1990 Fiscal Year Final Research Report Summary
Comparative study of pohioglossoid leaves and angiosperm carpels
| Project/Area Number |
01540575
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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 | University of Tokyo |
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Principal Investigator |
KATO Masahiro Faculty of Science, University of Tokyo Associate Professor, 理学部, 助教授 (20093221)
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| Project Period (FY) |
1989 – 1990
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| Keywords | angiosperm / progymnosperm / Ophioglossaceae / carpel / ovule / leaf hyponasty / secondary vascular tissue / pedomorphosis |
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| Research Abstract |
1. In order to clarify the anatomical nature of the anomalous vascular tissue of Helminthostachys leylanica, a comparative study was made in branched rhizomes with destroyed shoot Spices. In a portion below the shoot apex to an insertion position of a lateral branch, there are parenchymatous cells and tracheary elements which are radially arranged outside of the primary xylem. These tissue is suggested to be comparable to the secondary vascular tissue of Botrychium and be produced from meristematic cells which appear temporarily in relation to destruction of shoot apices and formation of lateral branches. This evidence supports the idea that the Ophioglossaceae is a living progymnosperm.
2. The origin of angiosperm carpels was examined by comparing them to ophioglossoid fertile leaves. The two organs are similar in the three dimensional architecture, i. e. ovules and sporophores on the adaxial side of carpellary walls and trophores, respectively. Developmental anatomical evidence of ovules accumulated so far suggests that the development of ovules are equivalent to that of leaves. I proposed the Ophioglossoid model in which the angiosperm carpel was derived by pedomorphosis from a three-dimensional leafy organ like ophioglossoid fertile leaves and ovular anatropy is comparable to leaf hyponasty. In this model the fundamental architecture of the carpel had been established prior to carpel enclosure.
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