Avancerad sökning

Hittade 3 avhandlingar som matchar ovanstående sökkriterier.

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

    Författare :Josefin Madjidian; Biologiska institutionen; []
    Nyckelord :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. 2. Breeding System Evolution and Pollination Success in the Wind-Pollinated Herb Plantago maritima

    Författare :Emil Nilsson; Jon Ågren; Pia Mutikainen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Breeding system; mating system; gynodioecy; male sterility; reproductive output; self-compatibility; self-incompatibility; wind-pollination; founder event; genetic structure; Biologi; Biology; Biologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : In this thesis, I examined variation in sex expression and mating patterns in the sexually polymorphic, wind-pollinated herb Plantago maritima. With a combination of field studies, greenhouse experiments, and genetic analyses, I (a) examined factors influencing sex ratio variation in gynodioecious plants (in which hermaphrodites and females coexist), (b) discovered variation in breeding system, (c) investigated density-dependence of seed production, and (d) documented genetic variation within and among populations close to the northern range margin in Europe. LÄS MER

  4. 3. On the Evolution of Reproductive Systems in Neurospora

    Författare :Rebecka Strandberg; Hanna Johannesson; Paul Dyer; Uppsala universitet; []
    Nyckelord :Neurospora; mating type; pheromone receptor; phylogeny; gene expression; heterothallism; homothallism; pseudohomothallism; alternative splicing; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

    Sammanfattning : The aim of this thesis was to study the evolution of reproductive systems and reproductive traits in the fungal genus Neurospora. More specifically, I have investigated the evolutionary forces shaping the genes involved in sexual reproduction, focusing on mating-type (mat) and pheromone receptor (pre) genes. LÄS MER