Search for dissertations about: "fruit evolution"

Showing result 1 - 5 of 25 swedish dissertations containing the words fruit evolution.

  2. 1. Evolution and biodiversity of the Ixoroideae (Rubiaceae)

    Author : Kent Kainulainen; Birgitta Bremer; Sylvain Razafimandimbison; Torsten Eriksson; Sandra Knapp; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Alberteae; character evolution; classification; Condamineeae; fruit evolution; Ixoroideae; phylogenetics; pollen presentation; Rubiaceae; systematics; taxonomy; Systematics and phylogenetics; Systematik och fylogeni; växtsystematik; Plant Systematics;

    Abstract : The phylogenetic relationships within subfamily Ixoroideae of the coffee family are investigated by phylogenetic reconstruction of molecular data, including regions of the chloroplast DNA (matK, ndhF, rbcL, rps16, trnH-psbA, trnS-G, and trnT-F), and the nuclear ribosomal DNA (ITS). The evolution of morphological characters within the group are inferred, with focus on characters used in classification. READ MORE

  4. 2. Pollinator-mediated selection and the evolution of floral traits in orchids

    Author : Judith Trunschke; Jon Ågren; Nina Sletvold; Allan G. Ellis; Uppsala universitet; []
    Keywords : Among-population variation; Ecotype; Field experiment; Floral evolution; Germination; Local adaptation; Orchidaceae; Platanthera bifolia; Phenotypic selection; Pollination; Reciprocal transplant; Trait manipulation; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Abstract : In this thesis, I combined manipulations of traits and pollination environment with analysis of phenotypic selection to examine causes of variation in strength and mode of selection on floral traits, and I conducted a reciprocal sowing experiment to test for local adaptation in germination success. I tested the following predictions (1) the opportunity for selection, and the strength of pollinator-mediated and net selection increase with increasing pollen limitation, (2) the effects of traits affecting pollinator attraction and traits affecting pollination efficiency are non-additive and this leads to pollinator-mediated correlational selection, (3) the effects of spur length on pollen removal, pollen receipt, and female fitness differ between populations with short-tongued and populations with long-tongued pollinators, and (4) local adaptation at the stage of germination contributes to the maintenance of ecotypes growing in grasslands and woodlands, respectively. READ MORE

  5. 3. Genome Evolution and Niche Differentiation of Bacterial Endosymbionts

    Author : Kirsten Maren Ellegaard; Siv Andersson; Andrés Moya; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; niche; habitat; endosymbiont; gut microbiome; honey bee; Wolbachia; comparative; genomics;

    Abstract : Most animals contain chronic microbial infections that inflict no harm on their hosts. Recently, the gut microflora of humans and other animals have been characterized. However, little is known about the forces that shape the diversity of these bacterial communities. READ MORE

  6. 4. Selection and Floral Evolution in Platanthera bifolia and P. chlorantha (Orchidaceae)

    Author : Johanne Maad; Charles B. Fenster; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Evolution; phenotypic selection; male function hypothesis; mating systems; floral shifts; orchids; pollination; moth pollinators; Platanthera.; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; systematisk botanik; Systematic Botany;

    Abstract : Natural selection mediated by pollinators has influenced the evolution of floral diversity of the flowering plants (angiosperms). The scope of this thesis was to study: 1) phenotypic selection, 2) mating systems, and 3) floral shifts involved in plant speciation. Model plant species were Platanthera bifolia and P. chlorantha (Orchidaceae). READ MORE

  7. 5. Genetic Variation and Evolution of Floral Display in Primula farinosa

    Author : Camille Madec; Jon Ågren; Johan Ehrlén; Richard Ennos; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; natural selection; flowering time; population differentiation; local adaptation; male reproductive success;

    Abstract : In this thesis, I combine molecular analyses, common-garden and field experiments to examine how evolutionary and ecological processes influence patterns of genetic variation among and within populations of the declining, insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically I examined 1) whether genetic diversity at neutral marker loci was related to habitat fragmentation and habitat stability, 2) whether floral display and flowering time were more strongly differentiated among populations than were putatively neutral marker loci, 3) whether adaptive population differentiation could be detected on a local spatial scale, and 4) whether floral display differentially affected male and female reproductive success. READ MORE