| Project/Area Number |
16510177
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Resource conservation science
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| Research Institution | Tokyo Gakugei University |
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Principal Investigator |
OGAWA Kiyoshi Tokyo Gakugei University, Dep.Education, Associate Professor, 教育学部, 助教授 (70133113)
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| Co-Investigator(Kenkyū-buntansha) |
MORITA Tatsuyoshi Niigata Univ., Dep.Education and Human Science, Professor, 教育人間科学部, 教授 (30115084)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2004: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Dandelions (Taraxacum) / Hybridization / Introduced species / Population behavior / Ploidy level / 移入種 / 実生 / 生残 / 個体群 / 雑種 / 3倍体雑種 / 4倍体雑種 / 発芽温度 / クローン |
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| Research Abstract |
1. The following facts turned out about the artificial pure introduced dandelion population in the Tokyo Bay shore.
(1) The seedlings of the early summer birth were annihilated, and there were some surviving ones of the autumn birth.
(2) Being compared with the estimated value by the photograph of 2002, the decrease of the density of the dandelions was admitted in the order of 1/100 on the east side slope though an increase was done on the north side slope.
(3) The pure introduced species had wide range of germinating temperature, and did not have seed dormancy. In the tetraploid crossbreed, similar characteristics were seen, though some inhibition of seed germination by the high temperature was seen like in the native species.
(4) The viability loss of buried seeds in soil was remarkable in the introduced species and the tetraploid crossbreed, though the survival value of the seeds was excellent in the native dandelion in experiment until autumn.
(5) From the size comparison of the pollen in the population, the plants with a comparatively uniform diameter and the ones with various sizes were identified.
(6) As for the ploidy ratio of the introduction population, the pure introduced triploid was detected 85% and the diploid was done 15%. It was the remarkable difference of the ploidy composition in comparison with the populations in Tokyo, having higher ratio of triploid crossbreed than that of the pure introduced plants.
2. The frequency of the pure introduced species was higher than that of the crossbreed in Tohoku and the Hokkaido region. On the other hand, the advancement of the crossbreed was confirmed at the mountain aria in Central mainland of Japan, which was similarly the cold district as the regions mentioned above.
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