1996 Fiscal Year Final Research Report Summary
Qualitative and Quantitative Evaluation on Various Roles of Root in Whole Crop Plant Physiology
| Project/Area Number |
05404008
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | Tokyo University of Agriculture and Technology |
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Principal Investigator |
ISHIHARA Kuni Tokyo University of Agriculture and Technology, Faculty of Agriculture, Professor, 農学部, 教授 (70014925)
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| Co-Investigator(Kenkyū-buntansha) |
OOKAWA Taiichiro Tokyo University of Agriculture and Technology, Faculty of Agriculture, Assistan, 農学部, 助手 (80213643)
HIRASAWA Tadashi Tokyo University of Agriculture and Technology, Faculty of Agriculture, Associat, 農学部, 助教授 (30015119)
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| Project Period (FY) |
1993 – 1996
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| Keywords | Cytokinin / Drought tolerance / Hydrotropism / Photosynthesis / Root system development / Salt tolerance / Senescence / Water uptake capacity |
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| Research Abstract |
Roots have various functions such as uptake of water and inorganic nutrients and synthesis of various compounds including plant hormones. They also show the various responses to environmental conditions. This research was conducted to evaluate the role of root in whole crop plant physiology. The results obtained are as follows.
(1) In soybeans, drought-tolerance is remarkable and the decrease in dry matter and grain production was small in the cultivars with developed expansive root systems. Mangrove trees growing in the sea water area along the coast could maintain their turgor because they could absorb ground water running out from the land.
(2) Root hydrotropism might occur after perception of a difference in water potential by the root tip. Roots could perceive the small gradient of water potential and bend hydrotropically in vermiculite.
(3) In the crop plants with well developed root systems and with roots of high physiological activity, root water uptake capacity was high and the midday and afternoon reduction in photosynthetic rate was small. And also the reduction in photosynthetic rate with age was small in these plants.
(4) Summer field crop plants in Japan would develop shoots but poor root systems during the rainy season called "Baiu". This would enlarge the adverse effects of soil moisture depletion on dry matter production under the deficient soil moisture conditions and would decrease the efficiency of the irrigated water-use in summer thereafter.
(5) Exudation rate was large and leaf senescence was slow during the ripening stage in rice plants cv. Akenohoshi compared with cv. Nipponbare. The larger amounts of cytokinins, in particular conjugated Zeatin, was transported from the roots to the shoots in the former than the latter.
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