A comparison of the accumulation and partitioning of nitrogen in plants between two rice cultivars, Akenohoshi and Nipponbare, at the ripening stage
A comparison of the accumulation and partitioning of nitrogen in plants between two rice cultivars, Akenohoshi and Nipponbare, at the ripening stage
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DOI：
10.1626/pps.6.172
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发表时间：
2003-09-01
影响因子：
2.5
通讯作者：
Hirasawa, T
中科院分区：
文献类型：
--
作者：
Ookawa, T;Naruoka, Y;Hirasawa, T
为了阐明高产水稻品种Akenohoshi在成熟期维持高光合速率的因素，与日本标准品种日本晴相比，我们调查了叶片的氮含量，重点是氮在水稻植株中的积累和分配。在成熟期，无论是田间还是盆栽，显之星的叶片氮含量都比日本晴高，而且无论品种和处理如何，光合速率与氮含量之间都存在密切的相关性。在抽穗前和成熟期，全株氮素积累量以明之星为最高，日本晴为最低。在成熟期，氮素分配到叶片的程度在Akenohoshi高于日本晴，而分配到穗的程度低于日本晴。日本晴增施氮肥后，叶片中氮素含量增加，这是由于全株氮素积累量增加，氮素向叶片的分配增强。我们的研究结果表明，较高的氮含量的Akenohoshi叶片是由于更多的氮积累在抽穗前和成熟期的植物和更有效的氮分配到叶片在成熟期，这导致了在成熟期间维持高光合速率。
To clarify the factors responsible for the maintenance of a high rate of photosynthesis at the ripening stage in the high-yield rice cultivar Akenohoshi, as compared with that in a Japanese standard cultivar, Nipponbare, we investigated the nitrogen content of leaves, focusing on the accumulation and the partitioning of nitrogen in rice plants. The nitrogen content of leaves of plants that were grown in the field or in pots remained higher in Akenohoshi than in Nipponbare during the ripening stage, and there was a close correlation between the rate of photosynthesis and the nitrogen content irrespective of cultivar and treatment. The accumulation of nitrogen in the whole plant was greater in Akenohoshi than in Nipponbare before heading and during the ripening stage. The extent of partitioning of nitrogen to leaves was higher and that to ears was lower in Akenohoshi than in Nipponbare during the ripening stage. By application of additional nitrogen fertilizer to Nipponbare, the nitrogen content of leaves was increased as a result of the increased accumulation of nitrogen in the whole plant and the enhanced partitioning of nitrogen to leaves. Our results indicate that the higher nitrogen content of Akenohoshi leaves was due to the greater accumulation of nitrogen in the plant before heading and during the ripening stage and the more effective partitioning of nitrogen to leaves during the ripening stage, which resulted in the maintenance of a high rate of photosynthesis during ripening.