| Project/Area Number |
10460008
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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 | TOHOKU UNIVERSITY |
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Principal Investigator |
NISHIYAMA Iwao GRADUATE SCHOOL OF AGRICULTURAL SCIENCE, TOHOKU UNIVERSITY, PROFESSOR, 大学院・農学研究科, 教授 (30292254)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAJIMA Takayuki FACULTY OF AGRICULTURE, TOHOKU UNIVERSITY, RESEARCH ASSISTANT, 農学部, 教務職員 (80241553)
NAKAMURA Teiji GRADUATE SCHOOL OF AGRICULTURAL SCIENCE, TOHOKU UNIVERSITY, RESEARCH ASSOCIATE, 大学院・農学研究科, 助手 (70155844)
GOTO Yusuke GRADUATE SCHOOL OF AGRICULTURAL SCIENCE, TOHOKU UNIVERSITY, ASSOCIATE PROFESSOR, 大学院・農学研究科, 助教授 (80122919)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥13,800,000 (Direct Cost: ¥13,800,000)
Fiscal Year 1999: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1998: ¥10,100,000 (Direct Cost: ¥10,100,000)
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| Keywords | rice / cool-weather damage / cool-weather resistance / unfertilization / pollen grain / root amount / nitrogen / phytohormone / 多窒素 / 葯長 / 施肥量 / 土壌水分 / 相対的根量 / 充実花粉数 |
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| Research Abstract |
1. Focus of the research on cool-weather damage in rice plants
Literatures were reviewed for research on cool-weather damage in rice plants, and the elucidation of the causal sequence from nitrogen application to unfertilization, placing a particular focus on the number of pollen grain in the anther, was pointed out to be highly important for the understanding of the physiological mechanism of the sterility-type cool-weather damage.
2. Varietal difference in the number of pollen grains
The number of pollen grains was larger in clutivars and lines with more highly resistant to the cool weather damage. It showed a tendency, however, to be divided into two subgroups within each group of the same ranking of resistance. This fact implies that a genetic factor other than pollen number is relating to the degree of cool-weather damage.
3. Importance of the relative amount of roots
The root/leaf-stem-panicle ratio or the root/spikelet ratio showed a high correlation with the fertility of plants which were cooled at the critical stage. This fact implies that the relative amount of roots to aerial parts of the plant or the number of spikelets is relating to the degree of the cool-weather resistance.
4. Variations in the number of pollen grains due to cultivation conditions
The number of pollen grains decreased with an application of larger amount of nitrogen fertilizer. An application of larger amount of phosphate fertilizer counteracted to this nitrogen application and recovered decreased number of pollen grains, resulting in the recovery of unfertilization also. The number of pollen grains decreased by a condition of lower solar incidence.
5. Effect of phytohormone
Gibberellin or cytokinin or the mixture of them augmented the degree of unfertilization induced by cool temperatures at the critical stage.
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