Sökning: "species pairs"

Visar resultat 1 - 5 av 73 avhandlingar innehållade orden species pairs.

  1. 1. Phylogenetic Studies in Usnea (Parmeliaceae) and Allied Genera

    Författare :Kristina Articus; Leif Tibell; Mats Wedin; Jan-Eric Mattsson; Philippe Clerc; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Usnea; Neuropogon; Dolichousnea; Eumitria; Protousnea; Parmeliaceae; phylogeny; taxonomy; species pairs; morphology; ITS-LSU; β-tubulin; mtSSU; Biologi; Biology; Biologi;

    Sammanfattning : This thesis deals with the phylogeny of the lichen genus Usnea (Parmeliaceae, Ascomycetes). The relationships and the morphological variation among Usnea species has been studied, as well as the relationship of Usnea to allied genera. Two species, U. florida and U. LÄS MER

  3. 2. The use of molecular markers for identifying species diversity and functional variation of ectomycorrhizal fungi

    Författare :Jenny Hedh; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ectomycorrhiza; molecular markers; Paxillus involutus; ITS region; phylogenetic species; host compatibility; gene expression; CGH;

    Sammanfattning : Ectomycorrhiza (EM) is a symbiosis between soil living fungi and the roots of woody plants. EM fungal communities are important in forest nutrient cycling, they are species rich and their structures vary between habitats and over time. LÄS MER

  4. 3. Reconciling gene family evolution and species evolution

    Författare :Joel Sjöstrand; Jens Lagergren; Nicolas Lartillot; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computational biology; Bioinformatics; Phylogenetics; Phylogenomics; Comparative genomics; Evolutionary biology; datalogi; Computer Science;

    Sammanfattning : Species evolution can often be adequately described with a phylogenetic tree. Interestingly, this is the case also for the evolution of homologous genes; a gene in an ancestral species may – through gene duplication, gene loss, lateral gene transfer (LGT), and speciation events – give rise to a gene family distributed across contemporaneous species. LÄS MER

  5. 4. Genetics and the Origin of Two Flycatcher Species

    Författare :Thomas Borge; Glenn-Peter Saetre; Staffan Bensch; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; reinforcement; reproductive isolation; Z chromosome; hybridization; mate-choice; single nucleotide polymorphism; sequence variation; sexual selection; recombination; Biologi; Biology; Biologi;

    Sammanfattning : In this thesis, different genetic tools are used to investigate pre- and postzygotic barriers to gene exchange and their role in speciation in the pied flycatcher (Ficedula hypoleuca) and the collared flycatcher (F. albicollis). This species complex consists of four genetically distinct clades that apparently diverged in allopatry (I). LÄS MER

  7. 5. Phylogeny and species delimitation in Roccellaceae and Physciaceae (Euascomycetes)

    Författare :Katileena Lohtander; Mats Wedin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systematics and phylogenetics; Systematik och fylogeni; systematisk botanik; Systematic Botany;

    Sammanfattning : DNA sequence data (the ITS region and Group I Introns) from the nuclear ribosomal repeat (rDNA), partial β-tubulin gene sequences, RAPD markers, and some morphological characters were analysed phylogenetically in order to examine relationships in lichenized Euascomycetes, from the species level to higher taxonomic levels. The species level studies comprise some so-called species pairs in two families, Roccellaceae (Arthoniales) and Physciaceae (Lecanorales). LÄS MER