アジアおよび北アメリカに分布する延齢草の進化遺伝学的研究
The wild flower Trillium, which belongs to Liliaceae, is widely distributed in the eastern part of Asia and the western and eastern parts of North America across the Pacific Ocean. In the Asian species a polyploid system develops in the pedicelled flower as a diploid, Trillium kamtschaticum, triploi...
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| Format: | Report |
| Language: | Japanese |
| Published: |
1968
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| Online Access: | https://twcu.repo.nii.ac.jp/?action=repository_uri&item_id=17671 http://id.nii.ac.jp/1632/00017665/ https://twcu.repo.nii.ac.jp/?action=repository_action_common_download&item_id=17671&item_no=1&attribute_id=22&file_no=1 |
| Summary: | The wild flower Trillium, which belongs to Liliaceae, is widely distributed in the eastern part of Asia and the western and eastern parts of North America across the Pacific Ocean. In the Asian species a polyploid system develops in the pedicelled flower as a diploid, Trillium kamtschaticum, triploids, Trillium Hagae and Trillium yezoense, tetraploids, Trillium Tschonoskii, Trillium apetalon and Trillium Miyabeanum, and hexaploids, Trillium Hagae and Trillium Smallii. It seems that the other spicies except the diploid species might have formed by interspecific hybrids between the species of a few strains. The Asian species are outbreeded easily by a structure of the floral organ. Typical example, an intergeneric hybrid Kinugasa japonica between the Trillium and Paris species, occurs in the central mountain region of the Japanese islands. On the other hand, all American species belong to only a diploid although there are a lot of species and variable morphological characters within and between species. Some plants of a species have supernumerary chromosomes. The American species consist of two groups; the pedicelled flower of mainly white flower strain and the sessiled flower of red purple and yellow strains. As a whole there is a complex phenomenon within species and between species in the American Trillium species. It seems likely that the origin of the Trillium species was located in the eastern part of North America because it abounds in species and their variations. In the Pliocene age, associated with the development of the forest of hardwoods, a few strains of Trillium species from North America might migrated and arrived to the eastern Asian region through the Bering-Chukchi Platform. In the Pleistocene the glaciations covered the northern area (Nebraskan, Kansan, Illinoian and Wisconsin glaciations) and the isolations between Asia and North America occured. In the Japanese islands there was no glaciation because of the influence of a warm sea current. In the Japanese Trillium species, which started fro m a few strains in North American species, the polyploid system was accelerated by volcanic activities and crossings frequently after the glaciation age. |
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