Sökning: "genetic variation"

Visar resultat 16 - 20 av 823 avhandlingar innehållade orden genetic variation.

  1. 16. Population size, viability and genetic diversity in the orchid Gymnadenia conopsea

    Författare :Linus Söderquist; Nina Sletvold; Sophie Karrenberg; Hans Jacquemyn; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; demography; extinction probability; genetic diversity; genetic rescue; genetic structure; Gymnadenia conopsea; orchid conservation; population viability; population size; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : In this thesis, I combined controlled crosses with genetic and demographic data to examine how a main conservation value indicator, population size, was associated with estimates of population viability. I focused on the still common, but decreasing, perennial orchid Gymnadenia conopsea at two spatial scales—locally on the island Öland, in SE Sweden, and regionally across Scandinavia. LÄS MER

  3. 17. Quantitative genetic variation in declining plant populations

    Författare :Maarten Ellmer; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Saxifraga granulata; Briza media; Nigella degenii; bottleneck; Inbreeding depression; founder effects; drift; quantitative genetic; diversifying selection; habitat fragmentation; small populations;

    Sammanfattning : The ecological and genetic effects of habitat fragmentation are an issue of major concern in current conservation biology. Habitat fragmentation results in smaller habitat areas and as a consequence smaller and more isolated populations. Many habitats have become fragmented through human activities such as forestry and agricultural development. LÄS MER

  4. 18. Linkage maps in studies of genetic variation - examples from Beta vulgaris

    Författare :Thomas Kraft; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cytogenetics; Genetics; Beta vulgaris; Linkage maps; genetic variation; Genetik; cytogenetik;

    Sammanfattning : Today, most studies of genetic variation utilise molecular markers, making it possible to detect variation at the DNA level. This has greatly facilitated studies of genetic variation in population and evolutionary genetics, systematics and transmission genetics. LÄS MER

  5. 19. On the aetiology of ALS : a comprehensive genetic study

    Författare :Caroline Ingre; Peter M Andersen; Rayomand Press; Siddharthan Chandran; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; ALS; risk factor; VAPB; SOD1; amyotrophic lateral sclerosis; ATXN2; SMN1; SMN2; PFN1; 50 bp deletion in SOD1 promotor; population-specific genetic variations; Neurology; neurologi;

    Sammanfattning : Introduction: Amyotrophic lateral sclerosis (ALS) is a deadly, progressive neuromuscular disease that affects individuals all over the world. About 10% of the patients have a familial predisposition (FALS) while the remainder of cases are isolated or sporadic (SALS) and of unknown cause. LÄS MER

  7. 20. Geographic Distribution of Intra-specific Variation in Widespread Eurasian boreo-nemoral Woodland Herbs

    Författare :Torbjörn Tyler; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kemotaxonomi. Växters fysiologi inte kärlväxter .; Plant genetics; Växtgenetik; morfologi; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; taxonomi; phytogeography; morphology; taxonomy; historical biogeography; Systematic botany; allozymes; population differentiation; postglacial migration; genetic variation; geographic variation;

    Sammanfattning : Many woodland plant species have huge distribution areas covering large parts of the Eurasian continent including areas that were glaciated during the last glacial period. In the present thesis, the geographic distribution of variation within such species is investigated and discussed in relation to glacial survival and post-glacial migration, dispersal ability, breeding system and levels of gene-flow between populations and related species, and various methods to measure and analyse genetic variation. LÄS MER