Search for dissertations about: "floral"

Showing result 1 - 5 of 54 swedish dissertations containing the word floral.

  2. 1. Evolutionary Ecology of Floral Traits in Fragrant Orchids

    Author : Elodie Chapurlat; Nina Sletvold; Jon Ågren; Magne Friberg; Kathleen Kay; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; agents of selection; diurnal and nocturnal pollination; divergent selection; field experiment; floral evolution; floral scent; Gymnadenia conopsea; Gymnadenia densiflora; Orchidaceae; phenotypic selection; pollinator-mediated selection; spatial variation; scent rhythm;

    Abstract : Why are flowers so diverse? Much of floral evolution is thought to be driven by pollinator-mediated selection. However, the connection between macroevolutionary patterns of floral diversity and microevolutionary processes remains poorly understood. In this thesis, I have used the fragrant orchids Gymnadenia conopsea s.s. READ MORE

  4. 2. The evolutionary ecology of plant reproductive diversity and floral signals : Mating system and floral scent in Arabis alpina

    Author : Hampus Petrén; Biodiversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arabis alpina; floral scent; intraspecific variation; mating system; parental conflict; phenotypic plasticity; phenotypic selection; reproductive isolation; speciation; volatile organic compound VOC ;

    Abstract : Flowering plants display an extraordinary floral- and reproductive diversity. Variation in the size, shape, colour and scent of flowers, and in systems and strategies of mating, is ubiquitous in comparisons of different species, but also exists among different conspecific populations. READ MORE

  5. 3. Selection and Floral Evolution in Platanthera bifolia and P. chlorantha (Orchidaceae)

    Author : Johanne Maad; Charles B. Fenster; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Evolution; phenotypic selection; male function hypothesis; mating systems; floral shifts; orchids; pollination; moth pollinators; Platanthera.; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; systematisk botanik; Systematic Botany;

    Abstract : Natural selection mediated by pollinators has influenced the evolution of floral diversity of the flowering plants (angiosperms). The scope of this thesis was to study: 1) phenotypic selection, 2) mating systems, and 3) floral shifts involved in plant speciation. Model plant species were Platanthera bifolia and P. chlorantha (Orchidaceae). READ MORE

  6. 4. Pollinator-mediated selection and the evolution of floral traits in orchids

    Author : Judith Trunschke; Jon Ågren; Nina Sletvold; Allan G. Ellis; Uppsala universitet; []
    Keywords : Among-population variation; Ecotype; Field experiment; Floral evolution; Germination; Local adaptation; Orchidaceae; Platanthera bifolia; Phenotypic selection; Pollination; Reciprocal transplant; Trait manipulation; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Abstract : In this thesis, I combined manipulations of traits and pollination environment with analysis of phenotypic selection to examine causes of variation in strength and mode of selection on floral traits, and I conducted a reciprocal sowing experiment to test for local adaptation in germination success. I tested the following predictions (1) the opportunity for selection, and the strength of pollinator-mediated and net selection increase with increasing pollen limitation, (2) the effects of traits affecting pollinator attraction and traits affecting pollination efficiency are non-additive and this leads to pollinator-mediated correlational selection, (3) the effects of spur length on pollen removal, pollen receipt, and female fitness differ between populations with short-tongued and populations with long-tongued pollinators, and (4) local adaptation at the stage of germination contributes to the maintenance of ecotypes growing in grasslands and woodlands, respectively. READ MORE

  7. 5. Plant-Animal Interactions and Evolution of Floral Display and Flowering Phenology in Arabidopsis lyrata

    Author : Saskia Sandring; Jon Ågren; Johan Ehrlén; José Gómez; Uppsala universitet; []
    Keywords : Ecology; Arabidopsis lyrata; natural selection; floral display; phenology; flowering time; plant-animal interactions; pollination; herbivory; selection gradients; population differentiation; local adaptation; Ekologi;

    Abstract : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits, and population differentiation in the insect-pollinated, outcrossing, perennial herb Arabidopsis lyrata. More specifically, I (1) determined whether selection on flowering phenology and floral display can be attributed to interactions with pollinators and herbivores, (2) examined whether population differentiation in flowering phenology and floral display is correlated with current selection on these traits, and (3) tested for local adaptation from contrasting environments in Europe. READ MORE