Sökning: "germination time"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden germination time.

1. 1. Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana

   Författare :Reiko Akiyama; Jon Ågren; Arjen Biere; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arabidopsis thaliana; life history evolution; flowering time; germination; phenology; plant-herbivore interactions; natural selection; tolerance to leaf damage; resistance to herbivory; Plutella xylostella; Mamestra brassicae; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

   Sammanfattning : In this thesis, I combined observational studies with field and greenhouse experiments to examine selection on life history traits and variation in tolerance and resistance against herbivores in natural populations of the annual herb Arabidopsis thaliana in its native range. I investigated (1) phenotypic selection on flowering time and plant size, (2) the effects of timing of germination on plant fitness, (3) the effect of leaf damage on seed production, and (4) correlations between resistance against a specialist and a generalist insect herbivore. LÄS MER

3. 2. Seed dormancy and germination in an ecological context : comparative studies of annual weeds

   Författare :Laila Karlsson; Per Milberg; Ken Thompson; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asteraceae; Bidens; Compositae; deadnettle; Galinsoga; germination timing; Guizotia; evolution; Labiatae; Lamiaceae; Lamium; morphophysiological dormancy; Papaveraceae; Papaver; Parthenium; physiological dormancy; poppy; summer annual; Tagetes; Verbesina; winter annual; Biology; Biologi;

   Sammanfattning : Germination ecology studies, i.e. studies of interactions between characteristics of the seeds and environmental circumstances, provide understanding of spatial and temporal patterns of emergence of wild species, as weeds in the field. A large number of species have seed dormancy, i. LÄS MER

4. 3. Wooded or treeless pastures? : Linking policy, farmers' decisions and biodiversity

   Författare :Simon Jakobsson; Regina Lindborg; Sara A O Cousins; Jan Plue; Tim Benton; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bat; biodiversity; bird; canopy cover; Common Agricultural Policy; European Union; farmer; functional diversity; germination; grassland; multi-taxa; pasture; plant; policy; seed sowing; tree density; trees; Physical Geography; naturgeografi;

   Sammanfattning : Worldwide, biodiversity conservation is one of the key challenges for a sustainable future of nature and society. It is particularly important to preserve high quality habitats within otherwise intensively managed agricultural landscapes. LÄS MER

5. 4. Ecology and evolution of local adaptation in Arabidopsis thaliana

   Författare :Giulia Zacchello; Jon Ågren; Xavier Picó; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arabidopsis thaliana; germination time; natural populations; Near isogenic lines; reciprocal transplants; seed bank; seed dormancy; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

   Sammanfattning : In this thesis, I investigate the ecological genetics of local adaptation in the annual herb Arabidopsis thaliana with the aim to identify key traits, agents of selection, and genomic regions contributing to adaptive differentiation. The thesis focuses on adaptive differentiation in timing of germination and seed dormancy between populations located close to the southern and northern range margins in Europe. LÄS MER

7. 5. Adaptation and Constraint in the Plant Reproductive Phase

   Författare :Kjell Bolmgren; Ove Eriksson; Bengt Oxelman; Jeff Ollerton; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phenology; fleshy fruits; phylogenetic comparative methods; phylogenetic constraints; Rhamnus; Frangula; Frangula alnus; key innovations; allometry; diversity; phylogeny; seed size; frugivory; germination; recruitment; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : Conservatism is a central theme of organismic evolution. Related species share characteristics due to their common ancestry. Some concern have been raised among evolutionary biologists, whether such conservatism is an expression of natural selection or of a constrained ability to adapt. LÄS MER