Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Selection and Floral Evolution in Platanthera bifolia and P. chlorantha (Orchidaceae)
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Evolutionary Biology.
2002 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

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). These orchids are moth-pollinated, strictly co-sexual (bisexual flowers), and produce a spike that displays 10-20 white flowers.

I explored the influence of characters on plant fitness by using multiple linear regressions. Pollen removal (male fitness) and fruit set (female fitness) increased with more flowers per plant in three P. bifolia populations. There was selection towards longer spurs in a dry year when average spur length was shorter than in normal-wet years. Female function was sensitive to drought, which enabled an application of the male function hypothesis of floral evolution (Bateman's principle). The results show that selection may vary between populations, years, and sex-functions.

I examined inbreeding by estimating levels of geitonogamy (self-pollination between flowers of an individual) with an emasculation method in two P. bifolia populations. Geitonogamy did not vary with inflorescence size. Levels of geitonogamy was 20-40% in the smaller, but non-significant in the larger population. This may relate to lower number of possible mates and pollinator activity in the smaller population.

Platanthera bifolia exhibits the ancestral character state of tongue-attachment of pollinia on the pollinator. Its close relative P. chlorantha attaches its pollinia onto the pollinator's eyes. To explore the mechanism of a floral shift, pollination efficiency and speed was compared between the two species. The results showed no differences in pollination efficiency, but P. chlorantha had faster pollen export and import. Efficiency of pollination in terms of speed may cause floral shifts, and thus speciation.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 2002. , p. 26
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 685
Keywords [en]
Developmental biology, Evolution, phenotypic selection, male function hypothesis, mating systems, floral shifts, orchids, pollination, moth pollinators, Platanthera.
Keywords [sv]
Utvecklingsbiologi
National Category
Developmental Biology
Research subject
Systematic Botany
Identifiers
URN: urn:nbn:se:uu:diva-1754ISBN: 91-554-5226-4 (print)OAI: oai:DiVA.org:uu-1754DiVA, id: diva2:161329
Public defence
2002-03-08, Lindahl Hall, Norbyvägen 18A, Uppsala, 10:00
Opponent
Available from: 2002-02-13 Created: 2002-02-13Bibliographically approved
List of papers
1. Phenotypic selection in hawkmoth-pollinated Platanthera bifolia: Targets and fitness surfaces
Open this publication in new window or tab >>Phenotypic selection in hawkmoth-pollinated Platanthera bifolia: Targets and fitness surfaces
2000 In: Evolution, Vol. 54, no 1, p. 112-123Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-89658 (URN)
Available from: 2002-02-13 Created: 2002-02-13Bibliographically approved
2. Patterns of selection vary with resources and differ between sex-functions in Platanthera bifolia (Orchidaceae)
Open this publication in new window or tab >>Patterns of selection vary with resources and differ between sex-functions in Platanthera bifolia (Orchidaceae)
Manuscript (Other academic)
Identifiers
urn:nbn:se:uu:diva-89659 (URN)
Available from: 2002-02-13 Created: 2002-02-13 Last updated: 2010-01-13Bibliographically approved
3. Influence of population size and inflorescence display on geitonogamy in Platanthera bifolia (Orchidaceae)
Open this publication in new window or tab >>Influence of population size and inflorescence display on geitonogamy in Platanthera bifolia (Orchidaceae)
Manuscript (Other academic)
Identifiers
urn:nbn:se:uu:diva-89660 (URN)
Available from: 2002-02-13 Created: 2002-02-13 Last updated: 2010-01-13Bibliographically approved
4. On the mechanism of floral shifts in speciation: Gained pollination efficiency from tongue- to eye-attachment of pollinia in Platanthera (Orchidaceae)?
Open this publication in new window or tab >>On the mechanism of floral shifts in speciation: Gained pollination efficiency from tongue- to eye-attachment of pollinia in Platanthera (Orchidaceae)?
Manuscript (Other academic)
Identifiers
urn:nbn:se:uu:diva-89661 (URN)
Available from: 2002-02-13 Created: 2002-02-13 Last updated: 2010-01-13Bibliographically approved

Open Access in DiVA

fulltext(1777 kB)2735 downloads
File information
File name FULLTEXT01.pdfFile size 1777 kBChecksum MD5
5a909b00e56b8b0c013b82620e5f560f5cd1f27155a2b475ea792d237525e4c77895f87c
Type fulltextMimetype application/pdf
Buy this publication >>

By organisation
Department of Evolutionary Biology
Developmental Biology

Search outside of DiVA

GoogleGoogle Scholar
Total: 2735 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 950 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf