Sökning: "inbreeding"

Visar resultat 21 - 25 av 71 avhandlingar innehållade ordet inbreeding.

1. 21. Genetic variation and population differentiation in the forest herb Lathyrus vernus (Fabaceae)

   Författare :Katarina Schiemann; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .; taxonomy; morphology; phytogeography; inbreeding depression; Systematic botany; small population size; marginality; reproductive characters; leaflet shape; allozymes; Lathyrus vernus; genetic variation;

   Sammanfattning : In the present thesis, I investigated patterns of genetic variation in the forest herb Lathyrus vernus (Fabaceae), using plant material from different-sized populations representing three geographically separated regions: central Europe, southern and central Sweden. My studies included presumably neutral or weakly selected characters (allozymes and leaflet shape) as well as characters that should be under strong directional selection (e. LÄS MER

3. 22. Ecological genetics of inbreeding, outbreeding and immunocompetence in Ranid frogs

   Författare :Jörgen Sagvik; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Using artificial fertilization, I crossed frogs from different populations to evaluate fitness consequences for the offspring from an inbreeding-outbreeding perspective, and to evaluate quantitative genetic effects on immunocompetence against a fungal pathogen (Saprolegnia). Crosses between closely situated populations of different sizes generated contrasting results for the effects of outbreeding on offspring traits between populations and life history stages, emphasizing the importance of epistatic effects and the difficulties of relying on generalizations when making conservation decisions (e. LÄS MER

4. 23. Genetic variation, polyploidy and hybridization in Scandinavian Anthericum ramosum and A. liliago (Anthericaceae)

   Författare :Gabrielle Rosquist; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systematic botany; inbreeding depression; gene flow; introgression; hybridization; morphology; isozyme; allozyme; allele frequencies; population fragmentation; genetic diversity; geographic variation; Anthericum; Allopolyploidy; taxonomy; phytogeography; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .;

   Sammanfattning : In this thesis, I investigate the differences in breeding system, levels of genetic variation and hierarchical structure of genetic diversity between Anthericum ramosum and A. liliago. The two species differ in ploidy level and flowering time, but have similar habitat preferences, reproductive biology and geographic distributions in Scandinavia. LÄS MER

5. 24. Patterns of geographic variation in Silene section Elisanthe (Caryophyllaceae): hybridization and migrational history

   Författare :Louise Hathaway; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chemotaxonomy. Physiology of nonvascular plants; phytogeography; morphology; outbreeding depression; Systematic botany; taxonomy; ITS; fitnes; inbreeding depression; AFLP; PCR-RFLP; cpDNA; gene flow; postglacial migration; geographic variation; hybridization; Silene latifolia; Silene section Elisanthe; Silene dioica; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .;

   Sammanfattning : Large-scale patterns of genetic variation in chloroplast (cp) and nuclear DNA in the widespread European herb species Silene latifolia and S. dioica were investigated using cpPCR-RFLPs, non-coding cpDNA sequences, AFLPs and sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA). LÄS MER

7. 25. Effects of inbreeding and selection on bristle number in Drosophila melanogaster

   Författare :Marianne Rasmuson; Stockholms högskola; []
   Nyckelord :;

   Sammanfattning : .... LÄS MER