Systematics of polyploid Dactylorhiza (Orchidaceae) - genetic diversity, phylogeography and evolution
(2008)- Abstract
- This thesis examines genetic variation in allotetraploids of the Dactylorhiza incarnata/maculata polyploid complex in different parts of Europe. The molecular markers used were AFLPs, allozymes, ITS, nuclear microsatellites and plastid DNA markers.
The results showed that the Alps and Greece have served as refugia for the genus during Pleistocene glaciations. Immigration routes of D. majalis ssp. lapponica into Fennoscandia after the last ice age were described. One wave of immigration reached Scandinavia from the south and one from northeast via Finland. Gotland was recolonized from the east. A meeting zone was detected in northern Scandinavia.
No genetic markers could clearly divide the allotetraploids of the complex... (More) - This thesis examines genetic variation in allotetraploids of the Dactylorhiza incarnata/maculata polyploid complex in different parts of Europe. The molecular markers used were AFLPs, allozymes, ITS, nuclear microsatellites and plastid DNA markers.
The results showed that the Alps and Greece have served as refugia for the genus during Pleistocene glaciations. Immigration routes of D. majalis ssp. lapponica into Fennoscandia after the last ice age were described. One wave of immigration reached Scandinavia from the south and one from northeast via Finland. Gotland was recolonized from the east. A meeting zone was detected in northern Scandinavia.
No genetic markers could clearly divide the allotetraploids of the complex into groups according to their current taxonomy. All allotetraploid derivatives should be considered as subspecies of D. majalis. Further, no markers separated the morphologically confluent “traunsteineri”, “lapponica” and “russowii”, and they were accordingly combined as: D. majalis ssp. lapponica. Greek allotetraploids should be treated as regional or local variants of D. majalis ssp. cordigera.
The levels of genetic diversity in the allopolyploids were as high as in the diploids. In addition, unique alleles and haplotypes were found among the polyploids.
Allotetraploid Dactylorhiza includes lineages retained from both old and new polyploidization events. Introgression involving both parental lineages was detected, as well as recent and old hybridizations between polyploid lineages. Finally, evidence of diploidization in the allotetraploids in terms of intergenomic recombination and gene conversion was found. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1274875
- author
- Olofsson, Sofie LU
- supervisor
- opponent
-
- Hollingsworth, Peter, Royal Botanic Garden Edinburgh
- organization
- publishing date
- 2008
- type
- Thesis
- publication status
- published
- subject
- keywords
- microsatellites, allozymes, ITS, plastid DNA, Dactylorhiza majalis ssp. traunsteineri, allopolyploidy, AFLPs, immigration history, diploidization, hybridization
- pages
- 155 pages
- defense location
- Blå Hallen, Ekologihuset
- defense date
- 2009-01-30 10:00:00
- ISBN
- 978-91-7105-286-5
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Plant Ecology and Systematics (Closed 2011) (011004000)
- id
- 1ce1ef67-63a4-48d0-a81b-36d90f3efd20 (old id 1274875)
- date added to LUP
- 2016-04-04 13:57:42
- date last changed
- 2023-04-26 07:52:56
@phdthesis{1ce1ef67-63a4-48d0-a81b-36d90f3efd20,
abstract = {{This thesis examines genetic variation in allotetraploids of the Dactylorhiza incarnata/maculata polyploid complex in different parts of Europe. The molecular markers used were AFLPs, allozymes, ITS, nuclear microsatellites and plastid DNA markers. <br/><br>
The results showed that the Alps and Greece have served as refugia for the genus during Pleistocene glaciations. Immigration routes of D. majalis ssp. lapponica into Fennoscandia after the last ice age were described. One wave of immigration reached Scandinavia from the south and one from northeast via Finland. Gotland was recolonized from the east. A meeting zone was detected in northern Scandinavia. <br/><br>
No genetic markers could clearly divide the allotetraploids of the complex into groups according to their current taxonomy. All allotetraploid derivatives should be considered as subspecies of D. majalis. Further, no markers separated the morphologically confluent “traunsteineri”, “lapponica” and “russowii”, and they were accordingly combined as: D. majalis ssp. lapponica. Greek allotetraploids should be treated as regional or local variants of D. majalis ssp. cordigera.<br/><br>
The levels of genetic diversity in the allopolyploids were as high as in the diploids. In addition, unique alleles and haplotypes were found among the polyploids. <br/><br>
Allotetraploid Dactylorhiza includes lineages retained from both old and new polyploidization events. Introgression involving both parental lineages was detected, as well as recent and old hybridizations between polyploid lineages. Finally, evidence of diploidization in the allotetraploids in terms of intergenomic recombination and gene conversion was found.}},
author = {{Olofsson, Sofie}},
isbn = {{978-91-7105-286-5}},
keywords = {{microsatellites; allozymes; ITS; plastid DNA; Dactylorhiza majalis ssp. traunsteineri; allopolyploidy; AFLPs; immigration history; diploidization; hybridization}},
language = {{eng}},
school = {{Lund University}},
title = {{Systematics of polyploid Dactylorhiza (Orchidaceae) - genetic diversity, phylogeography and evolution}},
year = {{2008}},
}