施氮对不同品种冬小麦氮素累积和运转的影响

在鄂北岗地以当地主栽的5个冬小麦品种‘鄂麦14'、‘鄂麦18'、‘鄂麦23'、‘郑麦9023'、和‘洛麦1号'为试验材料,通过田间裂区试验在不施氮(0 kg/hm2)和施氮(195 kg/hm2)条件下研究不同品种小麦氮素的累积、转移与分配规律的差异.结果表明:(1)在扬花期,不施氮处理叶片、茎鞘和穗部氮素累积量均为‘鄂麦14' 最大,积累量分别达到14.2 、16.6 和10.8 kg/hm2;施氮后‘鄂麦23' 的叶片氮素积累量最大(71.5 kg/hm2),‘鄂麦14' 的茎鞘积累量最大(69.0 kg/hm2),‘鄂麦18'的穗部积累量最大(34.2 kg/hm2).(2)成熟后不同部位氮素转移效率表现为叶片>穗>茎鞘,且叶、茎鞘、穗氮素转移效率存在品种差异;不同品种间氮肥效率差异显著,并以‘鄂麦23'的氮肥利用率、氮肥农学效率最高,而‘郑麦9023'的氮肥生理效率最高.(3)在氮胁迫条件下,扬花前‘鄂麦14'各器官氮素累积量、成熟期的氮素转移率及籽粒氮素累积量都显著高于其它品种;而在施氮条件下,冬小麦各器官氮素的累积、转移与分配因品种不同而异,‘鄂麦14'和‘鄂麦23'籽粒及植株氮素累积量都显著高于其它品种.研究发现,冬小麦氮素的累积、转移与分配受品种与氮素调控共同影响;施氮能显著提高各器官氮素的累积量,且提高的幅度因品种而异.     

氮素营养水平对冬小麦碳氮运转的影响

在大田试验条件下,研究了不同施氮水平对2种穗型冬小麦品种花后干物质和氮素积累与运转的影响及其与产量和品质的关系,以探讨氮素营养水平对冬小麦碳氮运转的影响.结果显示,适宜的施氮量（180 kg·hm^-2）能够极显著增加2种穗型冬小麦品种叶片、茎鞘等营养器官花前贮藏物质及花前贮藏氮素的再运转量和运转率以及总再运转量和运转率,也能够极显著增加成熟期籽粒氮素含量和花前贮藏氮素总运转量对籽粒氮素含量的贡献率.各施氮处理对2种穗型小麦品种花后氮素积累量对籽粒氮素含量贡献率的影响效应不明显.结果表明,适宜的施氮量有利于小麦籽粒和蛋白质产量的提高.     

硫素对冬小麦旗叶抗坏血酸-谷胱甘肽循环系统的影响

选用大穂型品种'兰考矮早8'和多穂型品种'豫麦49-198'为供试材料,设置3个施硫水平,通过遮雨棚中盆栽试验研究了不同施硫量对冬小麦旗叶中抗坏血酸-谷胱甘肽抗氧化循环系统的影响.结果表明: 2个小麦品种抗坏血酸-谷胱甘肽抗氧化循环系统测定指标变化趋势表现一致,其中在花后28 d旗叶抗坏血酸(AsA)含量和谷胱甘肽硫转移酶(GSTs)表现有明显差异,但均表现为施硫处理高于对照,且达显著水平.2个品种花后旗叶中谷胱甘肽(GSH)含量、GSTs活性和抗坏血酸过氧化物酶(APX)活性变化均呈单峰曲线,在花后7～10 d达到高峰,后缓慢下降;AsA含量随生育进程推进逐步升高,至花后28 d达到高峰;花后旗叶中谷胱甘肽还原酶(GR)活性则随花后天数增加呈下降趋势.由此证明,施硫对小麦生育后期植株体内抗坏血酸-谷胱甘肽抗氧化循环系统有加强作用.     

氮、硫配施对弱筋小麦籽粒淀粉特性的影响

在大田条件下研究了不同氮、硫配施对弱筋小麦品种豫麦50籽粒淀粉特性的影响.结果表明:氮、硫及其互作对籽粒淀粉组分含量和直支比的影响均达到了极显著水平,氮肥对峰值粘度、低谷粘度、最终粘度和稀懈值的影响也达到了极显著水平,硫肥仅对稀懈值和糊化温度的影响达到了显著和极显著水平.每公顷施纯氮240 kg(N240)和纯硫20~60 kg(S20和S60)可提高总淀粉和支链淀粉含量,降低直链淀粉含量和直支比.每公顷施纯氮150 kg(N150)和纯硫20 kg(S20)可以提高峰值粘度、低谷粘度和最终粘度,改善淀粉品质.     

Interactive Effects of Sulphur Dioxide and Mineral Nutrient Supply on Photosynthetic Characteristics and Yield in Four Wheat Cultivars

Field experiments were conducted on four cultivars of wheat (Triticum aestivum L.) to examine the variability in cultivar response to sulphur dioxide (SO₂) under different concentrations of mineral nutrients. Thirty-days-old plants were exposed for 8 weeks to 390±20 µg m^–3 (0.15 ppm) SO₂ for 4 h per day, 5 d per week. Decline in net photosynthetic rate, contents of pigments and nitrogen, biomass and grain yield of each cultivars were due to SO₂ at all the nutrient concentrations studied. However, the magnitude of reduction was higher in plants grown without nutrient application. On the basis of the reductions in photosynthesis and yield, the susceptibility of wheat cultivars to SO₂ was in the order of Malviya 213 > Malviya 37 > Malviya 206 > Malviya 234 at recommended dose of NPK, whereas the same without the nutrients was Malviya 206 > Malviya 234 > Malviya 213 > Malviya 37.     

Effects of Nitrogen Fertilizer on Growth and Yield of Spring Wheat

Nine amounts of nitrogen fertilizer, ranging from 0 to 200 kgN ha^–1, were applied to spring wheat cv. Kleiber in the3 years 1972-1974. In 1972 grain dry weight with 125 kg N ha^–1or more was 100 g m^–2 (23 per cent) greater than withoutnitrogen. Grain yield was unaffected by nitrogen in the otheryears. Leaf area at and after anthesis was increased throughoutthe range of nitrogen tested, most in 1972 and least in 1973.Consequently, the addition of 200 kg N ha^–1 decreasedthe amount of grain produced per unit of leaf area by approximately25 per cent in all years. The dry weight of leaves and stems at anthesis and maturitywas increased by nitrogen in all years, similarly to leaf area.However, the change in stem dry weight between anthesis andmaturity was not affected by nitrogen; stems increased in dryweight for about 20 days after anthesis and then decreased tovalues similar to those at anthesis. The uptake of CO₂ per unit area of flag leaf or second leaf(leaf below the flag leaf) was slightly decreased by nitrogenwhen the increase in leaf area caused by nitrogen appreciablydecreased the light intensity at the surface of these leaves.In spite of such decreases the CO₂ absorbed by flag and secondleaves per unit area of land was always increased by nitrogen,and relatively more than was grain yield. It is suggested that increases in respiratory loss of CO₂ withincreasing nitrogen fertilizer may explain why nitrogen increasedvegetative growth and leaf area relatively more than grain yield.     

稀土元囊对小麦幼苗氮素吸收及同化的影响

稀土元素浸种能够促进小麦(Triticum aestivum L.)幼苗对No3-的吸收,提高硝酸还原酶活力。这些效应与稀土浓度有关,低浓度有促进作用,高浓度则有抑制作用。稀土元素处理还能促进小麦幼苗体内No3-的同化还原,使硝态氮含量降低,氨基氮含量增加,促进了氮素代谢过程。     

氮肥对杂交小麦组织氮转运及其杂种优势的影响

研究了施氮和不施氮条件下6个杂交小麦及其7个亲本不同器官的氮转运,结果表明:施氮时叶中的氮转运受到极显著的促进,其氮转运量为不施氮的4倍,总麦草90%以上的氮转运来自叶片;无论施氮与否,叶中氮的转运率和贡献率最大,穗壳次之,施氮与否的同一器官并无显著差异;不施氮的各器官氮的转运量、转运率和贡献率多表现正的杂种优势,施氮的多呈负向优势.     

氮肥和6-BA对花后受渍冬小麦抗渍性的调控效应

渍水是黄淮南部麦区和长江中下游麦区冬小麦生育后期的主要气象灾害因子,试验以小麦品种‘烟农19’为材料,采用裂区设计研究氮肥和6-BA对花后受渍冬小麦抗渍性的调控效应。结果显示:(1)花后渍害显著降低冬小麦根系活力、总吸收面积、活跃吸收面积、旗叶叶绿素含量、旗叶净光合速率,极显著降低穗粒数、千粒重和籽粒产量,而对穗数无显著影响。(2)受渍后叶面喷施氮肥+6-BA、氮肥、6-BA均能显著提高冬小麦花后抗渍性,其根系活力分别提高18.7%、14.6%、12.0%,根系总吸收面积分别提高31.9%、22.1%、19.6%,根系活跃吸收面积分别提高32.5%、21.7%、18.1%,叶绿素含量分别提高16.2%、9.4%、10.3%,净光合速率分别提高32.6%、23.3%、23.3%,穗粒数分别提高13.8%、9.3%、8.5%,千粒重分别提高17.3%、11.5%、10.5%,籽粒产量分别提高35.9%、23.5%、20.9%。研究表明,氮肥和6-BA正交互作用显著,即花后同时喷施氮肥和6-BA缓解小麦渍害的效果更佳。     

Nitrogen Translocation in Wheat Plants Under Soil Water Deficit

Accumulation and translocation of nitrogen (N) in the vegetative organs and grains of winter wheat (Triticum aestivum L.) are important processes in determining yield and quality. The present study was conducted to compare the effects of water deficit and cultivars (cv. Lumai 21 and Jinan 17) on N translocation from vegetative organs to grains in a mobile rain-shelter using ¹⁵N-labeled ammonium sulfate fertilizer. The N translocation amounts (defined as the difference between the N amount at anthesis and the N amount at maturity for a vegetative organ) in leaves were greatest for the two cultivars, followed by glumes, stems, and sheaths, respectively. The N translocation ratio (defined as the ratio of the translocation amount to N amount at anthesis) in total above-ground parts were greater for Lumai 21 (0.65 g g⁻¹ DW) than for Jinan 17 (0.60 g g⁻¹ DW), and Lumai 21 plants had a higher N translocation ratio for the N derived from fertilizers. The N contribution (defined as the ratio of the translocation amount to grain N amount) of total vegetative parts aboveground to grain N ranged from 0.50 to 0.77 g g⁻¹ DW, and that of the leaf was the greatest. The results showed that water deficit remarkably increased the N translocation ratio derived from soil and the contributions of N in various vegetative organs to grain N. It is suggested that water deficit would weaken the availability of fertilizer N but enhance the remobilization of prestored N to the grains.     

氮肥运筹对不同种植方式冬小麦群体结构及产量的影响

以山西农业大学培育的多穗型冬小麦山农9801为供试材料,采用随机区组的方法,在施氮总量每公顷300 kg时,分别对常规条播(B1)和窄行稀条播(B2)实施不同氮肥基追比:CK(10∶0)、C1(7∶3)、C2(5∶5)、C3(3∶7),研究其对拔节期小麦群体形态、各生育期叶面积指数及总茎数、产量构成因素的影响。结果表明:窄行稀条播促进了冬小麦群体生长,提高了实际产量。不同氮肥运筹对两种播种方式小麦生长及产量的影响很大,拔节期追施氮肥后小麦各指标均在C1、C2较高,整体看C1最高,且对窄行条播的提高作用更为明显。B2种植基追比7∶3时,旗叶面积、株高、次生根数最多,黄叶数最少,且与其他处理达到显著差异,拔节期到孕穗期LAI最高,群体总茎数及单株成穗数最大,C1处理通过显著增加有效穗数、穗粒数及千粒重来增加实际产量。上述分析结果为晋中窄行条播冬小麦氮肥合理利用,优质高产提供了实验和理论依据。     

Interactions Between Exogenous Cytokinin and Nitrogen Application Regulate Tiller Bud Growth via Sucrose and Nitrogen Allocation in Winter Wheat

Journal of Plant Growth Regulation - In this study, we assessed the effects of exogenous cytokinin and nitrogen levels on sucrose and nitrogen allocation and tiller bud growth. Results showed that...     

The Effects of Sulphur Dioxide on Phloem Transport in Two Cereals

Gould, R. P., Minchin, P. E. H. and Young, P. C. 1988. The effectsof sulphur dioxide on phloem transport in two cereals.—J.exp. BoL 39: 997–1007. In vivo investigations using ¹¹C-labelled photosynthate revealedthat there is a change in the patterns of tracer profiles whencereal leaves are exposed to SO₂. The change after exposureto SO₂ was interpreted in terms of a decrease in lateral waterflow into the sieve tubes brought about by reduced phloem loadingalong the length of a leaf. Analysis also revealed that thespeed of translocation was reduced, as expected by the Munchmodel of phloem transport. Key words: Sulphur dioxide, phloem transport, cereal leaves     

Translocation from the Flag Leaf of Winter Wheat in the Field

Translocation of assimilate from the flag leaf of winter wheat(Triticum aestivum cv. Maris Huntsman) was studied in the fieldby monitoring the export of photo-assimilated [^l4C]carbon dioxidewith a Geiger-Miiller counter placed under the fed area of leaf.The resulting export curve was analysed as a sum of two exponentialterms, and interpreted as a two-pool compartmental system. Therate constant for export from the leaf increased slightly frommaximum elongation to anthesis, then declined to almost halfits peak value just before the leaf lost all visible chlorophyll.The inter-pool transfer rate constants did not change significantlyover the same period, but all rate constants varied with timeof day. Short-term changes in the environment of the flag leaf had nodiscernible influence on translocation in the field. The timeconstants of the two pools of assimilate agreed with those forother species reported in the literature. These results areconsistent with the suggestion that sucrose is stored in thevacuole of mesophyll cells. The variations in rate constants with time of day, and deviationsof the export data from the two-pool model, suggest that exportand inter-pool transport have saturation kinetics. A model withMichaelis-Menten kinetics was formulated, and simulations ofthis model showed similar deviations from a simple two-poolsystem to those seen in our data.     

施硫对'豫麦50'籽粒灌浆特性及产量的影响

选用弱筋小麦品种‘豫麦50’为材料,通过大田试验研究了较高供氮水平下（施纯氮330kg／hm^2）施用低量（S20kg／hm^2）、中量（S60kg／hm^2）和高量（S100kg／hm^2）硫肥对小麦籽粒灌浆特性和产量的影响。结果显示,不同施硫处理的小麦籽粒灌浆进程均呈“慢-快-慢”的S型曲线,拟合的Logistic方程决定系数均大于0．9932,并达到极显著水平;灌浆持续期（T）、渐增期平均灌浆速率（V1）,快增期和缓增期持续期（T2、T3）、灌浆期各阶段干物质积累量（m1、m2、m3）和理论最大千粒重（K）均随施硫量增加而提高,并以中硫处理的各项灌浆参数表现较优;中硫处理的千粒重（46．47g）和籽粒产量（7416．0kg／hm^2）显著高于低硫处理,极显著高于对照（不施硫）和高硫处理。表明在当前较高施氮水平下,每公顷施纯硫60kg可有效改善小麦灌浆特性,显著提高籽粒产量。     

施硫对‘豫麦50’籽粒灌浆特性及产量的影响

选用弱筋小麦品种‘豫麦50’为材料,通过大田试验研究了较高供氮水平下(施纯氮330 kg/hm2)施用低量(S 20 kg/hm2)、中量(S 60 kg/hm2)和高量(S 100 kg/hm2)硫肥对小麦籽粒灌浆特性和产量的影响.结果显示,不同施硫处理的小麦籽粒灌浆进程均“呈慢—快—慢”的S型曲线,拟合的Logistic方程决定系数均大于0.993 2,并达到极显著水平;灌浆持续期(T)、渐增期平均灌浆速率(V1),快增期和缓增期持续期(T2、T3)、灌浆期各阶段干物质积累量(m1、m2、m3)和理论最大千粒重(K)均随施硫量增加而提高,并以中硫处理的各项灌浆参数表现较优;中硫处理的千粒重(46.47 g)和籽粒产量(7 416.0 kg/hm2)显著高于低硫处理,极显著高于对照(不施硫)和高硫处理.表明在当前较高施氮水平下,每公顷施纯硫60 kg可有效改善小麦灌浆特性,显著提高籽粒产量.     

Grain Growth Dynamics in Winter Wheat Crops

A procedure for analysing the dynamics of grain growth is developedand applied to data from winter wheat crops. The algorithm estimatesgrowth rate in relation to local data and preserves a shapethrough the whole growth curve by optimization subject to physiologically-justifiedconstraints: that grain growth rate decreases monotonically,and that there is a discontinuity to zero rate at physiologicalmaturity. It is assumed that effects of temperature can be allowedfor by expressing growth in relation to thermal time, accumulatedtemperature above a base temperature. Conditions are derivedunder which an optimal base temperature for grain growth rateexists under these physiological constraints. When applied todata from crops with different sowing dates and nitrogen treatmentsin different years, weak optimal base temperatures of 2.0 and7.5 °C were obtained for growth rate and duration, respectively.Initial growth rates were similar for all crops, but there wereconsiderable variations in rate later in grain growth. Thesevariations were, in part, related to the overall crop growthrate divided by the number of grains. Grain growth, modelling, winter wheat     

Suppression of Plant Growth by Nitrogen Dioxide

Nicotiana glutinosa and pinto bean seedlings (Phaseolus vulgaris) were exposed for short periods (3 days or less) to high concentrations of NO₂ (4.11-20.53 mg/m³ to compare the resulting leaf lesions with ozone damage produced at concentrations of 0.43 to 0.86 mg/m³. Although the same physiological age leaf tissue was damaged by both toxicants, damage caused by NO₂ was unlike that caused by ozone.

Pinto bean (Phaseolus vulgaris) and Pearson improved tomato (Lycopersicon esculentum) seedlings were continuously exposed for 10 to 22 days, to low concentrations of NO₂ (less than 1.03 mg/m³). These exposures caused significant growth suppression, increase in green color (total chlorophyll content), and distortion of leaves.

     

Influence of Nitrogen Supply on Uptake and Translocation of Strontium and Calcium in Wheat Seedlings

Supplying nitrate to N-depleted wheat seedlings (Triticum vulgare cv. Knox) stimulated the uptake and translocation of both ⁸³Sr and ⁴⁵Ca. Since the increase in ⁴⁵Ca accumulation was greater, the ⁸⁵Sr/⁴⁵Ca ratio in the plant tissue was decreased. Nitrate had relatively little influence on the amount of the divalent cations and ⁸⁵Sr/⁴⁵Ca ratio in the exchangeable fraction on the root surfaces, whereas it greatly increased the uptake into root tissue and translocation to shoots. The increase in percent transported to shoots occurred largely in the period of most rapid nitrate uptake. A split root study indicated that nitrate was ineffective when it was supplied to a different portion of the root system than that exposed to ⁸⁵Sr and ⁴⁵Ca. Nevertheless, ammonium and urea also increased the translocation of the two cations, indicating that the effects of nitrate could not entirely be ascribed to a direct effect of the nitrate anion.     

玉米秸秆还田和耕作方式对小麦养分积累与转运的影响

以冬小麦品种‘烟农19’为材料,于2008～2009年在淮北砂姜黑土区,设置玉米秸秆不还田(CK)和玉米秸秆全量粉碎还田——翻埋还田(HM)、旋耕还田(HX)、覆盖还田(HG)4种处理方式,通过大田试验研究玉米秸秆全量还田和耕作方式对小麦干物质和氮、磷、钾积累与分配的影响。结果显示:(1)小麦成熟期籽粒是干物质和养分的主要积累器官,其次为茎秆和叶片;在成熟期,籽粒积累的干物质、氮、磷、钾素分别占地上部总积累量的43.31%～46.13%、75.14%～76.83%、75.79%～77.99%、12.37%～12.82%。营养器官花前贮藏干物质和养分的转运量以叶片最高,其次为茎秆和颖壳;营养器官转运干物质和氮、磷、钾素对籽粒的贡献率分别为30.40%～36.54%、81.86%～86.10%、65.34%～74.83%、98.91%～125.85%。(2)玉米秸秆全量粉碎还田处理的小麦干物质和养分积累量与营养器官转运量均显著高于玉米秸秆不还田处理;玉米秸秆还田后不同耕作方式中,玉米秸秆全量覆盖还田处理的小麦籽粒干物质积累量和营养器官干物质转运量显著高于其它耕作方式,但氮、磷、钾的积累量和转运量在各耕作方式间差异均不显著。研究表明,在本试验条件下,在砂姜黑土区玉米秸秆全量粉碎覆盖还田处理更有利于小麦群体养分的积累与转运。