Sökning: "Pollen tube growth rate"

Hittade 5 avhandlingar innehållade orden Pollen tube growth rate.

1. 1. Pollen Competition as a Target for Sexual Selection in Plants

   Författare :Åsa Lankinen; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sexual selection; Pollen tube growth rate; Pollen selection models; Pollen interactions; Pollen competition; Plants; Phenotypic plasticity; Non-random mating; Genotype by environment interactions; Mate choice; Viola tricolor.; Plant ecology; Växtekologi;

   Sammanfattning : According to the theory of sexual selection, traits can evolve because they confer a mating advantage in competition with members from the same sex. In animals, sexual selection is considered as an important evolutionary force. In this thesis I have investigated the potential for sexual selection in plants. LÄS MER

3. 2. 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

4. 3. Environmental effects on pollen performance:potential consequences on gene flow

   Författare :Margaret Mollel; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plant ecology; siring ability; risk assessment; pollen germination; pollen tube growth rate; Nicotiana alata; morphological markers; Cucumis sativus; Genetically modified crops hybridisation; Växtekologi;

   Sammanfattning : This thesis illustrates the effects of environmental factors on pollen performance and its importance on gene flow. Pollen competitive ability between the wild and cultivated species of four genera belonging to Cucurbitaceae family was compared to evaluate the evolutionary potential for selection on pollen tube growth rate. LÄS MER

5. 4. Effects of Environmental Factors on maternal Choice and Gene Dispersal in Plants

   Författare :Teklehaimanot Haileselassie; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; siring ability; Maternal effect; genetically modified crops; risk assessment; morphological markers; herbivory; Cucumis sativus; Växtekologi; pollen tube growth rate; Plant ecology; Nicotiana alata;

   Sammanfattning : Gene dispersal through pollen is affected by both abiotic and biotic environmental factors. In this study, I mainly investigated the effect of environmental factors: nutrient availability, simulated herbivory and floral morphology (flower colour), on the siring success of competing pollen donors and fitness of the resulting offspring. LÄS MER

7. 5. 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