| 1. |
- Jonsdottir, IS, et al.
(author)
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Genet age in marginal populations of two clonal Carex species in the Siberian Arctic
- 2000
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In: Ecography. - : Wiley. - 1600-0587 .- 0906-7590. ; 23:4, s. 402-412
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Journal article (peer-reviewed)abstract
- During a Swedish-Russian expedition to northern Siberia 1994, we sampled two marginal populations of two Carex species at two high arctic sites (C. stuns Drej. on Faddeyevsky Island and C. ensifolia V. Krecz ssp, arctisibirica Jurtz. at north-eastern Taymyr Peninsula), both north of previously documented localities in that areas for the two species. These populations were composed of a few distinct patches of ramet colonies, some of them shaped like fairy rings with dead centres. We measured the size of all colonies and collected samples for detailed morphometric analyses of rhizome growth. By using RAPD (random amplified polymorphic DNA) analysis we established that the largest colony at each site consisted of a single genet, based on 41 polymorphic bands amplified with three primers. Fouled samples from each of two additional colonies of C. stuns on Faddeyevsky Island were analysed and showed that clones of the same species at the same site were relatively dissimilar (Dice's similarity index 0.26-0.43). We then assumed that each ramet colony represented a single genet. Based on the morphometric data, we developed a deterministic growth model that simulates the clonal growth of these species and enabled estimates of the time since establishment of the genets. The estimated age of the five C. stans clones varied from 17 to 154 yr and the age of the two C. ensifolia ssp. arctisibirica clones was well over 3000 yr.
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| 2. |
- Stenstrom, A., et al.
(author)
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Genetic variation and clonal diversity in four clonal sedges (Carex) along the Arctic coast of Eurasia
- 2001
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In: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 10:2, s. 497-513
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Journal article (peer-reviewed)abstract
- We studied the structure of genetic variation (at both ramet- and genet-level) and clonal diversity within and among populations in the four closely related arctic clonal sedges Carex bigelowii, C. ensifolia, C. lugens and C. stans by use of allozyme markers. Compared to other sedges and arctic plants, the studied taxa all had high levels of genetic variation, both within populations and taxa. These taxa contained most of the total gene diversity (HT) within populations and a small part of the diversity among populations (GST ranged 0.05-0.43). Carex bigelowii had genetic variation (HS = 0.173, mean for populations) at a comparable level to other outbreeding arctic plants and to other widespread, rhizomatous and mainly outbreeding Carex species. In contrast, C. ensifolia (HS = 0.335), C. lugens (HS = 0.339) and C. stans (HS = 0.294) had within-population variations that were higher than in most other studied Carex species and for arctic plants in general. Genetic variation was not related to any tested environmental variable, but it was lower in areas deglaciated only 10 000 years BP compared to areas deglaciated 60 000 years BP or not glaciated at all during the Weichselian. All the populations were multiclonal, except for two populations of C. stans that were monoclonal. In contrast to genetic variation, clonal diversity decreased with latitude and did not differ between areas with different times of deglaciation. In accordance with previous studies, C. bigelowii and C. lugens were found to be outbreeding, while C. ensifolia and C. stans had mixed mating systems.
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| 3. |
- Stenström, A, et al.
(author)
-
Genetic variation and clonal diversity in four clonal sedges (Carex) along the Arctic coast of Eurasia
- 2001
-
In: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 10:2, s. 497-513
-
Journal article (peer-reviewed)abstract
- We studied the structure of genetic variation (at both ramet- and genet-level) and clonal diversity within and among populations in the four closely related arctic clonal sedges Carex bigelowii, C. ensifolia, C. lugens and C. starts by use of allozyme markers. Compared to other sedges and arctic plants, the studied taxa all had high levels of genetic variation, both within populations and taxa. These taxa contained most of the total gene diversity (H-T) within populations and a small part of the diversity among populations (G(ST) ranged 0.05-0.43). Carex bigelowii had genetic variation (H-S = 0.173, mean for populations) at a comparable level to other outbreeding arctic plants and to other widespread, rhizomatous and mainly outbreeding Carex species. In contrast, C. ensifolia (H-S = 0.335), C. lugens (H-S = 0.339) and C. stans (H-S = 0.294) had within-population variations that were higher than in most other studied Carex species and for arctic plants in general. Genetic variation was not related to any tested environmental variable, but it was lower in areas deglaciated only 10 000 years BP compared to areas deglaciated 60 000 years BP or not glaciated at all during the Weichselian. All the populations were multiclonal, except for two populations of C. starts that were monoclonal. In contrast to genetic variation, clonal diversity decreased with latitude and did not differ between areas with different times of deglaciation. In accordance with previous studies, C. bigelowii and C. lugens were found to be outbreeding, while C. ensifolia and C. stans had mixed mating systems.
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