2002 Fiscal Year Final Research Report Summary
Evaluaation of gene flow and reproduction cost in a tree population
| Project/Area Number |
12660138
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学
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| Research Institution | Shimane University |
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Principal Investigator |
KAWAGUCHI Hideyuki Shimane University, Faculty of Life and Environmental Science, Associate Professor, 生物資源科学部, 助教授 (40202030)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Population / Aesculus turbinata / Reproduction / Pollen flow / Genetic structure / Seed dispersal / Seed production / Microsatellite |
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| Research Abstract |
The Japanese horse chestnut, Aesculus turbinata, is a tall deciduous tree species growing in cool temperate riparian forests in Japan. A. turbinata is andromonoecious and pollinated by mainly bumblebees. A. turbinata has large seeds which are dispersed by small mammals. A. turbinata occurs in riparian terrace and the lower part of slopes and often shows a linear-shaped distribution along a stream. Pollen flow, secondary seed dispersal, reproductive efforts, and genetic structure were analyzed in a linear-shaped population of A. turbinata along an upper narrow part of a stream. Six microsatellite makers were used for genetic analyses. Reproductive individuals of A. turbinata occurred about 1000m along the stream were sampled and analyzed as potential pollen donors. Seeds were collected from several individuals and their pollen donors were determined by microsatelite analyses. The number of pollen flow significantly decreased with increasing pollination distance. The amount of flowers and the timing of flowering in pollen donors were less effective on the number of pollen flow than the pollination distance. Fallen seeds were dispersed around mother tree by small mammals. Genetic similarity calculated from microsatellite analyses significantly decreased with increasing distance between individuals. The distance-dependent pollination and secondary seed dispersal around a mother tree may result in the spatial genetic structure in the A. turbinata population along the stream.
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