1990 Fiscal Year Final Research Report Summary
A Study on the Geographical Differentiation of Ceratopteris Thalictroides Populations in Japan
| Project/Area Number |
63540552
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物形態・分類学
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| Research Institution | Tokyo Woman's Christian University |
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Principal Investigator |
MASUYAMA Shigeo Tokyo Woman's Christian Univ. Coll. of Culture and Communication Professor, 現代文化学部, 教授 (20101008)
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| Co-Investigator(Kenkyū-buntansha) |
WATANO Yasuyuki Kanazawa Univ. Fac. of Science Assistant, 理学部, 助手 (70192820)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Ceratopteris thalictroides / Geographical cline / Allozyme / Gametophytic selfing / Inbreeding / Annual / Polyploid |
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| Research Abstract |
The purpose of the present study is to settle the following problems as to the annual, polyploid fern Ceratopteris thalictroides (L.) Brongn. in Japan : (1) To what degree is this species varied in morphology among local populations in Japan? (2) What adaptive significance does the morphological variation among local populations possess? (3) What specific characteristics have played an important role to establish the morphological variation among local populations? (4) To what degree is the morphological variation among local populations linked with their genetic variation?
The followings were revealed and concluded in the investigation during three years.
As to (1) : A geographical cline is recognizable in the morphological variation among local populations. That is, plants are smaller and simpler in shape in the northern regions than in the southern regions.
As to (2) : The north type, which is characterized by a shorter period of the vegetative growth, is well adapted to the mode of rice cultivation in the north of Japan.
As to (3) : Because a local population showed a high rate of gametophytic selfing near to 0.9, inbreeding is probably predominant in this species. Specific characteristics of high inbreeding and annually colonizing may have promoted to establish the above north type in the northern regions.
As to (4) : Two types of the genetic variation are present in Japanese populations. One possesses the allozyme components suggesting the autopolyploid origin and the other has those suggesting allopolyploid origin. The former is distributed limitedly in the area on the south of Isl. Okinawa and the latter is widely distributed in the area on the north of that island.
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