Sökning: "botany"
Visar resultat 21 - 25 av 404 avhandlingar innehållade ordet botany.
21. The significance of ethylene and ETHYLENE RESPONSE FACTORS in wood formation of hybrid aspen
Sammanfattning : The woody tissues serve to stabilise plants, store nutrients and translocate water and minerals. The formation of wood, or ’secondary xylem’, follows a well-defined developmental gradient which is initiated by cell division activity in the vascular cambium. LÄS MER
22. Evolution of Lycopodiaceae (Lycopsida) : Relationships and Patterns of Diversification
Sammanfattning : A series of phylogenetic analyses using nucleotide sequence data resolves many aspects of the relationships in a group of land plants that until now have received comparatively little attention, the homosporous lycopsids or Lycopodiaceae. Although the group has evolved as an isolated lineage ever since the Late Devonian (more than 470 Myr ago), little is known about how modern species diversity relate to this ancient history. LÄS MER
23. Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana
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
24. Mechanisms of plant root xylem developmental plasticity in response to water deficiency and salt
Sammanfattning : Plants may be exposed to a variety of different environmental conditions including water deficiency and salt, both affecting the uptake of water into the plant. Water is taken up from the soil by the roots and distributed throughout the plant via the water conducting tissue, the xylem. LÄS MER
25. Sphagnum limits : Physiology, morphology and climate
Sammanfattning : Sphagnum is the most important plant genus in terms of terrestrial carbon cycling. It and the habitats it creates store an equivalent of ~68% of the CO2 in the atmosphere. The genus has little dispersal limitation and the mire habitats are functionally similar at global scales. LÄS MER
