Leaf nitrogen distribution to maximize the canopy photosynthesis in rice
Leaf nitrogen distribution to maximize the canopy photosynthesis in rice
复制标题
DOI：
10.1016/j.fcr.2005.04.005
复制
发表时间：
2006-02-15
影响因子：
5.8
通讯作者：
Ishii, R
中科院分区：
文献类型：
--
作者：
Shiratsuchi, H;Yamagishi, T;Ishii, R
估算了灌浆期水稻冠层中叶氮 (N) 的最佳分布，以实现最大日冠层光合作用 (DCP) 以及对 DCP 的优化效果。使用盆中以低密度生长直至抽穗的植物，在抽穗时建立低密度和高密度冠层（28.3和47.5株m(-2)）和孤立植物，以使两个冠层和孤立植物在处理开始时除了植物密度和相同的叶氮分布外具有相同的冠层结构。模拟在叶片氮含量上限2个条件下进行。条件1下叶片氮含量上限为1.80 g m(-2)。条件2下，测量抽穗时各叶位的叶片氮含量上限。该模型表明，如果可以增加上部叶片的氮含量，同时减少下部叶片的氮含量，则在任何植物密度、光照条件以及条件 1 和 2 下，DCP 都会增加。在晴朗的日子里，在条件 1 下，低密度冠层和高密度冠层的 DCP 估计分别增加 19-45% 和 38-70%。即使在比条件 1 更现实的条件 2 下，低密度和高密度冠层的增幅也分别高达 21% 和 25%。通过当前模型获得的这些估计值，包含圆锥花序和茎对 DCP 的遮蔽影响，高于之前的报告，其中没有考虑颗粒和茎的遮蔽影响。在观察到的叶氮分布中，植物密度越高，叶氮梯度越陡。高密度冠层中的梯度更接近于预测的最佳叶片氮分布，并且可能有助于维持冠层中较高的DCP。与在孤立植物中观察到的叶子氮分布梯度更为平缓的假设情况相比，在冠层中观察到的叶子氮含量保持较陡的梯度估计会使高密度冠层和低密度冠层中的 DCP 分别增加 13% 和 5%。 (c) 2005 Elsevier B.V. 保留所有权利。
The optimum distribution of leaf nitrogen (N) in the canopy of rice plants (Oryza sativa L.) for maximum daily canopy photosynthesis (DCP) and the optimization effects on DCP were estimated during the grain filling period. The low- and high-density canopies (28.3 and 47.5 plants m(-2)) and isolated plants were established at heading using plants in pots grown up at the low density until heading to make the same canopy architecture except plant density and the same leaf N distribution at the start of treatment among the two canopies and the isolated plants. The simulation was conducted under two conditions of the upper 2 limit of leaf N. Under condition 1, upper limit of leaf N content was 1.80 g m(-2). Under condition 2, upper limits were measured leaf N content in each leaf position at heading. The model indicates that if leaf N content in the upper leaves can be increased with reduction of N in the lower leaves, DCP will increase in any of the plant density, light conditions and under conditions 1 and 2. On a clear day, the estimated increase in DCP was 19-45 and 38-70% in the low- and high-density canopies under condition 1, respectively. Even under condition 2, which is more realistic than condition 1, the increase was up to 21 and 25% in the low- and high-density canopies. These estimates obtained by the present model that incorporates the shading effects of panicles and stems on DCP were higher than the previous reports which did not consider the effects of shading by particles and stems. In the observed leaf N distribution, the higher the plant density was, the steeper the gradient of the leaf N remained. The gradient in the high-density canopy was closer to that of the predicted optimum leaf N distribution, and likely to contribute to maintaining higher DCP in the canopies. Compared with the hypothetical case in which gradient of leaf N distribution would be more gentle as observed in the isolated plants, the maintained steeper gradient of observed leaf N content in the canopies was estimated to increase DCP by 13 and 5% in the high- and low-density canopy, respectively. (c) 2005 Elsevier B.V. All rights reserved.