Sökning: "Platanthera bifolia"

Hittade 4 avhandlingar innehållade orden Platanthera bifolia.

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

   Författare :Johanne Maad; Charles B. Fenster; Uppsala universitet; []
   Nyckelord :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;

   Sammanfattning : 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). LÄS MER

3. 2. Evolution of Spur Length in a Moth-pollinated Orchid

   Författare :Elin Boberg; Jon Ågren; W. Scott Armbruster; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Platanthera bifolia; floral evolution; natural selection; pollination; spur length; population differentiation; divergent selection; disruptive selection; reproductive isolation; Biology; Biologi; Ecological Botany; Ekologisk botanik;

   Sammanfattning : There is considerable evidence that pollinator shifts can explain many differences in flower morphology between closely related plant species, but the extent to which pollinator shifts can explain the maintenance of among-population variation in floral traits within species is poorly known. In this thesis, I combined comparative and experimental approaches to examine the evolution of floral traits in the moth-pollinated orchid Platanthera bifolia. LÄS MER

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

   Författare :Judith Trunschke; Jon Ågren; Nina Sletvold; Allan G. Ellis; Uppsala universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

5. 4. Odour-mediated nectar foraging in the silver Y moth, Autographa gamma

   Författare :Dainius Plepys; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; predation risk; Noctuidae; Lepidoptera; flight tunnel; GC-EAD; single sensillum; sprayer; ultrasound; floral volatiles; attraction; foraging; mate-finding; lilac aldehydes; olfactory receptor neurones; Ecology; Ekologi; Chemistry; Kemi;

   Sammanfattning : It is well established that floral odours play a significant role in the nectar foraging behaviour in Lepidoptera and other insect orders. Floral odour may elicit searching, alighting and feeding behaviours alone or in concert with visual stimuli. LÄS MER