Search for dissertations about: "polyploidy"

Showing result 1 - 5 of 22 swedish dissertations containing the word polyploidy.

  2. 1. Evolution of asexuality in insects : Polyploidy, hybridization and geographical parthenogenesis

    Author : Magnus Lundmark; Anssi Saura; Anders Nilsson; Davis Parker; Umeå universitet; []
    Keywords : Molecular genetics; weevils; geographical parthenogenesis; hybridization; polyploidy; Genetik; Otiorhynchus; Genetics; genetik;

    Abstract : Asexual reproduction and polyploidy are relatively rare in animals with chromosomal sex determination and always represent a derived condition. To accomplish asexual reproduction several changes in gene expression are required in the mechanism of oogenesis. READ MORE

  4. 2. Plant polyploidy and interactions with insect herbivores

    Author : Leena Arvanitis; Johan Ehrlén; Christer Wiklund; John N. Thompson; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; diversicifation; herbivory; host plant preference; plant galls; plant-insect interactions; plant polyploidy; selection; spatial variation; trait-fitness relationship; Terrestrial ecology; Terrestisk ekologi; Plant Ecology; växtekologi;

    Abstract : Polyploidization has been suggested to be a common mechanism for plant speciation. Polyploidy is associated with changes in plant traits and altered habitat preference. READ MORE

  5. 3. Systematics and polyploid evolution in Potentilleae (Rosaceae)

    Author : Magnus Lundberg; Torsten Eriksson; Jürg Schönenberger; Bengt Oxelman; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Potentilleae; Fragariinae; Potentilla; Sibbaldia; Fragaria; Alchemilla; systematics; phylogeny; polyploidy; autopolyploidy; allopolyploidy; reticulate evolution; Systematics and phylogenetics; Systematik och fylogeni; växtsystematik; Plant Systematics;

    Abstract : This thesis comprises studies of the phylogenetic relationships in the flowering plant clade Potentilleae in Rosaceae. The relationships were elucidated by using DNA sequence data from the nuclear genome as well as from the plastid genome. In particular, the focus of the studies was the investigation of allopolyploidy, i.e. READ MORE

  6. 4. Reticulate Evolution in Diphasiastrum (Lycopodiaceae)

    Author : Sunniva Margrethe Due Aagaard; Niklas Wikström; Tom A. Ranker; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; admixture analysis; Bayesian clustering; Diphasiastrum; Feulgen DNA image densitometry; homoploid hybridization; Lycopodiaceae; phylogenetic analysis; polyploidy; reticulate evolution; Systematics and phylogenetics; Systematik och fylogeni; systematisk botanik; Systematic Botany;

    Abstract : In this thesis relationships and the occurrence of reticulate evolutionary events in the club moss genus Diphasiastrum are investigated. Diphasiastrum is initially established as a monophyletic group within Lycopodiaceae using non recombinant chloroplast sequence data. READ MORE

  7. 5. Genomic and phenotypic consequences of allopolyploidization in Capsella

    Author : Tianlin Duan; Martin Lascoux; Adrien Sicard; Sylvain Glémin; Barbara Mable; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Allopolyploidy; Polyploidy; Hybridization; Neopolyploid lines; Gene expression; Self-incompatibility; Capsella bursa-pastoris;

    Abstract : Allopolyploidization, the combination of whole-genome duplication (WGD) and interspecific hybridization, is a frequent and influential event in plant evolution. Allopolyploidization potentially affects both adaptation and diversification, yet the understanding of the consequences of allopolyploidy has been obscured by several issues. READ MORE