1991 Fiscal Year Final Research Report Summary
Phylogenetic and evolutionary studies of rheophytes in the everwet tropics
| Project/Area Number |
01041024
|
|---|
| Research Category |
Grant-in-Aid for international Scientific Research
|
| Allocation Type | Single-year Grants |
|---|
| Section | Field Research |
|---|
| Research Institution | University of Tokyo |
|---|
Principal Investigator |
KATO Masahiro Associate Prof., Fac. of Science, Univ. of Tokyo, 理学部, 助教授 (20093221)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
DARNAEDI Dedy Research staff, Herbarium Bogoriense, Indonesia, 研究員
SOEDARSONO R ボゴール植物標本館, 館長
OKADA Hiroshi Lecturer, Coll. of General Arts and Sciences, Osaka Univ., 教養部, 講師 (40089892)
WATANO Yasuyuki Research Associate, Fac. of Science, Kanazawa Univ., 理学部, 助手 (70192820)
SAKAMAKI Yoshiaki Staff member, Waseda University, 所沢キャンパス自然環境調査室, 常勤嘱託
IMAICHI Ryoko Associate Prof., Fac. of Agriculture, Tamaga Univ., 農学部, 助教授 (60112752)
MURATA Jin Lecturer, Fac. of Science, Univ. of Tokyo, 理学部, 講師 (90134452)
RISWAN Soedarsono Director, Herbarium Bogoriense, Indonesia
|
|---|
| Project Period (FY) |
1989 – 1991
|
| Keywords | adaptation / development / diversity / Kalimantan / morphological evolution / phylogeny / rheophyte / tropics |
|---|
| Research Abstract |
1. About 60 species of fern rheophytes collected or recorded from Bomeo are much more than 12 species van Steenis recorded in 1981 and approach 82 angiosperm species recorded from there. It indicates much greater diversity of the fern rheophytes of Borneo than understood at present.
2. Rheophytic bryophytes can be characterized as : leaves multi-layered ; stems tough, often creeping ; plants low in height ; stem-branching sympodial and plants matted. In these characters, rheophytic bryophytes (gametophytes) resemble the sporophytes of vascular rheophytes rather than the gametophytes.
3. Comparative leaf anatomical study of tropical rheophytes and related dry-land species shows that rheophytic stenophylly is due partly to less expanded, short-armed mesophyll cells and consequent smaller-spaced intercellular spaces than broad leaves of dryland species.
4. Leaf developmental study of a rheophyte and related dry-land species to examine how rheophytic stenophylls are formed during ontogeny. At
… More
an early stage the primordia of the rheophytic stenophylls are smaller than those of dry-land broad leaves. During the cell-expansion stage the stenophylls cease to expand earlier than the dry-land leaves, presumably due to heterochrony(paedomorphosis). Smaller intercellular spaces of the stenophyll result lower photosynthetic rate, which is assumed to make the rheophytes difficult to grow in terrestrial habitat in which photosynthetically more active dry-land species grow.
5. Molecular systematic study shows that the rheophytic Osmunda lancea is more closely related to the terrestrial O. japonica (eastern Asia) than to the terrestrial O. regalls (North America, Europe etc.), although the last two morphologically resemble one another. The result confirms that the rheophyte is derived from the dry-land species.
6. Developmental study of gametophytes of the rheophytic Osmunda lancea and the terrestrial O. japonica shows that there is no marked difference in gametophyte morphology but the rheophytic gametophytes grow faster to produce more sporophytes earlier than the dry-land ones, and that O. lancea takes generation-specific adaptive strategy. Less
|
Research Products
(11 results)
