| Project/Area Number |
06660021
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
作物学
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| Research Institution | Shiga Prefectural Junior College |
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Principal Investigator |
SHIRAIWA Tatsuhiko Shiga Prefectural Junior College, Department of Agronomy, Instructor, 農学科, 助手 (30154363)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | rice / growth and yield / nitrogen uptake / nitrogen use efficiency / genetic variability / leaf area / radiation use efficiency / photosynthesis / 低投入 / 収量 / 品種 / 乾物生産 / 窒素濃度 / 水稲 / 品種間差異 / 窒素分配 / 葉身窒素含量 |
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| Research Abstract |
Three studies were conducted to determine genetic variability of nitrogen use efficiency (NUE) in grain and biomass production in rice crop. (1) Experiments during four years to quantify the relationship between N supply and dry matter productivity in Nipponbare rice with reference to canopy development from 1991 to 1994. (2) A comparison of NUE among 64 genotypes including Japanese and Asian old/modem cultivars. (3) Comparisons of nitrogen utilization pattern and dry matter production among 8 cultivars with short and high statures in 1998 and between Nipponbare and a high-yielding F1 rice from China in 1994 and 1995.
(1) The response of dry matter productivity to N in the leaf canopy of Nipponbare was fairly stable across the four years and the nine conditions (3 N fertilizations * 3 planting densities). Curvilinear responses to N of light interception and radiation-use efficiency (RUE) were determined, (2) Grain yield per unit absorbed N varied from -35 to +24% to the standard cultivars Nipponbare and highest in the modem high-yielding cultivars mainly by their high harvest indices. Biomass yield ranged from -11 to +14% to Nipponbare standard and some Chinese local cultivars with very tall stature showed high productivity as well as the high-yielding cultivars. (3) N allocation in canopy development between leaf area (LAI) development and specific leaf N (SLN) content varied between short and high statured cultivars. This difference affected dry matter productivity. Greater LAI resulting in greater light interception and higher SLN resulting in high RUE. favored dry matter production under very low and medium to sufficient N availability, respectively. High-yielding Fl rice showed superior RUE than Nipponbare even at the similar SLN and this was attributed to higher N use efficiency in leaf photosynthesis and steeper N gradient in the leaf canopy.
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