mobility of different elements and their contribution to grain nutrient content were evaluated in a 2-year experiment under low (LN, no N supplied) and high N (HN, 180 kg N ha⁻¹) supply. Under HN supply, the net remobilization efficiency (RE) of the vegetative organs as a whole (calculated as nutrient remobilization amount divided by nutrient content at silking) of N, P, K, Mn, and Zn were 44%, 60%, 13%, 15%, and 25%, respectively. The other nutrients (Mg, Ca, Fe, Cu, and B) showed a net accumulation in the vegetative organs as a whole during the grain filling stage. Among the different organs, N, P, and Zn were remobilized more from the leaves (RE of 44%, 51% and 43%, respectively) and the stalks (including leaf sheaths and tassels) (RE of 48%, 71% and 43%, respectively). K was mainly remobilized from the leaves with RE of 51%. Mg, Ca, Fe, Mn, and Cu were mostly remobilized from the stalks with the RE of 23%, 9%, 10%, 42%, and 28%, respectively. However, most of the remobilized Mg, Ca, Fe, Mn, Cu, and Zn were translocated to the husk and cob, which seemingly served as the buffer sink for these nutrients. The REs of all the nutrients except for P, K, and Zn were vulnerable to variations in conditions annually and were reduced when the grain yield and harvest index were lower in 2014 compared with 2013. Under LN stress, the RE was reduced in P and Zn in 2013, increased in Cu and unchanged in other nutrients. The concentration of these nutrients in the grain was either unchanged (P, K, Ca, Zn, and B) or decreased (N, Mg, Fe, Mn, and Cu). It is concluded that grain N, P, K, Mn, and Zn, but not Mg, Ca, Fe, Cu, and B concentration, can be improved by increasing their remobilization from vegetative organs. However, enhancing the senescence of maize plant via LN stress seems unable to increase grain mineral nutrient concentration. Genetic improvement aiming to increase nutrient remobilization should take into account the organ-specific remobilization pattern of the target nutrient.     

Sortentypische Unterschiede der Nährelementkonzentrationen bei Winterweizen

Genotypical Differences in the Nutrient Uptake of Winter Wheat
In order to investigate genotypical differences in the nutrient uptake of winter wheat cultivars the nutrient content of young wheat plants grown during 1982–1984 on three Brown Earth sites of Schleswig-Holstein were analysed.
Significant differences between the cultivars could be found in the content of the plants at shooting stage in P, K, Ca, Fe, Mn and Zn. The maximal difference between highest and lowest content (mean of 3 years) was about 20 % for P, K, Ca, Mn and Zn and 40 % for Mn. Since at shooting stage the dry matter production of the cultivars was about the same, the measured differences in nutrient concentrations may also represent differences in nutrient uptake.
Due to the low Mn-supply of the test soils the cultivars with the lowest Mn-uptake also produced the lowest grain yield.
By use of discriminant analysis it could be shown that the cultivars displayed a typical pattern of the nutrient concentrations. In the whole population two general types in nutrient pattern were found which are different in their concentrations of P, K, Ca and Zn.     

Accumulation,partitioning, and bioavailability of micronutrients in summer maize as affected by phosphorus supply

Decreased micronutrient concentration in cereal grains caused by excessive application of phosphorus (P) fertilizer may contribute to reduce their nutritional quality. To help correct this problem in maize grain, a 3-year field experiment was conducted to determine how P application rate affects micronutrient partitioning in maize shoots and other plant organs and micronutrient bioavailability in grain. Phosphorus application significantly decreased shoot zinc (Zn) and copper (Cu) concentrations at all growth stages but had no effects on shoot iron (Fe) and manganese (Mn) concentrations. As the P application rate increased, shoot Zn and Cu contents decreased, and shoot Fe and Mn contents increased. The ratios of pre-anthesis to post-anthesis mineral contents were not affected by P application rate except Zn. P application increased the percentage of Zn that was allocated to grain and decreased the percentage that was allocated to other tissues, but had no effects on the allocation of other micronutrients among tissues. The bioavailability of Zn, Cu, Fe, and Mn in grain decreased as P application rate increased. Overall, taking account of grain yield and nutrients concentration, P fertilizer rates should range from 12.5 to 25.0 kg P ha⁻¹ under the local condition. It can be concluded that not only grain yields, but also nutritional quality, should be considered in assessing optimal P rates in maize.     

Ertragsbildung von getreidereichen Fruchtfolgen und Getreide-monokulturen in einem extensiven und intensiven Anbausystem

Yield formation in cereal-rich crop rotations and monocultures in an extensive and intensive crop-management system
In a long duration trial, conducted from 1979/80 to 1992 at TU-Munich's research station in Roggenstein, the performance of monocultures of winter wheat, winter barley and winter rye, as well as numerous cereal-crop rotations were compared in an extensive and intensive crop-management system. The results obtained can be summarized as follows.
Over the course of 13 years, the influence of the immediately preceding crop on the yield of the main crops was of much greater significance than the rotation as a whole. With winter wheat, no yield differences could be observed between monoculture and cereal crop rotation (if the rotation did not include oats). Oats, rape, field bean, pea, potato and maize as preceding crops, however, in crop management systems, led to, on average, an increase in yield of 13 dt/ha from the following wheat. Winter barley yields were not significantly different in monoculture, cereal crop rotations and crop rotations containing 66% cereals. Furthermore, winter rye yields were the same in monocultures and cereal crop rotations. With all cereals, intensification of fertilizing and chemical plant protection led to a considerable increase in yield, but did not diminish the effects of the preceding crop. Hence, even with the use of modern agronomical techniques it is impossible to compensate for yield losses due to crop rotation.     

The Influence of Crop Rotation with an Increasing Content of Cereals on Photosynthetic Potential of Winter Wheat

In years 1982–1985 flag leaf area, concentration of chlorophyll and macronutrients (N, P, K, Ca, Mg, Na) and also their correlations to grain yield in static field experiment were studied. The main experimental plots comprised crop rotations containing 50, 75, 100% cereals. Treatments with or without irrigation were subplots and nitrogen levels (0, 60, 120, 180 kg N/ha) were sub-sub-plots.
The cultivation of winter wheat in rotations containing more than 50% cereals affected the drop of winter wheat grain yield, which was especially high on the plots without nitrogen fertilization or with low N level. The dose of 120 kg N/ha gave the highest grain yield in each rotation and, at the same time, decreased to minimum the differences between them, although wheat grown in the full cereal rotation yielded much less. The response of wheat grain yield to previous crop was affected by photosynthetic potential of a plant, which was constituated by flag leaf area and concentration of chlorophyll. The deteriorating nutrient economy in wheat plants grown in rotations containing more than 50% cereals decreased the photosynthetic potential of wheat. In addition, in these rotations the importance of macronutrients concentration in the flag leaf at anthesis as a source of nutrients for the developing grain is visible.     

源库调节对小麦不同品种籽粒微量元素及蛋白质含量的影响

为了解小麦籽粒微量营养元素含量的调控机制及其与籽粒重和蛋白质含量的关系, 以9个冬小麦品种为材料, 通过开花后减源(去叶、穗遮光)、减库(去50%小穗)处理, 分析了成熟籽粒中Fe、Zn、Mn、Cu等微量元素含量与籽粒重、蛋白质含量变化及其相互关系, 并探讨了籽粒微营养素积累的源库调控作用。结果表明, 籽粒中Fe、Zn、Mn、Cu、蛋白质含量和籽粒重均在品种间和源库处理间存在显著差异。去叶源不仅使籽粒重和籽粒蛋白质含量显著降低, 而且使籽粒Fe、Zn、Mn和Cu含量明显降低; 穗遮光使籽粒重显著降低, 蛋白质含量略有提高, 籽粒微量元素含量的变化因品种和元素类型而异, 总体趋势为Fe、Zn和Cu含量增加, Mn含量降低; 去小穗减少库, 使各品种剩余籽粒粒重略有增加, 而蛋白质含量提高, 籽粒Fe、Zn、Mn和Cu含量均较大幅度提高。籽粒Fe、Zn、Mn和Cu含量主要受各元素供源的限制, 不同元素受供源影响程度不同, 且与品种基因型有关。籽粒中4种微量元素含量之间及其与粒重和蛋白质含量之间具有一定的正相关性, 说明籽粒微量元素含量与籽粒重和蛋白质含量存在同步提高的可 能性。     

张掖地区土壤微量元素空间分布及其对农产品质量的影响

对张掖市甘州区、临泽县、高台县、民乐县、肃南县及农场耕层土壤进行取样分析,共测试分析789个土样的有效铁、有效锰、有效铜、有效锌和有效硼五项微量元素指标。对测试结果采用Normal-QQplot方法进行正态分布检验,剔除了14个异常离群值。对剩余的775个测试分析数据用地统计普通克里金插值法进行空间插值,根据各微量元素的空间分布和缺素临界值,把五种微量元素按照含量空间分布划分为丰富、持平和不足三个级别。并依据不同级别的肥力区和作物缺素症状,提出各肥力区对农产品质量的影响以及施肥方案,为张掖市作物微肥施用提供参考。     

Morphological and physiological differences in the response of cereals to zinc deficiency

Greenhouse and growth chamber experiments were carried out using seven bread wheat (Triticum aestivum), three durum wheat (T. durum), two rye (Secale cereale), three barley (Hordeum vulgare), two triticale (x Triticosecale Wittmack) and one oat (Avena sativa) cultivars to study response to zinc (Zn) deficiency and Zn fertilisation in nutrient solution and in a severely Zn deficient calcareous soil. Visual Zn deficiency symptoms, such as whitish-brown necrotic patches on leaf blades, developed rapidly and severely in the durum wheat and oat cultivars. Bread wheat showed great genotypic differences in sensitivity to Zn deficiency. In triticale and rye, visual deficiency symptoms were either absent or appeared only slightly, while barley showed a moderate sensitivity. When grown in soil, average decreases in shoot dry matter production due to Zn deficiency were 15% for rye, 25% for triticale, 34% for barley, 42% for bread wheat, 63% for oat and 65% for durum wheat. Differential Zn efficiency among and within cereal species was better related to the total amount of Zn per shoot, but not to the Zn concentration in the shoot dry matter. However, in leaves of Zn efficient rye and bread wheat cultivars, the activity of Zn-containing superoxide dismutase was greater than in Zn inefficient bread and durum wheat cultivars, suggesting higher amounts of physiologically active Zn in leaf tissue of efficient genotypes. When grown in nutrient solution, there was a poor relationship between Zn efficiency and release rate of Zn-chelating phytosiderophores from roots, but uptake of labelled Zn (⁶⁵Zn) and its translocation to the shoot was higher in the Zn efficient rye and bread wheat cultivars than in inefficient bread and durum wheat cultivars. The results demonstrate that susceptibility of cereals to Zn deficiency decline in the order durum wheat > oat > bread wheat > barley > triticale > rye. The results also show that expression of high Zn efficiency in cereals was causally related to enhanced capability of genotypes to take up Zn from soils and use it efficiently in tissues. This revised version was published online in August 2006 with corrections to the Cover Date.     

Relay-intercropped forage legumes help to control weeds in organic grain production

In organic grain production, weeds are one of the major limiting factors along with crop nitrogen deficiency. Relay intercropping of forage legume cover crops in an established winter cereal crop might be a viable option but is still not well documented, especially under organic conditions.Four species of forage legumes (Medicago lupulina, Medicago sativa, Trifolium pratense and Trifolium repens) were undersown in six organic wheat fields. The density and aerial dry matter of wheat, relay-intercropped legumes and weeds were monitored during wheat-legume relay intercropping and after wheat harvest until late autumn, before the ploughing of cover crops.Our results showed a large diversity of aerial growth of weeds depending on soil, climate and wheat development. The dynamics of the legume cover crops were highly different between species and cropping periods (during relay intercropping and after wheat harvest). For instance, T. repens was two times less developed than the other species during relay intercropping while obtaining the highest aerial dry matter in late autumn. During the relay intercropping period, forage legume cover crops were only efficient in controlling weed density in comparison with wheat sole crop. The control of the aerial dry matter of weeds at the end of the relay intercropping period was better explained considering both legumes and wheat biomasses instead of legumes alone. In late autumn, 24 weeks after wheat harvest, weed biomass was largely reduced by the cover crops. Weed density and biomass reductions were correlated with cover crop biomass at wheat harvest and in late autumn. The presence of a cover crop also exhibited another positive effect by decreasing the density of spring-germinating annual weeds during the relay intercropping period.     

黑龙江省不同类型土壤微量元素含量及对稻米品质的影响

采用单因素方法研究黑龙江省不同类型土壤铜、锰、铁、锌微量元素含量与稻米子粒铜、锰、铁、锌微量元素的关系及其对稻米品质的影响。结果表明,不同类型土壤铜含量顺序为白浆土>黑土>草甸土>盐碱土,锰和铁的含量顺序与铜一致,锌的含量则是黑土>白浆土>草甸土>盐碱土。土壤中的铜、锰、铁、锌含量与水稻子粒中各微量元素含量达极显著正相关;水稻子粒中铜、锰、铁、锌含量高,稻米整精米率、长宽比和食味评分降低,蛋白质含量和垩白粒率升高;各微量元素对于稻米出糙率和直链淀粉含量的影响不一致,子粒中铜、锰、铁含量高,稻米出糙率高,锌含量与稻米出糙率则相反,各微量元素对于稻米的出糙率影响不大,铜和锌含量低,锰和铁含量高,稻米的直链淀粉含量高,子粒中各微量元素与稻米品质指标的关系间接反映出各类土壤微量元素含量与稻米品质指标的关系。     

Quantitative trait loci for phytate in rice grain and their relationship with grain micronutrient content

Phytate (inositol-hexa-phosphate) has an important role in plants but it also may have anti-nutritional properties in animals and humans. While there is debate within the plant breeding and nutrition communities regarding an optimum level in grain, there appears to be little information at the molecular level for the genetics of this trait, and its association with important trace elements, in particular, Fe and Zn. In this preliminary study, quantitative trait loci (QTL) for grain phytates, Zn and Fe in glasshouse-grown rice lines from an IR64 × Azucena doubled haploid population were identified. Correlations between phytate and essential nutrients were also studied. Transgressive segregation was found for most traits. Phytate and total P concentrations had one QTL in common located on chromosome five with the (high concentration) allele contributed from Azucena. There were significant positive correlations between phytate and inorganic phosphorus (P), total P, Fe, Zn, Cu and Mn concentrations for both grain concentration and content. However, the QTLs of phytate were not located on the same chromosomal regions as those found for Fe, Zn and Mn, suggesting that they were genetically different and thus using molecular markers in breeding and selection would modify the phytate level without affecting grain micronutrient density.     

不同P-Zn配比对小麦幼苗微量元素营养的影响

采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.     

用激光剥蚀电感耦合等离子体质谱研究小麦籽粒元素的共分布

增加粮食可食用部分微量营养元素的浓度, 需要更好地了解其在植株, 特别是籽粒内的运输和分布规律。激光剥蚀电感耦合等离子体质谱(laser ablation inductively coupled plasma mass spectrometry, LA-ICP-MS)是一种测定植物组织中元素空间分布的新技术。采用该技术对成熟小麦籽粒中锰(Mn)、铜(Cu)、锌(Zn)和磷(P)的空间分布及其关联程度定量研究。结果表明, 所测元素在籽粒不同部位的浓度分布差异很大。Cu、Zn和P浓度均以糊粉层最高, 胚乳最低, 胚居中, 浓度最大差异分别达15、42和33倍; Mn浓度则以胚最高, 胚乳最低, 糊粉层居中, 浓度最大差异达9倍。籽粒同一部位不同位置的元素浓度亦不相同, 外周胚乳(靠近糊粉层)的元素浓度大于内侧胚乳部位对应元素的浓度, 胚最外侧盾片部位的元素浓度大于胚中间位置的元素浓度, 且各元素趋势一致。比较分析发现, 麦粒不同部位元素的浓度变化存在明显的同步性, 籽粒中P浓度高的部位金属元素(Mn、Cu和Zn)浓度也高。这说明不同元素在向籽粒不同部位运输和积累过程中可能存在密切关联性。     

几种复混微肥对苜蓿微量元素营养的影响

根据河南省牧草种植区土壤微量元素含量、牧草营养及动物营养的需求特点,利用铁、锰、铜、锌、硼、钼、钴等几种微肥进行组配,来研究其对紫花苜蓿（Medicago sativa L.）微量元素营养的影响,其目的为生产提供不同用途的富含微量元素的优质牧草。结果显示：CD组配能促进紫花苜蓿第二茬铁、锌、硼,第三茬铁、锌、硼、铜含量的显著增加;及除第二茬钴外的各茬元素积累量增加。C1D1组配能促进紫花苜蓿第一茬钼、钴、硼,第二茬锌、钼、钴、硼、铁,第三茬铜、锌、硼、铁、锰含量的显著增加;及除第二茬铁外的各茬元素积累量增加。C1D2组配能促进紫花苜蓿第一茬锌、钼、钴,第二茬锌、钼、钴、硼、铁、锰,第三茬锌、钴、硼、铁、锰含量显著增加;及除第二茬铁外的各茬元素积累量的增加。C2D1组配能促进紫花苜蓿第一茬锌、钼、钴,第二茬铜、锌、钼、钴、硼、铁、锰,第三茬钼、硼、铁含量显著增加;及除第二茬铁外的各茬元素积累量的增加。C2D2组配能促进紫花苜蓿第一茬铜、锌、钼、钴,第二茬锰、铜、锌、钼、钴、硼、铁,第三茬锰、锌、钼、钴、硼、铁含量显著增加;及各茬元素积累量的增加。     

Effects of planting soybean in summer fallow on wheat grain yield,total N and Zn in grain and available N and Zn in soil on the Loess Plateau of China

Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200 m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089 kg ha⁻¹ at the 108 kg N ha⁻¹ rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.     

小麦主要亲缘种籽粒的Fe、Zn、Cu、Mn含量及其聚类分析

以19份小麦亲缘种及普通小麦中国春为材料,测定比较了籽粒的Fe、Zn、Cu、Mn含量,并进行了聚类分析。结果表明,Fe、Zn、Cu、Mn含量平均值分别为50.94、34.89、6.96和33.21 μg g^-1,其改良潜力分别为121.94%、40.46%、41.17%和73.03%。根据Fe、Zn、Cu、Mn含量将供试材料均分为高、中、低3类,其中塔城高拉山小麦Fe含量高达124.32 μg g^-1,为富Fe材料。富Zn材料有野生一粒小麦、野生二粒小麦等6个品种（系）,均值为49.91 μg g^-1。富Cu材料有分枝小麦和小黑麦(8X),均值为8.66 μg g^-1。富Mn材料为斯卑尔脱小麦,含量高达63.85 μg g^-1。不同倍性染色体倍性材料间,Fe、Zn和Mn含量均以四倍体小麦最高,Cu含量以八倍体小麦最高。不同染色体组间,AABB染色体组材料的Fe、Zn和Mn含量最高,其次是AA染色体组材料,Cu以AABBDDRR染色体组最高。这些结果可为小麦营养品质育种的亲本选择和有利基因的发掘和利用提供参考依据。     

缺锌条件下小麦的养分吸收状况及不同基因型的耐性差异

采用螯合-缓冲营养液（Chelator-buffer culture solution）进行培养试验,对缺锌条件下3种小麦基因型（绵阳19、邯6172、新麦13）的生长发育状况及对P、Cu、Fe、Mn营养的影响进行了研究,并且应用4种指标,即锌效率（缺锌与锌充足供应条件下小麦地上部干物质之比）、相对冠根比（缺锌与锌充足供应条件下小麦冠根比之比）、缺锌条件下小麦地上部的锌吸收量、干物质量,对3种小麦的耐缺锌能力进行了比较。结果表明,在锌缺乏条件下小麦地上部生长量明显降低,而根系依然能保持相对较强的生长发育能力;不同小麦基因型对缺锌的耐性存在明显差异,其中邯6172的耐性最强;在缺锌胁迫条件下,小麦地上部Cu、Fe、Mn含量及Cu／Zn、Fe／Zn、Mn／Zn均明显升高,地上部锌含量与Cu、Fe、Mn含量均呈极显著负相关,说明锌缺乏能够促进Cu、Fe、Mn在地上部的累积。与此相反,锌缺乏条件下小麦P含量及吸收量均明显降低,地上部磷、锌含量之间极显著正相关,但与Cu,Fe,Mn相似,缺锌后P从根系向地上部的转运率升高。同时,对缺锌耐性最强的小麦基因型邯6172在锌缺乏条件下,地上部Cu、Fe、Mn含量的升高与P含量的降低幅度均是3种供试小麦中最大的,似乎表明小麦对锌缺乏的耐性大小与对Cu、Fe、Mn的吸收能力及与对P吸收的抑制有关。     

微量元素喷施对冬小麦籽粒产量和品质的影响

通过对不同生育期小麦叶面喷施不同浓度微量元素,探究冬小麦对微量元素的吸收和利用。采用大田试验,设置1倍(B1)、50倍(B2)、100倍(B3)和500倍(B4)四个浓度处理（等量水为对照）,喷施时期为苗期(A1)、苗期+拔节期(A2)、苗期+拔节期+扬花期(A3)、拔节期(A4)、拔节期+扬花期(A5)和扬花期(A6),测定成熟期产量及籽粒微量元素含量。不同处理下产量变化范围为3741~6204 kg/hm²,A4B4处理下产量最优,相对于对照产量增加了39.52%。锌(Zn)变化范围为31.07~44.68 mg/kg,A3B1处理下Zn含量最高。铜(Cu)变化范围为1.75~28.67 mg/kg,A1B1处理下Cu含量最高。铁(Fe)变化范围为73.62~203.99 mg/kg,A3B1处理下Fe含量最高。锰(Mn)变化范围为36.48~55.56 mg/kg,A6B4处理下Mn含量最高。相对于对照,Zn、Cu、Fe、Mn含量分别提高了37.86%、1650%、148%和26.82%。拔节期喷施高浓度微量元素对增产最有利,不同喷施时期和喷施浓度影响微量元素的利用效率。