不同品种油菜氮效率差异及其生理基础研究

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。     

不同品种油菜氮效率差异及其成因分析

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。     

不同氮效率油菜品种产量和品质对供氮水平的反应

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06、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。     

施氮对不同品种玉米产量、氮效率的影响

随着人们对农田氮肥过量施用导致肥料利用率下降和农田地下水硝酸盐污染等问题认识的逐渐加深,不同品种玉米氮素营养效率的研究得到普遍重视。本文选择在我国主要应用的15个玉米品种,在0、120kg.hm 2、240 kg.hm 2氮水平下,通过田间试验研究了施氮对不同品种玉米产量和氮效率的影响。结果表明:"郑单958"、"32D22"、"滑玉14"、"豫丰335"、"新单29"、"中科11"和"漯单9号"在施氮量为120 kg.hm 2时产量最高;"先玉335"、"浚单18"、"蠡玉13"、"浚单20"、"农大108"、"NE8"、"豫禾988"和"洛玉4号"在施氮量为240 kg.hm 2时产量最高。以产量差异的显著性关系为标准进行聚类分析,可将15个玉米品种分为高产、中产、低产3个类型。在3个氮水平下,"蠡玉13"都表现为高产品种,"先玉335"都表现为中产品种,"豫丰335"和"豫禾988"都表现为低产品种。根据玉米在中氮和高氮水平下的氮效率,可以将其划分为4个类型,"郑单958"、"浚单20"、"蠡玉13"、"浚单18"和"漯单9号"为双高效型,"农大108"、"NE8"、"豫禾988"、"豫丰335"和"洛玉4号"为双低效型。根据产量和氮效率的聚类分析结果,"蠡玉13"和"浚单20"在中氮和高氮时都是高产又高氮效率的品种;"郑单958"和"漯单9"在中氮时是高产高氮效率的品种;而"豫丰335"、"豫禾988"、"NE8"和"洛玉4号"在中氮和高氮时都是低产又低氮效率的品种;"农大108"在高氮时是低产又低氮效率的品种。玉米产量与氮营养性状的相关性分析结果表明,氮吸收效率对产量的影响较小,氮素利用效率与秸秆吸氮量之间存在抑制作用,氮素利用效率与氮收获指数间有很好的协同作用。通径分析结果表明,在3个施氮水平下,玉米氮素利用效率对产量有较大的作用,而氮素吸收效率对产量的作用很小。在低氮水平下,氮素利用效率和籽粒吸氮量对产量起决定性作用;在高氮水平下,氮素利用效率起主要作用。     

不同供氮水平下油菜品种硝态氮累积利用特征与氮效率差异

以两种氮效率不同的油菜品种X-13和X-29为材料,在严格控制氮营养水平的砂培条件下,研究了不同施氮水平下两个品种油菜硝态氮累积量、硝酸还原酶活性、氮素吸收量、籽粒产量、氮效率等指标的差异特征。结果表明,与氮低效品种X-29相比,氮高效品种X-13的硝态氮累积量多,硝态氮再利用量大,叶片硝酸还原酶活性高,其氮素累积量也多,籽粒产量和氮效率也高,品种间差异显著。供氮水平提高,两品种的硝态氮累积量和再利用量都增大,叶片硝酸还原酶活性增强,氮素随着累积量增加,籽粒产量升高,而氮效率则下降。     

不同氮效率水稻品种苗期吸氮效率差异及其机理研究

以大田筛选得到的不同生物学特性的12个水稻品种为材料,研究了水培条件下这些品种苗期的吸N效率差异,结果表明大田N效率不同的品种在苗期水培条件下吸N效率也不相同,并且大田相同类型的品种在苗期N效率也不完全相同。供试7个大田高产品种中只有桂单4号、云粳38和黔育421这3个水稻品种在水培环境中同样保持较其它品种生物量大,N响应高的特性;另外3个大田高产品种南光、予粳7号和4007在苗期N效率表现很差;红稻Vmax虽然很大,但是生物量很小,所以综合表现一般。3个低产品种Elio、抚宁小红芒和黄金糯中,Elio在苗期N效率很高,另外2个品种N效率不高。研究发现,生物量(尤其是根系的生物量)和对NH4 的亲和力(1/Km)以及Vmax是水稻苗期吸N效率的主要决定因素。典型的苗期N高效品种有桂单4号、黔育421、Elio和云粳38,这些品种苗期N累积量高,N响应值高,原因在于桂单4号、黔育421和Elio在水平增加后Vmax都成倍增加,尤其Elio的Vmax一直都很高,而云粳38则主要是靠较高的生物量来获得高吸N量。典型的低效品种有南光、4007、武运粳7号和予粳7号,这些品种N累积量小,N响应值小,原因在于其中前3个品种在N水平增加后Vmax都降低,Km大幅度增加,而予粳7号虽然Vmax稍有增加,但亲和力则降低最大而成为所有品种中最低的,所以综合结果仍是低效。     

不同基因型玉米氮效率差异的比较研究

随着人们对农田氮肥过量施用导致肥料利用率下降和农田地下水硝酸盐污染等问题认识的逐渐加深,不同基因型玉米氮素营养效率的研究得到了普遍的重视。田间条件下选择３５个玉米基因型,在３个施氮水平下测定其产量、氮效率和氮响应度特性状、结果表明,在同一施氮水平下,不同基因间接量,氮效率和氮响应度存在显著的差异。以张氮响应度为指标进行的模糊聚类分析结果表明,当λ＝０．８２时,供式玉米基因型可以划分为四种类型。结果     

不同马铃薯品种的氮效率差异研究

研究不同马铃薯品种氮效率的差异,为氮高效马铃薯品种栽培种植提供参考依据.2016年在大田条件下,设置低氮(150 kg/hm2)和常规氮(300 kg/hm2)两个施氮水平,对27个马铃薯品种氮效率差异及其相关指标进行分析.结果表明,两个施氮水平下,供试马铃薯品种各性状指标均存在差异.以低氮条件下产量平均值、常规施氮条...     

供氮水平对不同氮效率玉米物质积累及产量的影响

在3个氮水平(N 0、150、300 kg·hm~(-20)下,采用大田盆栽试验研究氮肥对不同氮效率玉米品种干物质积累、分配及产量的影响。结果表明,氮高效品种正红311各阶段干物质积累量、积累速率均显著高于氮低效品种先玉508,尤其在3个氮水平下,成熟期氮高效品种正红311单株干物质较氮低效品种先玉508分别高37.63%、43.97%、35.28%。施氮使单株干物质积累量增加,在中低氮(B2)下正红311增加幅度大于先玉508,而在高氮(B3)处理下增幅低于先玉508;而先玉508的花前干物质贡献率较正红311高9.80%,且施氮增加了氮高效品种正红311花后物质贡献率,以及氮低效品种先玉508的花前物质贡献率。氮高效品种正红311籽粒的分配比例较先玉508低了8.07%,施氮使籽粒的分配比例增加,且氮高效品种正红311增加了14.35%,氮低效品种先玉508增加了11.53%。各处理下正红311的产量显著高于先玉508的产量,且均随施氮量的增加而增加,正红311的增产幅度显著高于先玉508,尤其是在中低氮水平(B2)下,达24.53%。氮高效品种较氮低效品种具有较高的物质生产能力,在低氮下具有较高的产量优势,而氮低效品种在高氮水平下有利于产量的发挥。     

磷素子粒生产效率不同品种的小麦磷素吸收利用差异

盆栽试验研究了130份小麦不同生育时期的干物重、磷素含量、子粒产量等指标,采用组内最小平方和的动态聚类方法将供试品种按磷素子粒生产效率从低到高依次分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ 6个类型,研究不同类型磷素吸收利用的差异。结果表明: 1）供试品种的磷素子粒生产效率差异较大（CV=1660%）,Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ类品种的平均磷素子粒生产效率为P 13629、15167、16916、18589、20132、24466 g/g。子粒产量随磷素子粒生产效率提高呈增加趋势（r=03203**）。2）不同生育时期,小麦植株磷浓度与吸磷量类型间差异显著或极显著。成熟期磷素子粒生产效率与植株磷浓度极显著正相关（r=06969**）,子粒产量与抽穗期、成熟期植株吸磷量显著或极显著相关（r=02966*、r=09271**）。3）不同生育时期磷素干物质生产效率的类间差异均达显著水平; 成熟期磷素干物质生产效率与磷素子粒生产效率极显著正相关 （r=07391**）。4）拔节期、抽穗期和成熟期干物重均表现出随磷素子粒生产效率增加而增加的趋势,成熟期尤为突出。拔节期成熟期磷素吸收量是影响子粒产量形成的重要因素,磷素子粒生产效率高的品种在拔节期后有较强干物质和子粒产量形成能力。     

Root growth and N‐uptake activity of oilseed rape (Brassica napus L.) cultivars differing in nitrogen efficiency

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.     

甘蓝型油菜不同氮素子粒生产效率品种的氮素分配特性研究

以甘蓝型常规油菜品种（2006～2007年度73个、2007～2008年度98个）为材料,通过测定成熟期不同器官干重、氮素含量,采用组内最小平方和动态聚类方法对供试品种的氮素子粒生产效率（NUEg） 进行聚类并研究了不同NUEg 类型的氮素积累与分配特性。结果表明,不同类型间NUEg达显著差异。随着NUEg增加,子粒产量、子粒氮素积累量以及子粒中的氮素占全株氮素比例都逐渐增加;而茎枝和果壳中的氮素积累量以及占全株氮素的比例都逐渐减小。生产上提高油菜NUEg,可以通过高NUEg品种的选择以及合理栽培措施调节使营养器官氮素更多向子粒中输送。     

On-farm trials of site-specific N management for maximum winter oilseed rape (Brassica napus L.) yield

Site-specific nitrogen (N) fertilizer strategy based on soil mineral N (N_min) test is crucial for maintaining high crop yield and high N-use efficiency. A two-year field experiment was conducted to develop a site-specific N fertilizer management for winter oilseed rape in the 2011–12 and 2012–13 seasons in Wuhan, central China. In contrast to fixed N fertilizer recommendation (FN), the use of the N_min test could optimize the N fertilizer inputs in time to fulfill crop N uptake during different growth stages and achieve high seed yield. Despite annual variations in seed yields and N fertilizer recommendations, the N recovery efficiency of the site-specific N fertilizer (SN) treatment was higher than that of the FN treatment. Consequently, the soil-based N strategy matches crop N uptake and soil N supply and achieves high yield depending on the site-specific soil-crop conditions.     

肥料运筹方式对冬油菜生长及产量的影响

以湘杂油763为供试材料,研究了不同肥料运筹方式对冬油菜产量和部分农艺性状的影响。结果表明：氮肥运筹方式对油菜生长的影响较大,以基肥:苗肥:薹肥 = 5:2:3处理的籽粒产量最高,其次是基肥:苗肥:薹肥 = 6:2:2处理,基肥:苗肥:薹肥 = 10:0:0处理的产量最低,其差异达到了显著水平,单株角果数、每角果粒数、绿叶数、茎粗、最大叶长和叶宽、叶片叶绿素含量等指标也有类似的变化趋势,而氮肥运筹方式对千粒重的影响不显著。磷肥和钾肥运筹方式对油菜生长的影响较小,在不同磷钾肥运筹方式下籽粒产量、产量构成因素、茎叶性状均没有显著差异。在本试验所设的8种处理中,以氮肥的基肥:苗肥:薹肥 = 5:2:3、磷肥和钾肥的基肥:苗肥:薹肥 = 10:0:0 处理和氮肥的基肥:苗肥:薹肥 = 5:2:3、磷肥的基肥:苗肥:薹肥 = 6:2:2、钾肥的基肥:苗肥:薹肥 = 10:0:0 处理的籽粒产量并列最高。     

油菜NO3-的吸收、分配及氮利用效率对低氮胁迫的响应

【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。     

Regulatory effects of sulfur on oilseed rape (Brassica napus L.) response to selenite

Selenite is a form of selenium (Se) commonly found in Se-excessive soils. To regulate the Se content in plants in high-Se areas, a potted soil experiment was performed on oilseed rape (Brassica napus L.) to evaluate the effects of varied amounts of sulfur (S) on the biomass, accumulation and distribution of Se in B. napus under the conditions of different amounts of Se in the soil. The results showed that the seedlings of B. napus were more sensitive to Se than the mature plants were. The addition of S significantly alleviated the growth inhibition in seedlings and facilitated the growth of mature plants under higher Se (15 mg kg^?1) conditions. S treatment significantly decreased soil pH within the range of 0.22–0.60. An appropriate moderate amount (150 mg kg^?1) of S exerted the strongest inhibition on Se concentration and accumulation in B. napus at the seedling stage, but a higher amount (300 mg kg^?1) of S led to a more significant decrease in the mature plants under higher Se conditions, with the maximum reduction in various parts of B. napus reaching 51.3–60.9% and 42.5–53.4%, respectively. The application of S only affected the uptake of Se, and not the translocation of Se; the accumulation of Se in B. napus follows the sequence of pod ≈ stem > rapeseed > root, and the distribution ratio is approximately 1.00:0.97:0.69:0.49. Overall, the application of S alleviated the inhibitory effect on growth caused by excessive Se by reducing the Se concentration in B. napus and facilitating its growth, suggesting that S treatment is a suitable and highly cost-effective method to regulate the content of Se in B. napus.     

磷肥对甘蓝型春油菜产量、磷肥利用效率及经济效益的影响

利用大田试验研究了不同磷肥用量对甘蓝型春油菜产量、养分积累、磷素利用效率和经济效益的影响。结果表明,在低磷土壤上施用125 kg/hm2N和135 kg/hm2K2O基础上增施磷肥,可显著增加油菜不同部位产量,其中籽粒产量平均提高12.5%,生物量平均提高29.0%。施磷明显提高油菜地上部P素含量,有利于促进油菜K素营养累积,但对N素、K素含量无显著影响。随磷肥施用量的增加,磷肥偏生产力显著下降,施磷后磷肥农学效率、磷肥表观利用率和磷肥生理利用率平均分别为4.6 kg/kg P2O5、13.0%和40.2 kg/kg P2O5,磷肥对籽粒产量的贡献率仅为10.9%。根据经济效益分析结果,青海甘蓝型春油菜生产中磷肥用量以75 kg/hm2为宜。     

Effect of cadmium on the chemical composition of xylem exudate from oilseed rape plants (Brassica napus L.)

Abstract

Phytoremediation is a good technique for removing cadmium (Cd) from farmland soils. To remove Cd from these soils effectively, it is necessary for Cd ions to be transported to the shoot organs for later harvest. However, the mechanism of Cd translocation to shoot organs via xylem vessels has not yet been elucidated. We selected oilseed rape plants (Brassica napus L.) and established a method to collect xylem exudates from these plants. After 3 days of Cd treatment (10 µmol L^?1 and 30 µmol L^?1) the Cd concentrations in the xylem exudates were approximately 6.5 µmol L^?1 and 16 µmol L^?1, respectively. The detection of Cd in the xylem exudate indicated that Cd was moving to shoot organs via xylem vessels. The effect of these Cd treatments on the amino acid, organic acid and protein composition of xylem exudates from oilseed rape plants was investigated. The level of amino acids and organic acids detected was enough to bind Cd transported via the xylem. Sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis revealed that proteins with molecular weights of 36 kDa and 45 kDa clearly increased in the exudates with Cd treatment. The possibility that these compounds are binding Cd in the xylem exudates was discussed.