Sökning: "delayed fertilization"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden delayed fertilization.

  1. 1. Reproductive Biology and Population Genetics of Common Ash (Fraxinus excelsior L.)

    Författare :Grazyna Bochenek; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :Fraxinus excelsior; delayed fertilization; functional dioecy; gender-related grow difference; inbreeding; tree-rings; non random mating; wind-pollination;

    Sammanfattning : Common Ash, Fraxinus excelsior L. (Oleaceae) is a wind-pollinated, wind-dispersed, deciduous tree, commonly occurring throughout Central and Northern Europe. The thesis addresses several questions concerning reproductive biology and factors influencing the genetic richness of ash stands. LÄS MER

  2. 2. Sexual conflict and selection on pistil and pollen traits

    Författare :Josefin Madjidian; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Antagonistic trait; Collinsia heterophylla; delayed stigma receptivity; direct cost; first-donor advantage; gender bias; heritability; indirect benefit; mate choice; mixed-mating system; paternal diversity; pollen competition; pollen deposition; pollen load size; pollen tube growth rate; self-compatibility; semantics; sexual conflict; sexual selection; sexually antagonistic co-evolution;

    Sammanfattning : The incidence of sexual selection in plants is today acknowledged, however, just as in animals, evolution and maintenance of mate choice is gravely underexplored. Moreover, the potential for sexual conflicts to occur in plants has only been assessed empirically to a very limited degree. LÄS MER

  3. 3. Nutrient supply to reed canary grass as a bioenergy crop : intercropping and fertilization with ash or sewage sludge

    Författare :Eva Lindvall; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []

    Sammanfattning : Production of renewable energy from herbaceous crops on agricultural land is of great interest since fossil fuels need to be replaced with sustainable energy sources. Reed canary grass (RCG), Phalaris arundinacea L. is an interesting species for this purpose. LÄS MER

  4. 4. Ecological genetics of inbreeding, outbreeding and immunocompetence in Ranid frogs

    Författare :Jörgen Sagvik; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :;

    Sammanfattning : Using artificial fertilization, I crossed frogs from different populations to evaluate fitness consequences for the offspring from an inbreeding-outbreeding perspective, and to evaluate quantitative genetic effects on immunocompetence against a fungal pathogen (Saprolegnia). Crosses between closely situated populations of different sizes generated contrasting results for the effects of outbreeding on offspring traits between populations and life history stages, emphasizing the importance of epistatic effects and the difficulties of relying on generalizations when making conservation decisions (e. LÄS MER

  5. 5. Regulatory Control of Autumn Senescence in Populus tremula

    Författare :Edlund Erik; Stefan Jansson; Paul Dijkwel; Umeå universitet; []
    Nyckelord :AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Aspens; Girdling; Anthocyanins; Arginine; Autumn Senescence; Cytokinins; Populus tremula; Asp; Ringbarkning; Antocyanin; Arginin; Höstlöv; Cytokinin; Populus tremula; Physiological Botany; fysiologisk botanik;

    Sammanfattning : Autumn senescence is a visually spectacular phenomenon in which trees prepare for the oncoming winter. The mechanism for regulation of autumn senescence in trees has been very hard to pinpoint. In this thesis the main focus is to investigate how autumn senescence is regulated in aspens (Populus tremula). LÄS MER