| Project/Area Number |
09839020
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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 |
自然史科学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
TACHIDA Hidenori Kyushu University, Faculty of Science, Associate Professor, 理学部, 助教授 (70216985)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAZAKI Tsuneyuki Kyushu University, Faculty of Science, Professor, 理学部, 教授 (10108649)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1998: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1997: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | tropical rain forests / genetic diversity / GapC gene / Dipterocarpaceae / nucleotide diversity / the neutrality test / the nearly neutral model / molecular population genetics / 地理的構造 / 平均適応度 |
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| Research Abstract |
In order to clarify how genetic diversity relates to species diversity found in Asian Dipterocarpaceae trees that comprise important components of tropical rain forests, we estimated DNA variation between and within species in the family. First, we determined the relationships among genera within the family by sequencing chioroplast DNA.The Asian family members were shown to be divided into two groups and the genus Shorea was found to include a few other genera. Next we determined genetic diversity between and within four species in Shorea, S.leprosula, S.acuminata, S.curtisii and S.parvifolia by direct sequencing. Although we could not detect any variation in a chloroplast DNA region, the nucleotide diversity in the partial GapC (nuclear) gene was found to be between 0.00 12 and 0.0029 per site in the four species. The divergence between species was between 0.00781 and 0.01621 . The selfing rate was estimated to be between 0.39 and 0.67.
To understand evolutionary implications of sequence data in relation to selection, we analyzed the nearly neutral mutation model theoretically. First, changes of population size were shown to increase the dispersion index, an index measuring variability of evolutionary rates, under this model. Next, the powers of detecting selection using several tests of the neutrality including Tajimas test and the MK test were investigated assuming a multisite nearly neutral model. The analysis showed the importance of discriminating replacement and silent variation for detecting this type of selection. We could not detect selection from our GapC data but this may be due to very little replacement variation in this gene. We need to survey more gene regions to clarify genetic diversity and its meaning for species diversity in this family
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