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Evolutionary Processes and Hybridization within the Peat Mosses, Sphagnum

Natcheva, Rayna LU (2006)
Abstract
The aim of this thesis was to reveal details of the interspecific hybridization among bryophytes as exemplified by Sphagnum capillifolium and S. quinquefarium. I used a combination of morphometric and molecular methods, and cultivation experiments to (1) identify hybrid gametophytes, (2) reveal the contribution of each of the parents to the genomes of hybrids, (3) study the fertility of primary hybrid sporophytes, (4) explore the fitness of hybrids as compared to their parents. The results showed that S. capillifolium and S. quinquefarium are morphologically and genetically well differentiated. Hybrid sporophytes had low fertility. However, when the two species grow sympatrically, hybrid individuals are often present. They are... (More)
The aim of this thesis was to reveal details of the interspecific hybridization among bryophytes as exemplified by Sphagnum capillifolium and S. quinquefarium. I used a combination of morphometric and molecular methods, and cultivation experiments to (1) identify hybrid gametophytes, (2) reveal the contribution of each of the parents to the genomes of hybrids, (3) study the fertility of primary hybrid sporophytes, (4) explore the fitness of hybrids as compared to their parents. The results showed that S. capillifolium and S. quinquefarium are morphologically and genetically well differentiated. Hybrid sporophytes had low fertility. However, when the two species grow sympatrically, hybrid individuals are often present. They are morphologically and genetically more similar to S. capillifolium but possess a restricted number of traits and molecular markers of S. quinquefarium. A comparison with the genetic composition of hybrid gametophytes raised from primary hybrid sporophytes indicated that the natural hybrid gametophytes may be first generation recombinants. The inheritance of chloroplasts was found to be uniparental from the maternal plant. The growth experiment showed that Sphagnum hybrids are likely to survive in habitats with high and constant humidity, similar to the typical environment of S. quinquefarium. In such habitats they would be good competitors due to relatively high growth rate and high regeneration ability, enabling them to expand clonally and persist for long periods. The conclusion is, that interspecific gene flow in bryophytes, as exemplified by S. capillifolium and S. quinquefarium, may be more frequent and with farther reaching consequences then previously anticipated. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Associate Professor Såstad, Sigurd, Norwegian University of Science and Technology, Throndheim, Norway
organization
publishing date
type
Thesis
publication status
published
subject
keywords
taxonomi, morfologi, kemotaxonomi. Växters fysiologi (inte kärlväxter)., Sphagnum, bryophytes, morphology, phytogeography, chemotaxonomy. Physiology of nonvascular plants, Systematisk botanik, growth rate, regeneration, evolution, Systematic botany, taxonomy, introgression, maternal inheritance, recombination, hybridizarion
pages
92 pages
publisher
Apelsin Publishing
defense location
Blå Hallen Ecology building Sölvegatan 37 223 62 Lund
defense date
2006-03-31 10:00
ISBN
91-7105-237-2
language
English
LU publication?
yes
id
e475f5fc-0f16-431a-a4bc-812b69c5f456 (old id 546429)
date added to LUP
2007-09-06 10:38:30
date last changed
2016-09-19 08:45:06
@misc{e475f5fc-0f16-431a-a4bc-812b69c5f456,
  abstract     = {The aim of this thesis was to reveal details of the interspecific hybridization among bryophytes as exemplified by Sphagnum capillifolium and S. quinquefarium. I used a combination of morphometric and molecular methods, and cultivation experiments to (1) identify hybrid gametophytes, (2) reveal the contribution of each of the parents to the genomes of hybrids, (3) study the fertility of primary hybrid sporophytes, (4) explore the fitness of hybrids as compared to their parents. The results showed that S. capillifolium and S. quinquefarium are morphologically and genetically well differentiated. Hybrid sporophytes had low fertility. However, when the two species grow sympatrically, hybrid individuals are often present. They are morphologically and genetically more similar to S. capillifolium but possess a restricted number of traits and molecular markers of S. quinquefarium. A comparison with the genetic composition of hybrid gametophytes raised from primary hybrid sporophytes indicated that the natural hybrid gametophytes may be first generation recombinants. The inheritance of chloroplasts was found to be uniparental from the maternal plant. The growth experiment showed that Sphagnum hybrids are likely to survive in habitats with high and constant humidity, similar to the typical environment of S. quinquefarium. In such habitats they would be good competitors due to relatively high growth rate and high regeneration ability, enabling them to expand clonally and persist for long periods. The conclusion is, that interspecific gene flow in bryophytes, as exemplified by S. capillifolium and S. quinquefarium, may be more frequent and with farther reaching consequences then previously anticipated.},
  author       = {Natcheva, Rayna},
  isbn         = {91-7105-237-2},
  keyword      = {taxonomi,morfologi,kemotaxonomi. Växters fysiologi (inte kärlväxter).,Sphagnum,bryophytes,morphology,phytogeography,chemotaxonomy. Physiology of nonvascular plants,Systematisk botanik,growth rate,regeneration,evolution,Systematic botany,taxonomy,introgression,maternal inheritance,recombination,hybridizarion},
  language     = {eng},
  pages        = {92},
  publisher    = {ARRAY(0xb4063c8)},
  title        = {Evolutionary Processes and Hybridization within the Peat Mosses, Sphagnum},
  year         = {2006},
}