| 研究課題/領域番号 |
23K05916
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| 研究種目 |
基盤研究(C)
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| 配分区分 | 基金 |
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| 応募区分 | 一般 |
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| 審査区分 |
小区分45040:生態学および環境学関連
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| 研究機関 | 筑波大学 |
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研究代表者 |
Irving Louis 筑波大学, 生命環境系, 助教 (60597178)
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| 研究期間 (年度) |
2023-04-01 – 2026-03-31
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| 研究課題ステータス |
交付 (2023年度)
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| 配分額 *注記 |
4,290千円 (直接経費: 3,300千円、間接経費: 990千円)
2025年度: 650千円 (直接経費: 500千円、間接経費: 150千円)
2024年度: 1,300千円 (直接経費: 1,000千円、間接経費: 300千円)
2023年度: 2,340千円 (直接経費: 1,800千円、間接経費: 540千円)
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| キーワード | Orobanche / parasite / nitrogen / carbon / isotope / parasitic plant / legume / rhizobia / C/N balance / N-fixation |
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| 研究開始時の研究の概要 |
This research explores the influence of environmental and spatial factors on the relationships between the holoparasitic plant Orobanche minor, N-fixation, and the performance of the red clover host.
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| 研究実績の概要 |
I completed the first phase of the research and am preparing a manuscript for publication in a high-impact journal. Host growth and nutrient uptake were severely limited where nutrients were supplied to parasitized roots. I have started three new direction, 1) effect of N level and parasitism on host photosynthesis, 2) effect of parasite / rhizobia position on the host-parasite relationship, 3) developing a clean system for host - parasite isotope tracing studies.
For 1, we found that N supply leads to a strong suppression in both parasite establishment and parasite growth. However, low level N supply caused a decline in photosynthetic rates.
For 2, we found that parasite mass was strongly increased when grown near the bottom of the root box, although the mechanism is unknown. We have developed two plausible hypotheses, either that the parasite is directly taking nutrients up from the surrounding media, or that N fixed in the upper part of the root is being transported to the parasite.
For 3, we have established a system, although parasite necrosis is an issue. In the next few months we will develop an isotope labelling system for 13CO2 in order to quantify host to parasite carbon flux kinetics.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
There are no issues with the project, although it is generating many surprising results which require some reevaluation of the original plan.
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| 今後の研究の推進方策 |
This summer I will measure the effect of parasite number of host photosynthesis (low vs. high rate of parasitism) in collaboration with Dr. Shinya Wada (Tohoku UNiv). We will also try time-series 13C labeling to investigate host --> parasite C transfer kinetics, and the effect of environmental conditions. I will evaluate nutrient uptake and parasite capture of nutrients supplied above or below the point of attachment.
It was unexpectedly difficult to do spatial analysis of parasite / rhizobia interactions, because the rhizobia could not be contained in one part of the root system. I will improve my root box design and improve rhizobia-handling procedures to counter these issues.
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