| Project/Area Number |
60540443
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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 Ass. Prof., Faculty of Science, University of Tokyo, 理学部, 助教授 (20093221)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Dryopteris sparsa complex / Agamosprous species / Hybrid / Adventitious bud / Vegetative reproduction / Origin / 類縁 |
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| Research Abstract |
Reticulate evolution is one of representative evolutionary patterns as well as divergent evolution. In the pattern species are derived from sterile hybrids by aquisition of agamosporous reproduction or polyploidization. The relationship and origin of agamosporous species was examined with special reference to reproduction mode. Anatomical study shows some unique morphological and anatomical features of buds in Dryopteris sparsa complex. One of them is development of the buds accompanized by dedifferentiation of parenchymatous cells below them and establishment of apical meristem with an apical cell partly derived from some of them. Another is the occurrence of the buds in a pair at the adaxial-lateral side of abortive leaves similar to the site of pinna attachment on normal leaves. D. sabaei and D. yakusilvicola bear the buds, while D. hayatae and D. sparsa lack them. The species-specificity and unique morphology of the buds support the relationship that the agamosporous D. yakusilvicola has been derived by hybridization between D. sabaei and D. sparsa. Hybrids between the two species bear the same buds but a hybrid between D. hayatae and D. sparsa lack them. The buds function as a form of vegetative reproduction. Persistency of the vegetatively reproducing hybrids, which can be considered as precursors of D. yakusilvicola, may be involved in the origin of this polymorphic agamosporous species.
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