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Showing result 1 - 5 of 12 swedish dissertations matching the above criteria.

  2. 1. Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana

    Author : Reiko Akiyama; Jon Ågren; Arjen Biere; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arabidopsis thaliana; life history evolution; flowering time; germination; phenology; plant-herbivore interactions; natural selection; tolerance to leaf damage; resistance to herbivory; Plutella xylostella; Mamestra brassicae; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Abstract : In this thesis, I combined observational studies with field and greenhouse experiments to examine selection on life history traits and variation in tolerance and resistance against herbivores in natural populations of the annual herb Arabidopsis thaliana in its native range. I investigated (1) phenotypic selection on flowering time and plant size, (2) the effects of timing of germination on plant fitness, (3) the effect of leaf damage on seed production, and (4) correlations between resistance against a specialist and a generalist insect herbivore. READ MORE

  4. 2. Selection during Early Life Stages and Local Adaptation in Arabidopsis thaliana

    Author : Froukje M. Postma; Jon Ågren; Kathleen Donohue; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Dormancy cycling; Germination timing; Maternal effects; Natural variation; QTL mapping; Seed bank; Seed dormancy; Structural Equation Modeling; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Abstract : Organisms are often adapted to their local environment, but the role of early life stages in adaptive differentiation among populations remains poorly known. The aim of my thesis was to investigate the contribution of early life stages to the magnitude and genetic basis of local adaptation, and to identify the underlying adaptive traits. READ MORE

  5. 3. Population size, viability and genetic diversity in the orchid Gymnadenia conopsea

    Author : Linus Söderquist; Nina Sletvold; Sophie Karrenberg; Hans Jacquemyn; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  6. 4. Sphagnum limits : Physiology, morphology and climate

    Author : Charles Campbell; Håkan Rydin; Gustaf Granath; Sebastian Sundberg; Bengt-Gunnar Jonsson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Sphagnum; ecology; bryophyte; winter; species distribution models; low temperature; plant structure; water economy; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Abstract : Sphagnum is the most important plant genus in terms of terrestrial carbon cycling. It and the habitats it creates store an equivalent of ~68% of the CO2 in the atmosphere. The genus has little dispersal limitation and the mire habitats are functionally similar at global scales. READ MORE

  7. 5. Plant-Herbivore Interactions and Evolutionary Potential of Natural Arabidopsis lyrata Populations

    Author : Adriana Puentes; Jon Ågren; Jenny Hagenblad; Roosa Leimu Brown; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; plant defenses; leaf herbivory; floral herbivory; ontogeny; G-matrix; trade-offs; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

    Abstract : In this thesis, I combined field, greenhouse and common-garden experiments to examine the ecological and evolutionary consequences of plant-herbivore interactions and the genetic architecture of fitness-related traits in the insect-pollinated, self-incompatible, perennial herb Arabidopsis lyrata. More specifically, I examined (1) whether damage to leaves and inflorescences affects plant fitness non-additively, (2) whether trichome production is associated with a cost in terms of reduced tolerance to leaf and inflorescence damage, (3) whether young plant resistance to a specialist insect herbivore varies among populations, and (4) whether the evolution of flowering time, floral display and rosette size is constrained by lack of genetic variation or by genetic correlations among traits. READ MORE