Growth, senescence and water use efficiency of spring oilseed rape (Brassica napus L. cv. Mozart) grown in a factorial combination of nitrogen supply and elevated CO2
Growth, senescence and water use efficiency of spring oilseed rape (Brassica napus L. cv. Mozart) grown in a factorial combination of nitrogen supply and elevated CO2
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DOI：
10.1016/j.envexpbot.2011.04.003
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发表时间：
2011-09-01
影响因子：
5.7
通讯作者：
Fangmeier, A.
中科院分区：
文献类型：
--
作者：
Franzaring, J.;Weller, S.;Fangmeier, A.
大气CO2浓度的增加将影响C3植物对水、养分和光照的资源利用效率。油菜（OSR）对CO2浓度升高的反应还没有得到太多的解决。由于作物的氮利用效率低，CO2富集和氮供应的相互作用值得特别关注。春季OSR生长在气候室模拟白天长度和温度的季节性增加在西南部德国。采用代表75、150和225 kg ha（-1）的三种氮肥水平和两种CO2浓度（380和550 μ mol mol（-1））来研究源库关系、植物发育和衰老、干物质生产的水分利用效率（WUeprod.）分配模式对不同组分、生长、产量和种子含油量的影响。在播种后72至142天（DAS）之间进行了7次收获。总体而言，室内植物表现与田间条件下的发育相当。虽然CO2的反应是小的植物接受最低的N-水平，几个显着的N × CO2的相互作用中观察到的其他治疗。增加氮的可用性导致更长的开花窗口，这进一步延长在CO2浓度升高。然而，显着较少的生物量分配到生殖结构CO2浓度升高，而营养C-存储器官继续增长。在最后收获的地上部质量的CO2暴露的植物增加了9.8%和15%，在低，中，高N处理。根生长增加甚至更多的17，43和33%，分别和WUEprod。分别增长了23%、42%和35%。同时，在氮素供应充足的情况下，CO2施肥显著降低了种子含油量，说明在高氮条件下，CO2施肥导致了营养组织的过度生长，而生殖结构则受到了损害。源库关系的中断刺激了侧枝和花（分枝）的形成。虽然可以排除CO2浓度升高对开花的直接影响，但我们假设高N和CO2供应下的生长增加造成了营养失衡，从而影响了开花和结实，然而，最终的种子常量营养素浓度略有增加CO2浓度升高，表明营养从源（叶）到汇（种子）的再动员仍然有效。这些研究结果得到了支持的较低的氮浓度在衰老的叶片，可能增加N的再动员到其他植物部分下的CO2浓度升高。尽管如此，CO2浓度增加导致种子含油量下降，这可能导致作物质量下降。(C)2011 Elsevier BM. All rights reserved.
Atmospheric CO2 enrichment is expected to affect the resource use efficiency of C3 plants with respect to water, nutrients and light in an interactive manner. The responses of oilseed rape (OSR) to elevated CO2 have not much been addressed. Since the crop has low nitrogen use efficiency, the interactive effects of CO2 enrichment and nitrogen supply deserve particular attention.Spring OSR was grown in climate chambers simulating the seasonal increments of day length and temperature in South-Western Germany. Three levels of N fertilisation representing 75, 150 and 225 kg ha(-1) and two CO2 concentrations (380 and 550 mu mol mol(-1)) were used to investigate changes in source-sink relationships, plant development and senescence, water use efficiency of the dry matter production (WUEprod.), allocation patterns to different fractions, growth, yield and seed oil contents. Seven harvests were performed between 72 and 142 days after sowing (DAS).Overall, plant performance in the chambers was comparable to the development under field conditions. While CO2 responses were small in the plants receiving lowest N-levels, several significant N x CO2 interactions were observed in the other treatments. Increasing the N availability resulted in longer flowering windows, which were furthermore extended at elevated CO2 concentrations. Nevertheless, significantly less biomass was allocated to reproductive structures under elevated CO2, while the vegetative C-storing organs continued to grow. At the final harvest shoot mass of the CO2 exposed plants had increased by 9.8 and 15% in the low, medium and high N treatments. Root growth was increased even more by 17, 43 and 33%, respectively and WUEprod. increased by 23, 42 and 35%. At the same time, seed oil contents were significantly reduced by CO2 enrichment in the treatments with ample N supply.Obviously, under high N-supply, the CO2 fertilisation induced exaggerated growth of vegetative tissues at the expense of reproductive structures. The interruption of source-sink relationships stimulated the formation of side shoots and flowers (branching out). While direct effects of elevated CO2 on flowering can be excluded, we assume that the increased growth under high N and CO2 supply created nutrient imbalances which hence affected flowering and seed set.Nevertheless, the final seed macronutrient concentrations were slightly increased by elevated CO2, indicating that remobilisation of nutrients from the sources (leaves) to the sinks (seeds) remained effective. These findings were supported by the lower nitrogen concentrations in senescing leaves and probably increased N remobilisation to other plant parts under elevated concentrations of CO2. All the same, CO2 enrichment caused a decline in seed oil contents, which may translate into a reduced crop quality. (C) 2011 Elsevier BM. All rights reserved.