Avancerad sökning

Hittade 3 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Plant-animal interactions and seed output of two insectpollinated herbs

    Författare :Anna R. Waites; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; plant reproduction; pollen limitation; pollinator behaviour; heterostyly; seed predation; Lythrum salicaria; Pedicularis palustris; stigma receptivity; self-pollen; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : I combined comparative and experimental studies in the field and in the greenhouse to examine factors influencing reproductive success in two insect-pollinated herbs, the tristylous, selfincompatible perennial Lythrum salicaria and the self-compatible, biennial Pedicularis palustris. More specifically, I explored (i) the effects of plant population characteristics on the intensity and outcome of interactions with pollinators and seed predators, (ii) whether flower morphology affects duration of stigma receptivity, and (iii) whether damage-induced reduction in floral display reduces pollinator visitation and increases pollen limitation. LÄS MER

  2. 2. Population size, viability and genetic diversity in the orchid Gymnadenia conopsea

    Författare :Linus Söderquist; Nina Sletvold; Sophie Karrenberg; Hans Jacquemyn; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; demography; extinction probability; genetic diversity; genetic rescue; genetic structure; Gymnadenia conopsea; orchid conservation; population viability; population size; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : In this thesis, I combined controlled crosses with genetic and demographic data to examine how a main conservation value indicator, population size, was associated with estimates of population viability. I focused on the still common, but decreasing, perennial orchid Gymnadenia conopsea at two spatial scales—locally on the island Öland, in SE Sweden, and regionally across Scandinavia. LÄS MER

  3. 3. Evolutionary consequences of dominance at the Brassicaceae self-incompatibility locus

    Författare :Jörg Alexander Bachmann; Tanja Slotte; Vincent Castric; Ove Eriksson; Pär Ingvarsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Capsella; mating system shift; self-fertilization; self-incompatibility; small RNA; dominance; Arabidopsis; population genetics; genomics; gene expression; ekologi och evolution; Ecology and Evolution;

    Sammanfattning : Self-incompatibility (SI) is a genetic mechanism that allows plants to enforce outcrossing by rejecting self-pollen and pollen from close relatives. In the Brassicaceae, SI is sporophytic and controlled by the self-incompatibility locus (S-locus). LÄS MER