Sökning: "Seed Selection"

Visar resultat 1 - 5 av 51 avhandlingar innehållade orden Seed Selection.

  1. 1. Male and female selective mechanisms, reproductive success and gene flow

    Författare :Samuel Kiboi; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; Cucumis sativus.; genetic marker; gene flow; reproduction; embryo abortion; resistance; maternal selection; sexual selection; pollen competition; selection;

    Sammanfattning : In this thesis, I have studied male and female selective mechanisms that can affect plant reproductive success and gene flow. I have focussed on sexually selected traits, mainly pollen competition and maternal sorting mechanisms, for example through non-random ovule abortion. LÄS MER

  3. 2. Plant-seed predator interactions – ecological and evolutionary aspects

    Författare :Hannah Östergård; Johan Ehrlén; Peter Hambäck; William Kunin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; apparent competition; community context; fruit abortion; defence; host range; monophagous; offence; oligophagous; plant-animal interactions; pre-dispersal seed predation; selection; spatio-temporal variation; Biology; Biologi; Plant Ecology; växtekologi;

    Sammanfattning : Plant-animal interactions are affected by both abundance and distribution of interacting species and the community context in which they occur. However, the relative importance of these factors is poorly known. LÄS MER

  4. 3. Long-term studies of succession : Colonisation and seed banks

    Författare :Ulf Grandin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Ellenberg indicator values; genetic variation; long-term study; Lythrum salicaria; Moehringia trinervia; primary succession; seed bank; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Using data from long-term studies of the vegetation in two areas under primary succession, patterns of colonisation and the accumulated seed bank during plant succession were studied.At century-old small islands in Lake Hjälmaren, Sweden, the genetic structure of differently old populations of Moehringia trinervia and Lythrum salicaria was studied, using allozyme variation for M. LÄS MER

  5. 4. Selection on floral traits in Primula farinosa

    Författare :Didrik Vanhoenacker; Johan Ehrlén; Jon Ågren; Arjen Biere; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coevolution; correlational selection; Falseuncaria ruficiliana; geographic mosaic; hand pollination; Hermann Müller; interaction strength; plant-insect interactions; pollen limitation; selection strength; spatiotempora; Uta stansburiana; Biology; Biologi; Plant Ecology; växtekologi;

    Sammanfattning : Flowers and inflorescences have evolved in relation to animals for at least 100 million years. Plants attract pollinators with large, conspicuous, bright-coloured or scented flowers. These display attributes, however, also attract herbivores. LÄS MER

  7. 5. Evolutionary consequences of sex-specific selection

    Författare :Josefine Stångberg; Elisabeth Bolund; Elina Immonen; Jennifer Perry; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Caenorhabditis remanei; Callosobruchus maculatus; sex-specific selection; sexual selection; experimental evolution; intralocus sexual conflict; life history evolution; sexual dimorphism; trade-offs; Quantitative genetics;

    Sammanfattning : Sex-specific selection is widespread, evident by the evolution of sexual dimorphism in many traits in sexually reproducing taxa. The reason why the sexes may experience selection that differs in direction or magnitude is often linked to the reproductive strategies associated with the sex-specific reproductive physiology. LÄS MER