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1.
不同品种油菜氮效率差异及其成因分析 总被引：4，自引：0，他引：4
采用盆栽试验，以氮胁迫与正常供氮条件下籽粒产量的比值作为氮效率系数，探讨了不同品种油菜氮效率差异及其生理基础。结果表明，所测定的8个油菜品种氮效率系数的变化范围是0．37～0．69；氮胁迫与正常供氮条件下不同油菜品种植株氮素累积吸收量、生长后期茎叶氮素转运率及氮素生理效率的比值不同，氮效率高的品种，其比值高，反之亦然;在氮素供应水平低的情况下，氮效率高的品种具有较长的根长、较多的侧根、较高的茎叶硝态氮再利用量和叶片硝酸还原酶活性。 相似文献
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不同品种油菜氮效率差异及其生理基础研究 总被引：12，自引：1，他引：11
采用盆栽土培试验,以氮胁迫与正常供氮条件下的子粒产量比值作为氮效率系数,探讨了不同品种油菜氮效率差异及其生理基础。结果表明,供试5个油菜品种的氮效率有显著差异,其氮效率系数的变化范围是0.37~0.69。在氮胁迫条件下,氮高效品种的植株含氮量与氮素累积吸收量、叶片叶绿素含量与硝酸还原酶活性、茎叶可溶性糖含量与硝态氮再利用量高于氮低效品种。在正常供氮条件下,高潜力品种的植株含氮量低于低潜力品种,但由于其生物量较高,氮素累积吸收量并不低于低潜力品种,甚至苗期的氮素累积吸收量高于低潜力品种;高潜力品种的叶片叶绿素含量与硝酸还原酶活性、茎叶可溶性糖含量与硝态氮再利用量高于低潜力品种。说明上述4种生理指标均可作为评价油菜氮效率及增长潜力差异的间接指标。 相似文献
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氮饥饿水稻利用不同形态氮素的差异及其生理机制 总被引：8，自引：0，他引：8
通过水培试验，研究了氮饥饿7d后，恢复供应不同形态氮源对水稻氮吸收和积累及氮同化中关键酶活性和光合色素的影响。结果表明，缺氮促进根系生长，增加根冠比。恢复供氮4d显著增加地上部生物量。铵硝混合营养促进了水稻对氮的吸收和转运，叶片和根系中全氮及叶片中铵态氮的含量以硝酸铵处理最高。与单一铵或硝营养相比，铵硝混合营养增强了根系的谷氨酰胺合成酶和叶片中硝酸还原酶的活性，提高了水稻同化和利用氮的能力。另外，与纯硝营养相比，供应铵态氮显著增加了叶片中总叶绿素，尤其是叶绿素a的含量。因此，改善水肥管理、平衡对水稻供氮的铵硝配比将提高水稻氮素的吸收和利用效率。 相似文献
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氮素对玉米幼苗生长、根系形态及氮素吸收利用效率的影响 总被引：28，自引：9，他引：19
采用水培试验,比较分析了氮素对高产玉米杂交种幼苗生长、根系形态及氮素吸收利用效率的影响。结果表明,在一定氮素范围内供氮量的增加能够促进玉米地上部的生长,也促进东单90（DD90）和沈玉21（SY21）根系干重的增加,而高量供氮会抑制根系的生长,导致根冠比下降。郑单958（ZD958）在8.0 mmol/L氮水平下地上部受抑制的程度大于根系,造成根冠比有所增加。在各氮素水平下,东单90具有很好的根系形态,提高了氮素的吸收能力,从而提高氮素积累量。随氮浓度的增加,玉米植株氮素吸收效率增大而氮素生理利用效率减小,无论在低氮还是高氮条件下,郑单958和东单90的氮素吸收效率均显著高于沈玉21和郝育12（HY12）,氮素生理利用效率却显著低于沈玉21和郝育12。不同品种对氮素的响应存在显著差异,东单90和郑单958耐低氮和对氮素吸收的能力强,郑单958耐高氮能力相对较弱,沈玉21和郝育12对氮素需求量大,耐低氮能力弱。适宜的氮素供应能更好地协调根系与地上部的关系,促进根系形态发育,增加根系对氮素的接触面积,促进根系对氮素的高效吸收。 相似文献
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6.
Christos Noulas Markus Liedgens Peter Stamp Ioannis Alexiou Juan M. Herrera 《Journal of plant nutrition》2013,36(13):1887-1903
In a two-year (1999–2000) field experiment four Swiss spring wheat (Triticum aestivum L.) genotypes (cvs. ‘Albis’, ‘Toronit’ and ‘Pizol’ and an experimental line ‘L94491’) were compared for genotypic differences in the root parameters that determine uptake potential and nitrogen use efficiency (NUE):root surface area (RSA) and its components, root length density (RLD) and the diameter of the roots. The genotypes were grown under no (N0) and under ample fertilizer nitrogen (N) [ammonium nitrate (NH4NO3); N1; 250 kg N ha?1] supply. Root samples were taken from all the genotypes at anthesis from the subsoil (30–60 cm). Genotypic effects on RLD and RSA were evident only in 2000 and large amounts of N fertilizer usually diminished root growth. Adequate soil moisture in 1999 may have favored the establishment of the root system of all the genotypes before anthesis. Parameters of NUE for each genotype were also determined at anthesis and at physiological maturity. ‘Albis’ the least efficient cv. in recovering fertilizer N (ranged from 36.5 to 61.1%) with the lowest N uptake efficiency (0.47 to 0.79 kg kg?1) had the lowest RLD and RSA in both seasons. Among genotypes ‘Toronit’, a high-yielding cv., efficient in recovering fertilizer N, exhibited the higher NUE (22.4 to 29.3 kg kg?1) and tended to have the highest values of RLD and RSA. Nitrogen fertilization also led to an increase in the proportion of roots with diameters less than 300 μm and decreased the proportion of roots with diameters of 300 to 700 μm. These trends were more pronounced for cv. ‘Pizol’ in 1999 and for cv. ‘Toronit’ in 1999 and 2000. By anthesis in a humid temperate climate, there are no marked differences in the subsoil root growth of the examined genotypes. Some peculiarities on the root growth characteristics of the cultivars ‘Albis’ and ‘Toronit’ may partially explain their different NUE performance. 相似文献
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施氮对"双低"油菜吸氮特性及氮素生理效率的影响 总被引：6，自引：1，他引：6
采用盆栽试验研究施氮对双低油菜吸氮特性及产量的影响。结果表明，植株氮素累积量，施氮处理从苗期到抽苔末期迅速增加，抽苔末期到开花末期下降，开花末期后有所回升，但仍没有超过抽苔末期的氮素累积量；不施氮处理与施氮处理有类似的变化趋势，但变化幅度明显小于施氮处理，而且开花末期后的氮素累积量超过了抽苔末期。无论施氮与否，营养器官含氮量随生育期的进程持续下降，而生殖器官含氮量施氮时持续下降，不施氮时则呈单峰曲线。干物质累积最大速率出现的日期，不施氮处理明显早于施氮处理。氮素生理效率，施氮处理在角果发育期最高，而不施氮处理在开花末期最高。施氮明显增加植株氮素累积量、植株含氮量、生物量及籽粒产量，但氮素生理效率却降低。 相似文献
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不同氮肥用量对蔬菜硝态氮累积的影响 总被引：126，自引：13，他引：113
利用盆栽试验,研究了氮肥用量对蔬菜硝态氮累积的影响。结果表明,施用氮肥使蔬菜的生长量提高1.1～6.1倍,但增长并不与氮肥用量同步。氮肥用量较高时,蔬菜生长受到抑制,生长量有降低趋势;硝态氮含量却随氮肥用量增加而不断升高,两者呈显著正相关（r=0.933～0.957）。蔬菜各器官、部位的硝态氮含量存在明显差异。不施氮肥时,根的硝态氮含量大于茎叶,茎又大于叶;施氮后根的含量小于茎叶,茎小于叶;无论施氮与否,叶柄的含量均高于叶片。把蔬菜的生长、硝态氮吸收及还原转化联系起来分析,可以看出,增加氮肥用量虽然提高了硝酸还原酶活性,但硝态氮的还原作用仍小于吸收,从而导致蔬菜体内出现硝态氮累积。而且,随氮肥用量增加,硝态氮累积量的增加远超过了生长量的提高,使硝态氮含量迅速升高。 相似文献
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油菜根系形态和生理特性与其氮效率的关系 总被引：6，自引：1，他引：5
为了给氮(N)高效油菜品种的选育及应用提供科学依据,采用土培实验对不同油菜品种在不同N素水平下各生育期的根系活力、根系吸收表面积、根系体积以及一级侧根数与N效率的关系进行了研究。结果表明:在油菜的整个生育期里,不同N素水平对油菜根系的形态及生理特性有显著的影响,均随着施N水平的增加而升高;正常施N条件下全生育期的一级侧根数,苗期的根系体积、吸收表面积与油菜N效率密切相关,而根系活力对N效率的影响相对较小;在不施N条件下全生育期的一级侧根数、根系活力,苗期以后的根系体积、吸收表面积与油菜N效率密切相关。 相似文献
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The effect of different levels and forms of nitrogen (N) fertilizer on cadmium (Cd) concentrations in potato (Solanum tuberosum L.) tubers, a large component of the northern European diet, was investigated with the aim of decreasing the Cd content. A high and a low Cd-accumulating cultivar were used in two field trials and a pot experiment. The N fertilizers tested were balanced N- phosphorus (P)- potassium (K) 11-5-18 + micronutrients, alkaline calcium nitrate and acidic ammonium sulfate at levels of 60, 160, and 240 kg N ha?1 at planting or (for the higher N doses) split between two or three occasions. The Cd concentration in tubers of both cultivars decreased when increasing the N fertilizer from 60 to 160 or 240 kg N ha?1, indicating that Cd uptake and translocation are not positively correlated to the growth rate of the potato plant. A strong positive linear correlation was found between the Cd concentration in leaves at 77 days after planting and the Cd concentration in tubers at harvest, irrespective of N treatment, although the Cd concentration was three-fold higher in the leaves. The genetic variation in leaf and tuber Cd accumulation was consistent, regardless of the form of N fertilizer used. Ammonium sulfate decreased soil pH and increased tuber Cd concentration in both cultivars compared with NPK fertilizer, possibly due to increased amounts of plant-available Cd arising from the pH decrease after ammonium sulfate application. The tuber Cd concentration in the low Cd-accumulating cultivar increased when fertilized with calcium nitrate, an effect attributed to Cd availability being influenced by the increased Ca2+ concentration. 相似文献
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Nitrate‐N uptake from soil depends on root growth and uptake activity. However, under field conditions N‐uptake activity is difficult to estimate from soil‐N depletion due to different loss pathways. We modified the current mesh‐bag method to estimate nitrate‐N‐uptake activity and root growth of two oilseed‐rape cultivars differing in N‐uptake efficiency. N‐efficient cultivar (cv.) ‘Apex' and N‐inefficient cv. ‘Capitol' were grown in a field experiment on a silty clayey gleyic fluvisol near Göttingen, northern Germany, and fertilized with 0 (N0) and 227 (N227) kg N ha–1. In February 2002, PVC tubes with a diameter of 50 mm were installed between plant rows at 0–0.3 and 0–0.6 m soil depth with an angle of 45°. At the beginning of shooting, beginning of flowering, and at seed filling, the PVC tubes were substituted by PVC tubes (compartments) of the same diameter, but with an open window at the upper side either at a soil depth of 0–0.3 or 0.3–0.6 m allowing roots to grow into the tubes. Anion‐exchange resin at the bottom of the compartment allowed estimation of nitrate leaching. The compartments were then filled with root‐free soil which was amended with or without 90 mg N (kg soil)–1. The newly developed roots and nitrate‐N depletion were estimated in the compartments after the installing period (21 d at shooting stage and 16 d both at flowering and grain‐filling stages). Nitrate‐N depletion was estimated from the difference between NO ‐N contents of compartments containing roots and control compartments (windows closed with a membrane) containing no roots. The amount of nitrate leached from the compartments was quantified from the resin and has been taken into consideration in the calculation of the N depletion. The amount of N depleted from the compartments significantly correlated with root‐length density. Suboptimal N application to the crop reduced total biomass and seed‐yield formation substantially (24% and 38% for ‘Apex’ and ‘Capitol’, respectively). At the shooting stage, there were no differences in root production and N depletion from the compartments by the two cultivars between N0 and N227. But at flowering and seed‐filling stages, higher root production and accordingly higher N depletion was observed at N0 compared to N227. Towards later growth stages, the newly developed roots were characterized by a reduction of root diameter and a shift towards the deeper soil layer (0.3–0.6m). At low but not at high N supply, the N‐efficient cv. ‘Apex’ exhibited higher root growth and accordingly depleted nitrate‐N more effectively than the N‐inefficient cv. ‘Capitol’, especially during the reproductive growth phase. The calculated nitrate‐N‐uptake rate per unit root length was maximal at flowering (for the low N supply) but showed no difference between the two cultivars. This indicated that the higher N‐uptake efficiency of cv. ‘Apex’ was due to higher root growth rather than higher uptake per unit of root length. 相似文献
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【目的】探究油菜NO3-的吸收、分配和对低氮胁迫的响应及其氮利用效率,为理解油菜在不同低氮胁迫下相关生理变化及其氮素利用效率提供科学依据。【方法】以常规油菜品种814为研究材料,采用砂培试验,在正常供氮水平（10 mmol/L）和低氮胁迫水平（3 mmol/L、1 mmol/L）下,研究油菜的根系特性、蒸腾作用对低氮胁迫的响应及其氮素吸收效率,并研究油菜NO3-的运输分配与同化对低氮胁迫的响应及其氮素利用效率。【结果】与正常供氮处理（10 mmol/L）相比,低氮胁迫处理（3 mmol/L、1 mmol/L）的油菜NO3-含量、全氮含量均显著下降,但（NO3-）叶/根、（全氮（%））叶/根显著升高,植株根系干物质重、根系吸收面积均显著下降,但根冠比显著升高。油菜植株在低氮胁迫下气孔导度和蒸腾速率显著增加,一方面促进植株对NO3-的捕获,另一方面也促使更大比例的NO3-分配在植物的地上部分,但植株的水分散失加剧,水分利用效率显著下降。低氮胁迫处理油菜根和叶中NR、GS活性与正常供氮处理之间的差异不显著或有增加,其叶绿素含量、光合速率均显著下降,但光合氮素利用率显著升高。【结论】在低氮胁迫条件下,油菜植株的氮素和干物质累积均显著下降,但NO3-在植株的地上部分分配比例的增加以及光合氮素利用率的升高促使植株的氮素利用效率显著提高。 相似文献
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Julie Gombert Frédérik Le Dily Jérémy Lothier Philippe Etienne Laurence Rossato Jean‐Michel Allirand Alexandra Jullien Alexandre Savin Alain Ourry 《植物养料与土壤学杂志》2010,173(6):875-884
In order to optimize nitrogen (N) fertilization and to reduce the environmental impact of oilseed rape without decreasing yield, a clearer understanding of N dynamics inside the plant is crucial. The present investigation therefore aimed to study the effects of different N‐application rates on the dynamics of N uptake, partitioning, and remobilization. The experiment was conducted on winter oilseed rape (Brassica napus L. cv. Capitol) under three levels of N input (0, 100, and 200 kg N ha–1) from stem elongation to maturity using 15N‐labeling technique to distinguish between N uptake and N retranslocation in the plant. Nitrogen fertilization affected the time‐course of N uptake and also the allocation of N taken up from flowering to maturity. Most pod N came from N remobilization, and leaves accounted for the largest source of remobilized N regardless the N‐application rate. However, the contribution of leaves to the remobilized N pool increased with the N dose whereas the one of taproot decreased. Stems were the main sink for remobilized N from stem elongation to flowering. Leaves remained longer on N200 than on N0 and N100 plants, and N concentration in fallen leaves increased with the N treatment and in N100 plants along an axial gradient from the basal to the upper leaves. Overall, these results show that the timing of N supply is more crucial than the N amount to attain a high N efficiency. 相似文献
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Christos Noulas Ioannis Alexiou Juan M. Herrera Peter Stamp 《Journal of plant nutrition》2013,36(8):1201-1218
Field experiments were conducted for two years to compare and identify bread spring wheat (Triticum aestivum L.) genotypes which make the most efficient use of nitrogen (N). Such information is required for breeding strategies to reverse the negative relationship between yield and protein content. Three Swiss spring wheat cultivars (‘Albis’, ‘Toronit’, ‘Pizol’) and an experimental line (‘L94491’) were grown without (N0; 0 kg N ha?1) and with high fertilizer N [(NH4NO3); (N1; 250 kg N ha?1) supply on a clay loam soil with low organic matter content. Biomass and nitrogen accumulation in biomass as well as the leaf growth and senescence patterns (SPAD) were investigated in an attempt to explain the physiology of growth and N translocation of these genotypes. The pre-anthesis accumulation of biomass and N in the biomass depended on genotype only at N1 in 2000. In this year, conditions were less favorable for the pre-anthesis accumulation of biomass and N, which was, on average, 10 and 20% lower, respectively, of the total than in 1999. The contribution of pre-anthesis assimilates to the grain yield (CPAY) was higher in 1999 for all genotypes (36.9%) compared to 2000 (13.5%) except ‘Toronit’. Between anthesis and maturity the climate influenced the genetic variability of some N use efficiency components: N translocation efficiency (NTE) and dry matter translocation efficiency (DMTE). NTE was higher in 1999 (68.1%) compared to 2000 (50.7%); 1999 was a year in which the post-anthesis period was drier and warmer than usual. ‘Toronit’ produced the highest biomass by maturity due mainly to greater and longer lasting green leaf area after anthesis. ‘Albis’ performed relatively well under low input conditions, with considerable amounts of N being re-translocated to the seeds at maturity (NHI), whereas ‘Pizol’ accumulated in grains N as high as for ‘L94491’. In a humid temperate climate breeding for greater N uptake and partitioning efficiency may be a promising way to minimize N losses and produce high phytomass and grain yields. Using high protein lines as selection material and combining them with high biomass genotypes may lead to high protein contents without decreasing yield. 相似文献
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不同品种油菜生长后期体内氮素转运及再分配差异研究 总被引：1，自引：0，他引：1
为探明影响油菜生长后期氮素再分配的生理因素及其与氮素利用效率的关系,本文在严格控制氮素供应水平的砂培条件下,采用15N示踪技术研究了不同氮素水平下2个油菜品种吸收氮素后在体内的分配、转运及损失情况。结果表明,供试2个油菜品种的生物产量、籽粒产量、籽粒含氮量、植株全氮、籽粒全氮、收获指数和氮收获指数均存在较大差异,且以上差异因氮素水平不同而有所不同。常氮处理下,品种"742"的生物产量、籽粒产量、籽粒全氮、收获指数和氮素收获指数均高于品种"814";低氮处理下,品种"742"的植株含氮量、籽粒含氮量、收获指数和氮素收获指数高于品种"814",而生物产量、籽粒产量、植株全氮和籽粒全氮低于品种"814"。采用15N示踪方法测定油菜生长后期氮素再分配的结果表明,供试油菜品种生长后期营养器官氮素减少量及其比例、转向生殖器官的氮素再分配量存在明显差异。不同氮素水平下,品种"742"大多数营养器官的氮素减少量均高于品种"814",而且茎的减少量差异最为明显。常氮水平下,品种"742"根、叶中氮素减少比例均少于品种"814",而茎中氮素减少量远远大于品种"814";低氮水平下,品种"742"根、茎、叶中氮素减少比例均大于品种"814"。在常氮和低氮处理下转向生殖器官的氮素再分配量均表现为,品种"742"向角果皮再分配的氮素低于品种"814",向籽粒再分配的氮素则高于"814"。T检验结果表明,2个品种除常氮条件下向角果皮再分配的氮素之外,其他再分配氮素的差异都达到显著水平,说明油菜生长后期由营养器官向生殖器官的氮素再分配有助于提高氮素利用效率。油菜生长后期氮素损失量表现为,品种"742"在常氮处理下的氮素损失量及其比例小于品种"814",低氮处理时反之。 相似文献
17.
Hai-Yan Duan Lei Shi Xiang-Sheng Ye Yun-Hua Wang Fang-Sen Xu 《Journal of plant nutrition》2013,36(7):1148-1163
ABSTRACT Plant species and genotypes within one species may significantly differ in phosphorus (P) uptake and utilization when they suffer from P starvation. The objective of this research was to screen P-efficient germplasm of oilseed rape (Brassica napus L.) and analyze the possible mechanism responsible for P efficiency by two-steps screening experiments and validation of P efficiency. Phosphorus efficiency coefficient at seedling stage, namely, ratio of shoot dry weight under low P to that under adequate P (PECS) of 194 oilseed rape cultivars varied from 0.050 to 0.62 and was significantly related with shoot dry weight under low P level (r = 0.859??, P < 0.01). Oilseed rape cultivar ‘Eyou Changjia’ presented the highest P efficiency coefficient in each growth stage and had the highest seed yield at low P, whereas oilseed rape cultivar ‘B104-2’ was the most sensitive to low P stress among the 12 candidate cultivars obtained from the two-steps screening experiments. Under low P condition in validation experiments of soil and solution cultures, ‘Eyou Changjia’ could produce much more dry matter and acquire more P than ‘B104-2.’ Moreover, P efficient coefficient obtained from the pot experiment was comparable to those from the field experiment. This might be attributed to high P uptake efficiency for ‘Eyou Changjia’ when it suffered from low-P stress. Comparison of results from the hydroponics with those from the pot and field experiments led to the conclusion that the P uptake efficiency in the hydroponics is highly related to that in soil culture conditions. These results show that there are large genotypic differences in response to phosphorus deficiency in oilseed rape germplasm (Brassica napus L.) and ‘Eyou Changjia’ is P-efficient and ‘B104-2’ is P-inefficient. By comparing these results further, the mechanism responsible for P efficiency was suggested to be mainly due to high P uptake efficiency by forming larger root system, and improving the ability of mobilizing and acquiring soil P in P-efficient oilseed rape under the condition of P starvation. 相似文献
18.
Previous studies showed that wide genotype differences in nitrogen (N) efficiency exists among cultivars of rapeseed (Brassica napus L.), but the mechanisms behind those differences are still unknown. In the present study, our aim was to analyze the adaptability mechanism of N-efficient rapeseed to low-N stress by employing two genotypes of natural variation in N efficiency. Nitrogen-efficient genotype, ‘BG51’, and N-inefficient genotype, ‘BG88’, were grown in a solution culture experiment under conditions of high-N (6.0 mM N) and low-N (0.6 mM N) supply. After growing 30 d, roots and shoots were sampled for the analysis of dry weight, N concentration and accumulation, N use efficiency (NUE), N transport efficiency (NTE), root system vigor parameters, nitrate redutase (NR) activity, and glutamine synthetase (GS) activity. Nitrogen deficiency decreased shoot and root dry weight significantly, but ‘BG51’ exhibited a significantly lower decrease in shoot dry weight and had significantly higher biomass production than ‘BG88’. Under low N supply ‘BG51’ accumulated more N in shoot, root and whole plant than ‘BG88’, and presented higher NUE in both shoot and root. Low-N stress induced an increase in maximum root length by 28.3% for ‘BG88’ and 55.1% for ‘BG51’ compared with the high-N treatment. And ‘BG51’ presented larger root volume, higher root vigor, larger root total absorbing area and root active absorbing area than ‘BG88’ in low-N treatment. Furthermore, ‘BG51’ had significantly higher NR and GS activity in both leaf and root in low N treatment than ‘BG88’, while there was no evident difference between them in high N treatment. These results suggested that N-efficient rapeseed germplasm of natural variation involves an integrated adaptability mechanism responding to low-N stress. Namely, N-efficient genotype could form more developed root system to accumulate more N, and presented efficient N assimilation by higher NR activity and GS activity than N-inefficient genotype. These ultimately resulted in high tolerance of N-efficient genotype to low-N stress and high biomass production. 相似文献
19.
不同氮效率油菜品种产量和品质对供氮水平的反应 总被引：3，自引：1，他引：2
为探明不同氮效率油菜产量和品质对供氮水平的反应动态,揭示油菜氮效率与品质的关系,本文采用砂培试验,研究了两种氮效率油菜品种在06、3、6、12、15 mmol/L 5种不同氮水平下（用N1N5表示）的氮效率、子粒产量和品质的变化。结果表明, 随着供氮水平的提高,油菜子粒产量、油分产量和蛋白质含量增加,氮效率和油分含量下降; 而子粒脂肪酸组成变化较小,所测定的7种脂肪酸中,芥酸和花生烯酸含量随着氮水平的增加略有下降,棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸含量则没有明显的变化; 与氮低效品种相比,氮高效品种的子粒产量、芥酸和花生烯酸含量随供氮水平的变化幅度更大,油分含量下降幅度更小。所有氮水平下,氮高效品种的子粒产量、油分含量和油分产量均高于氮低效品种,亚油酸含量略高于而亚麻酸含量略低于氮低效品种,子粒蛋白质、棕榈酸、硬脂酸、油酸含量两品种没有差异。总之,提高氮水平有利于增加油分产量,氮高效品种的增加幅度大于氮低效品种,但对脂肪酸组成的影响较小。因此,氮高效品种不会因高效吸收利用氮素而降低油分含量或使油菜品质变劣。 相似文献
20.
The availability of nitrogen (N) contained in crop residues for a following crop may vary with cultivar, depending on root traits and the interaction between roots and soil. We used a pot experiment to investigate the effects of six spring wheat (Triticum aestivum L.) cultivars (three old varieties introduced before mid last century and three modern varieties) and N fertilization on the ability of wheat to acquire N from maize (Zea mays L.) straw added to soil. Wheat was grown in a soil where 15N‐labeled maize straw had been incorporated with or without N fertilization. Higher grain yield in three modern and one old cultivar was ascribed to preferred allocation of photosynthate to aboveground plant parts and from vegetative organs to grains. Root biomass, root length density and root surface area were all smaller in modern than in old cultivars at both anthesis and maturity. Root mean diameter was generally similar between modern and old cultivars at anthesis but was greater in modern than in old cultivars at maturity. There were cultivar differences in N uptake from incorporated maize straw and the other N sources (soil and fertilizer). However, these differences were not related to variation in the measured root parameters among the six cultivars. At anthesis, total N uptake efficiencies by roots (total N uptake per root weight or root length) were greater in modern than in old cultivars within each fertilization level. At maturity, averaged over fertilization levels, the total N uptake efficiencies by roots were 292?336 mg N g?1 roots or 3.2?4.0 mg N m?1 roots for three modern cultivars, in contrast to 132?213 mg N g?1 roots or 0.93?1.6 mg N m?1 roots for three old cultivars. Fertilization enhanced the utilization of N from maize straw by all cultivars, but root N uptake efficiencies were less affected. We concluded that modern spring wheat cultivars had higher root N uptake efficiency than old cultivars. 相似文献