Vis enkel innførsel

dc.contributor.authorKornstad, Torbjørn Horsberg
dc.date.accessioned2014-09-26T10:51:31Z
dc.date.available2014-09-26T10:51:31Z
dc.date.copyright2014
dc.date.issued2014-09-26
dc.identifier.urihttp://hdl.handle.net/11250/221780
dc.description.abstractSpecies that possess more than two sets of chromosomes are denoted as polyploids. It is hypothesized that polyploids show high gene redundancy, hybrid vigour and masking of deleterious alleles, and that this make them better at adapting to novel environments because of wider phenotypic response range. It is also speculated that adaptive advantage of polyploidy contributes to invasiveness as there is a trend that polyploids are overrepresented within invasive species. The allopolyploid Arabidopsis suecica and its parent species A. arenosa and A. thaliana were chosen as a model system to investigate relationships between phenotypic plasticity, fitness and genetic variation. In this thesis I try to uncover genetic structures in the study species, and I investigate if A. suecica show higher plasticity and/or fitness than its parent species, if the different species show different levels of genetic diversity and whether A. suecica could work as a model for studying polyploidy and invasiveness. Three to four wild Norwegian populations of each species were analyzed for phenotypic responses to differences in availability of nutrient and light, while population structure and genetic diversity was assessed through analysis of AFLP markers. The species were separated into genetic and phenotypic clusters with A. suecica being intermediate between its parent species. Clear population structure was inferred in A. thaliana and A. arenosa, while no structure was inferred in A. suecica. The species exhibited similar phenotypic responses. A. arenosa seemed to have higher phenotypic plasticity and higher genetic diversity than the two other species, probably related to its outbreeding reproduction strategy. Furthermore, a general positive relationship between genetic diversity and phenotypic plasticity was found. Low genetic diversity and more population structure were found in the indigenous, inbreeding A. thaliana. Population spacing might explain the clear genetic structure in A. arenosa, while the lack of structure in A. suecica could be due to coherent populations. When it came to fitness measured as allocation of resources to reproduction, the trend pointed towards A. arenosa having lower fitness under poor environmental conditions. A. suecica, on the other hand, showed the ability to keep up fitness under different environmental conditions, which makes it a promising model for investigating invasiveness and polyploidy. Still, further studies are needed to confirm this.nb_NO
dc.language.isoengnb_NO
dc.publisherNorwegian University of Life Sciences, Ås
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Økologi: 488nb_NO
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Basale biofag: 470::Genetikk og genomikk: 474nb_NO
dc.subjectPolyploidynb_NO
dc.subjectInvasive speciesnb_NO
dc.subjectPhenotypic plasticitynb_NO
dc.subjectFitnessnb_NO
dc.subjectGenetic variationnb_NO
dc.titlePhenotypic and genotypic variation in the allopolyploid Arabidopsis suecica and its parent species A. thaliana and A. arenosa : an investigation of a possible model for studies of polyploidy and invasivenessnb_NO
dc.title.alternativeFenotypiske og genotypiske variasjonar i den allopolyploide arten Arabidopsis suecica og foreldreartane A. thaliana og A. arenosa: Ei undersøking av ein mogleg modell for studium av polyploidi og invasibilitetnb_NO
dc.typeMaster thesisnb_NO
dc.source.pagenumber53nb_NO
dc.description.localcodeM-ECOLnb_NO


Tilhørende fil(er)

Thumbnail

Denne innførselen finnes i følgende samling(er)

Vis enkel innførsel