Comparative response of wheat and oilseed rape to nitrogen supply: absorption and utilisation efficiency of radiation and nitrogen during the reproductive stages determining yield
Comparative response of wheat and oilseed rape to nitrogen supply: absorption and utilisation efficiency of radiation and nitrogen during the reproductive stages determining yield
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DOI：
10.1023/a:1004757124939
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发表时间：
2000-01-01
期刊：
影响因子：
4.9
通讯作者：
Rabbinge, R
中科院分区：
文献类型：
--
作者：
Dreccer, MF;Schapendonk, AHCM;Rabbinge, R
我们研究了春小麦和油菜对氮 (N) 供应的响应，重点关注籽粒数定义和籽粒灌浆的关键时期。农作物在避难所下的容器中生长，并用五种氮肥组合进行处理。在校正生物质合成（SC）成本后，小麦和油菜产生了相当数量的生物质和产量。从生物量和产量对后期施氮的响应以及动员生物量对产量的明显贡献来看，油菜的产量似乎比小麦在灌浆期更受来源限制，特别是在中高氮水平下。两个物种从土壤中的总有效氮中回收了等量的氮，并且具有相似的氮利用效率（以每单位吸收氮的产量表示）。然而，油菜生物量中吸收氮的转化效率较高，但氮收获指数低于小麦。油菜的根生物量与小麦相似或更低，具体取决于氮水平，但单位土壤体积的根长度和比根长度更高。粒数关键期单位根干重对氮的比吸收率，油菜高于小麦。在小麦中，氮限制通过合成成本校正的辐射利用效率（RUESC）与截获的光合有效辐射累积量（IPARc）类似或更低的减少来影响生长。在油菜中，由于氮缺乏而导致的生长缓慢与 RUESC 的相关性大于与 IPARc 的相关性，在开花期间和灌浆期间，这两种成分都对生长下降产生了类似的影响。从开花到成熟，RUESC和叶片和花序中的N浓度（LIN%）呈曲线相关。在高氮供应下，在粒数决定的关键时期，油菜的 RUESC 往往高于小麦，而在灌浆期则普遍较低。从不同器官的光合效率和生殖阶段源库比的变化来讨论这些差异的原因和增加产量潜力的可能性。
We investigated the response of spring wheat and oilseed rape to nitrogen (N) supply, focusing on the critical period for grain number definition and grain filling. Crops were grown in containers under a shelter and treated with five combinations of applied N. Wheat and oilseed rape produced comparable amounts of biomass and yield when corrected for the costs of biomass synthesis (SC). From the responses of biomass and yield to late N applications and the apparent contribution of mobilised biomass to yield, it seems that the yield of oilseed rape was more source-limited during grain filling than that of wheat, particularly at the medium and high N levels. Both species recovered equal amounts of N from the total available N in the soil and had similar N use efficiencies, expressed as yield per unit of N absorbed. However, oilseed rape had higher efficiency to convert absorbed N in biomass, but lower harvest index of N than wheat. Oilseed rape had similar or lower root biomass than wheat, depending on N level, but higher root length per unit soil volume and specific root length. The specific uptake rate of N per unit root dry weight during the critical period for grain number determination was higher in oilseed rape than in wheat. In wheat, N limitation affected growth through a similar or lower reduction in radiation use efficiency corrected for synthesis costs (RUESC) than in the cumulative amount of intercepted photosynthetically active radiation (IPARc). In oilseed rape, lower growth due to N shortage was associated more with RUESC than IPARc, during flowering while during grain filling both components contributed similarly to decreased growth. RUESC and the concentration of N in leaves and inflorescence (LIN%) decreased from flowering to maturity and were curvilinearly related. Oilseed rape tended to have higher RUESC than wheat at high N supply during the critical period for grain number determination, and generally lower during grain filling. The reasons for these differences and possibilities to increase yield potential are discussed in terms of the photosynthetic efficiency of the different organs and changes in source-sink ratio during reproductive stages.