| Project/Area Number |
14360008
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
作物学
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| Research Institution | National Institute for Agro-Environmental Sciences (2003-2004)
Hokkaido University (2002) |
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Principal Investigator |
HASEGAWA Toshihiro National Institute for Agro-Environmental Sciences, Department of Global Resources, Chief, 地球環境部, 研究リーダー (10228455)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Hidemitsu National Institute for Agro-Environmental Sciences, Department of Global Resources, Senior Researcher, 地球環境部, 主任研究官 (00354051)
OKADA Masumi National Agricultural Research Center for Tohoku Region, Department of Biology and Environment Sciences, Team Leader, 生物系特定産業技術研究機構・東北農業研究センター・地域基盤研究部, チーム長 (10355274)
JITSUYAMA Yutaka Hokkaido University, Graduate School of Agriculture, Assistant Professor, 大学院・農学研究科, 助手 (90322841)
KOBAYASHI Kazuhiko University of Tokyo, Graduate School of Agricultural and Life Sciences, 大学院・農学生命科学研究科, 教授 (10354044)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥10,600,000 (Direct Cost: ¥10,600,000)
Fiscal Year 2004: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2002: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | Developmental Rate / Elevated CO_2 / Free air CO_2 enrichment (FACE) / Genotypic variation / Lamina length / Oryza sativa L. / Photosynthetic rate / Sink size / 一穂穎花数 / 着粒突然変異系統 / 乾物生産 / チャンバー実験 / 水稲 / 出穂期 / 出葉速度 / 温度勾配型CO_2制御装置 / 開放系CO2増加(FACE) / 大気CO_2濃度 / 窒素反応 / 温度反応 / 発育 |
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| Research Abstract |
Growth enhancement of rice by elevated CO_2 can be mediated by the developmental and morphological traits. Much has been studied for the photosynthetic responses but understandings on the effects of elevated CO_2 on morphogenesis of rice are still limited. We therefore attempted to determine the effects of elevated CO_2 (200μmol/mol above ambient) on development and morphology or rice varieties differing in maturity and plant types. Naturally sun-lit growth chambers and free air CO_2 enrichment (FACE) facilities were used for the experiments. Elevated CO_2 advanced heading dates of medium maturing varieties but did not foster development of two early varieties. A contrasting response of lamina length to elevated CO_2 was also observed among the genotypes ; a significant positive effect was found in early varieties but a negative one in medium varieties. The genotypic difference in CO_2 responses of leaf appearance and lamina length occurred mainly in the upper three to four leaves, which developed after panicle initiation. The results suggest that the genotype x CO_2 interaction on the developmental time can influence leaf number and lamina size which have a direct relevance to the rice productivity. We also tested whether genotypic difference in panicle size influences the growth responses to elevated CO_2 using a mutant with limited spikelet number. A parent and its mutant showed a similar growth enhancement due to elevated CO_2 despite the mutant having only 50-60 % of spikelet number per panicle, suggesting that limited spikelet per se does not limit growth enhancement. In all experiments, genotypic variation in photosynthetic responses to elevated CO_2 was mainly due to the difference in leaf greenness or nitrogen content. The results suggest that genotypic variation in growth responses to elevated CO_2 can mostly ascribed to the traits associated with development and nitrogen nutrition.
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