Sökning: "outcrossing"

Visar resultat 1 - 5 av 12 avhandlingar innehållade ordet outcrossing.

  1. 1. The ecological significance of cleistogamy

    Författare :Henrik Berg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; bet-hedging; chasmogamous; enviromnental variation; fitness; outcrossing; progeny; selling; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Various aspects of cleistogamy, a reproductive system combining selfing in closed (cleistogamous) flowers and potential outcrossing in open (chasmogamous) flowers, were investigated in four perennial species. The main purpose was to shed some light on the adaptive value of having a dual reproductive strategy, and to test some hypotheses on the maintenance of xenogamy. LÄS MER

  3. 2. 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

  4. 3. Opportunities in small population breeding in black cottonwood : or The little population that could

    Författare :Rami-Petteri Apuli; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Small and structured populations are problematic for breeding due to low levels of genetic variability and increased levels of linkage disequilibrium (LD). The increased LD causes problems with utilization of common genomic tools and may lead into increased accruement of deleterious alleles through the intense selection and bottlenecks characteristic of breeding. LÄS MER

  5. 4. Genetic, morphological and chemical variation in the genus Harpagophytum

    Författare :Mbaki Muzila; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Harpagophytum procumbens is a valuable medicinal plant but mistakes with plant identification at harvesting, and wilful adulteration using the presumably less efficient H. zeyheri are suggested. A multidisciplinary study with plant material from Botswana was conducted. LÄS MER

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

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

    Sammanfattning : 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. LÄS MER