2003 Fiscal Year Final Research Report Summary
Integrated Study on Evolution of genus Nicotiana (Solanaceae)
| Project/Area Number |
13575009
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
系統・分類
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
ITO Motomi The University of Tokyo, Graduate School of Arts and Sciences, Associate Professor, 大学院・総合文化研究科, 助教授 (00193524)
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| Co-Investigator(Kenkyū-buntansha) |
HASEBE Mitsuyasu National Institute of Basic Biology, Professor, 教授 (40237996)
KITA Yoko The University of Tokyo, Graduate School of Science, Research Assistant, 大学院・理学系研究科, 助手 (60345262)
AOKI Seishiro The University of Tokyo, Graduate School of Arts and Sciences, Research Assistant, 大学院・総合文化研究科, 助手 (10334301)
ASAKAWA Takeshi Chiba University, Faculty of Science, Research Assistant, 理学部, 助手 (50213682)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Nicotiana / Southern Hemisphere / Gondowana / Molecular phylogeny / Phytogeography / systematics / Amphi-diploid / new species |
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| Research Abstract |
In this project of the study of taxonomy and biogeography, we have challenged a new approach. Thus far, studies of these fields usually treated many taxa of plants at once, while we focused on a representative group of plants and analyzed the evolutionary mechanism of division of speciation and the change of the distribution. We chose the wild-type plants of the genus Nicotiana as the object of our new approach. The genus Nicotiana belongs to Solanaceae and contains about 70 species. The natural distribution of Nicotiana is limited to Southern Hemisphere. 37 species of this genus occur in South America, 20 species in Australia, and a species in Africa. We investigated wild-type species of the genus Nicotiana in Bolivia and Argentina in South America and Australia, New Caledonia, and New Zealand in Oceania. First, as the result of taxonomy we discovered a novel species of the genus Nicotiana in South America. We analyze this plant using molecular phylogenetic and physiological methods. Secondly, we analyzed the change of distribution of some ten species of this genus using the biogeographical method. The result of this analysis is that at least two species, Nicotiana acaulis and N.Ikawakamii has been on the verge of extinction. Thirdly, we have obtained the phylogenetic results that show the origin of tobacco plants (Nicotiana tabacum). N.tabacum is thought to be amphidiploid plants. Although many studies exhibited that the maternal species of N.tabacum is N.sylvestris, the paternal species is unknown. Our analysis indicated that the plants of the paternal species might have been extinct. Research has still been attached to the start just. The further analysis is required in order to confirm these results.
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