1999 Fiscal Year Final Research Report Summary
Aneuploidy and genetic differentiation in Carex pisiformis-complex (Cyperaceae)
| Project/Area Number |
09640830
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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 |
系統・分類
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| Research Institution | Okayama University of Science |
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Principal Investigator |
HOSHINO Takuji Okayama University of Science, Faculty of Informatics, Professor, 総合情報学部, 教授 (10122392)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Cyperaceae / Carex / Carex pisiformis-complex / Taxonomic revision / Chromosome / Aneuploidy / Allozyme variation / Genetic differentiation |
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| Research Abstract |
Carex pisiformis-complex is one of the most taxonomically difficult groups in the genus Carex. The aim of this study is to revise the taxonomic treatment and describe the meiotic chromosome behavior of Carex pisiformis-complex. To assess genetic relationships among taxa, 40 populations were used for isozyme analysis.
1. Taxonomic revision
The specimens collected from Hokkaido Prefecture, were distinguished from C. sachalinensis var. alterniflora (French.) Ohwi by short culm and pale brownish sheaths. A new taxon collected from western Japan was easily distinguished from C. fernaldiana and C. hakonemontanae by narrow and rolled leaves. Fifteen species and eleven varieties were recognized by morphological studies of C. pisiforms complex.
2. Cytological observation
Chromosome number and configurations at meiotic metaphase were determined for seven taxa of C. pisiformis-complex. Consecutive chromosome numbers were observed in five taxa. At meiotic metaphase, every trivalent was heteromorphic chain configurations. These results indicate the aneuploid series originated primarily from chromosome mutation and, subsequently, maintained aneuploidy within each population by self/or cross-fertilization.
3. Allozyme variation
Forty populations in the complex were examined utilizing polyacrylamide gel electrophoresis and thirteen interpretable loci were scored for ten enzyme system. Gene duplications were found in four taxa. Neighbor joining phenogram shows these four taxa are clustered together and derived from ancestors with 2n=56-61 through increasing in chromosome number.
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