Cargando…

Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)

BACKGROUND: Recent studies highlighted the role of Pleistocene climatic cycles in polyploid speciation and of southern Alpine refugia as reservoirs of diversity during glacial maxima. The polyploid Primula marginata, endemic to the southwestern Alps, includes both hexaploid and dodecaploid cytotypes...

Descripción completa

Detalles Bibliográficos
Autores principales: Casazza, Gabriele, Granato, Laura, Minuto, Luigi, Conti, Elena
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3444416/
https://www.ncbi.nlm.nih.gov/pubmed/22530870
http://dx.doi.org/10.1186/1471-2148-12-56
_version_ 1782243681596604416
author Casazza, Gabriele
Granato, Laura
Minuto, Luigi
Conti, Elena
author_facet Casazza, Gabriele
Granato, Laura
Minuto, Luigi
Conti, Elena
author_sort Casazza, Gabriele
collection PubMed
description BACKGROUND: Recent studies highlighted the role of Pleistocene climatic cycles in polyploid speciation and of southern Alpine refugia as reservoirs of diversity during glacial maxima. The polyploid Primula marginata, endemic to the southwestern Alps, includes both hexaploid and dodecaploid cytotypes that show no ecological or morphological differences. We used flow cytometry to determine variation and geographic distribution of cytotypes within and between populations and analyses of chloroplast (cp) and nuclear ribosomal (nr) DNA sequences from the Internal Transcribed Spacer (ITS) region to infer the evolutionary history of the two cytotypes and the auto- vs. allopolyploid origin of dodecaploid populations. RESULTS: We did not detect any intermediate cytotypes or variation of ploidy levels within populations. Hexaploids occur in the western and dodecaploids in the eastern part of the distributional range, respectively. The cpDNA and nrDNA topologies are in conflict, for the former supports shared ancestry between P. marginata and P. latifolia, while the latter implies common origins between at least some ITS clones of P. marginata and P. allionii. CONCLUSIONS: Our results suggest an initial episode of chloroplast capture involving ancestral lineages of P. latifolia and P. marginata, followed by polyploidization between P. marginata-like and P. allionii-like lineages in a southern refugium of the Maritime Alps. The higher proportion of ITS polymorphisms in dodecaploid than in hexaploid accessions of P. marginata and higher total nucleotide diversity of ITS clones in dodecaploid vs. hexaploid individuals sequences are congruent with the allopolyploid hypothesis of dodecaploid origin.
format Online
Article
Text
id pubmed-3444416
institution National Center for Biotechnology Information
language English
publishDate 2012
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-34444162012-09-18 Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae) Casazza, Gabriele Granato, Laura Minuto, Luigi Conti, Elena BMC Evol Biol Research Article BACKGROUND: Recent studies highlighted the role of Pleistocene climatic cycles in polyploid speciation and of southern Alpine refugia as reservoirs of diversity during glacial maxima. The polyploid Primula marginata, endemic to the southwestern Alps, includes both hexaploid and dodecaploid cytotypes that show no ecological or morphological differences. We used flow cytometry to determine variation and geographic distribution of cytotypes within and between populations and analyses of chloroplast (cp) and nuclear ribosomal (nr) DNA sequences from the Internal Transcribed Spacer (ITS) region to infer the evolutionary history of the two cytotypes and the auto- vs. allopolyploid origin of dodecaploid populations. RESULTS: We did not detect any intermediate cytotypes or variation of ploidy levels within populations. Hexaploids occur in the western and dodecaploids in the eastern part of the distributional range, respectively. The cpDNA and nrDNA topologies are in conflict, for the former supports shared ancestry between P. marginata and P. latifolia, while the latter implies common origins between at least some ITS clones of P. marginata and P. allionii. CONCLUSIONS: Our results suggest an initial episode of chloroplast capture involving ancestral lineages of P. latifolia and P. marginata, followed by polyploidization between P. marginata-like and P. allionii-like lineages in a southern refugium of the Maritime Alps. The higher proportion of ITS polymorphisms in dodecaploid than in hexaploid accessions of P. marginata and higher total nucleotide diversity of ITS clones in dodecaploid vs. hexaploid individuals sequences are congruent with the allopolyploid hypothesis of dodecaploid origin. BioMed Central 2012-04-24 /pmc/articles/PMC3444416/ /pubmed/22530870 http://dx.doi.org/10.1186/1471-2148-12-56 Text en Copyright ©2012 Casazza et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Casazza, Gabriele
Granato, Laura
Minuto, Luigi
Conti, Elena
Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)
title Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)
title_full Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)
title_fullStr Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)
title_full_unstemmed Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)
title_short Polyploid evolution and Pleistocene glacial cycles: A case study from the alpine primrose Primula marginata (Primulaceae)
title_sort polyploid evolution and pleistocene glacial cycles: a case study from the alpine primrose primula marginata (primulaceae)
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3444416/
https://www.ncbi.nlm.nih.gov/pubmed/22530870
http://dx.doi.org/10.1186/1471-2148-12-56
work_keys_str_mv AT casazzagabriele polyploidevolutionandpleistoceneglacialcyclesacasestudyfromthealpineprimroseprimulamarginataprimulaceae
AT granatolaura polyploidevolutionandpleistoceneglacialcyclesacasestudyfromthealpineprimroseprimulamarginataprimulaceae
AT minutoluigi polyploidevolutionandpleistoceneglacialcyclesacasestudyfromthealpineprimroseprimulamarginataprimulaceae
AT contielena polyploidevolutionandpleistoceneglacialcyclesacasestudyfromthealpineprimroseprimulamarginataprimulaceae