Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland
BACKGROUND AND AIMS: The island of Gotland in the Baltic Sea has had no contact with surrounding continental areas since the withdrawal of the Weichselian ice sheet at approx. 17 ka BP. Plants present on Gotland must have arrived by long-distance dispersal, so populations are expected to exhibit red...
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ftpubmed:oai:pubmedcentral.nih.gov:6266126 2023-05-15T16:41:18+02:00 Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland Hedrén, Mikael Olofsson, Sofie Nordström Paun, Ovidiu 2018-11 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266126/ http://www.ncbi.nlm.nih.gov/pubmed/29955767 https://doi.org/10.1093/aob/mcy111 en eng Oxford University Press http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266126/ http://www.ncbi.nlm.nih.gov/pubmed/29955767 http://dx.doi.org/10.1093/aob/mcy111 © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) Original Articles Text 2018 ftpubmed https://doi.org/10.1093/aob/mcy111 2019-11-03T01:19:23Z BACKGROUND AND AIMS: The island of Gotland in the Baltic Sea has had no contact with surrounding continental areas since the withdrawal of the Weichselian ice sheet at approx. 17 ka BP. Plants present on Gotland must have arrived by long-distance dispersal, so populations are expected to exhibit reduced levels of genetic diversity compared with populations on surrounding mainlands. However, orchids have very small seeds, which appear well adapted to long-distance dispersal, and they should therefore be less affected than other plant species by colonization bottlenecks. The aim of this study was to analyse the genetic structure of orchids colonizing isolated islands, using the marsh orchid Dactylorhiza majalis ssp. lapponica as a case study. METHODS: More than 500 samples from 27 populations were analysed for 15 plastid and eight nuclear marker loci. Population diversity and differentiation patterns were compared for nuclear and plastid marker systems and analysed in relation to geographical location. KEY RESULTS: We found high genetic diversity but no clear geographical structure of genetic differentiation between populations on Gotland. However, the between-population differentiation in plastid and nuclear markers were correlated and the greatest diversity was found at sites at comparatively high elevations, which were the first to emerge above the water after the Ice Age. CONCLUSIONS: The regional population on Gotland has been established by a minimum of four dispersal events from continental regions. Subsequent gene flow between sites has not yet homogenized the differentiation pattern originating from initial colonization. We conclude that long-distance seed dispersal in orchids has a strong impact on structuring genetic diversity during periods of expansion and colonization, but contributes less to gene flow between populations once a stable population structure has been achieved. Text Ice Sheet PubMed Central (PMC) Annals of Botany |
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Original Articles Hedrén, Mikael Olofsson, Sofie Nordström Paun, Ovidiu Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland |
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Original Articles |
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BACKGROUND AND AIMS: The island of Gotland in the Baltic Sea has had no contact with surrounding continental areas since the withdrawal of the Weichselian ice sheet at approx. 17 ka BP. Plants present on Gotland must have arrived by long-distance dispersal, so populations are expected to exhibit reduced levels of genetic diversity compared with populations on surrounding mainlands. However, orchids have very small seeds, which appear well adapted to long-distance dispersal, and they should therefore be less affected than other plant species by colonization bottlenecks. The aim of this study was to analyse the genetic structure of orchids colonizing isolated islands, using the marsh orchid Dactylorhiza majalis ssp. lapponica as a case study. METHODS: More than 500 samples from 27 populations were analysed for 15 plastid and eight nuclear marker loci. Population diversity and differentiation patterns were compared for nuclear and plastid marker systems and analysed in relation to geographical location. KEY RESULTS: We found high genetic diversity but no clear geographical structure of genetic differentiation between populations on Gotland. However, the between-population differentiation in plastid and nuclear markers were correlated and the greatest diversity was found at sites at comparatively high elevations, which were the first to emerge above the water after the Ice Age. CONCLUSIONS: The regional population on Gotland has been established by a minimum of four dispersal events from continental regions. Subsequent gene flow between sites has not yet homogenized the differentiation pattern originating from initial colonization. We conclude that long-distance seed dispersal in orchids has a strong impact on structuring genetic diversity during periods of expansion and colonization, but contributes less to gene flow between populations once a stable population structure has been achieved. |
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Text |
author |
Hedrén, Mikael Olofsson, Sofie Nordström Paun, Ovidiu |
author_facet |
Hedrén, Mikael Olofsson, Sofie Nordström Paun, Ovidiu |
author_sort |
Hedrén, Mikael |
title |
Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland |
title_short |
Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland |
title_full |
Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland |
title_fullStr |
Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland |
title_full_unstemmed |
Orchid colonization: multiple parallel dispersal events and mosaic genetic structure in Dactylorhiza majalis ssp. lapponica on the Baltic island of Gotland |
title_sort |
orchid colonization: multiple parallel dispersal events and mosaic genetic structure in dactylorhiza majalis ssp. lapponica on the baltic island of gotland |
publisher |
Oxford University Press |
publishDate |
2018 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266126/ http://www.ncbi.nlm.nih.gov/pubmed/29955767 https://doi.org/10.1093/aob/mcy111 |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266126/ http://www.ncbi.nlm.nih.gov/pubmed/29955767 http://dx.doi.org/10.1093/aob/mcy111 |
op_rights |
© The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) |
op_doi |
https://doi.org/10.1093/aob/mcy111 |
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Annals of Botany |
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1766031737715949568 |