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Polyploidy in phenotypic space and invasion context: a morphometric study of Centraurea stoebe s.l.

  • Mráz, Patrik Department of Biology, Unit of Ecology and Evolution, University of Fribourg, Switzerland
  • Bourchier, Robert S. Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
  • Treier, Urs A. Department of Biological Sciences, Ecoinformatics and Biodiversity, Aarhus University, Denmark
  • Schaffner, Urs CABI Europe–Switzerland, Delémont, Switzerland
  • Müller-Schärer, Heinz Department of Biology, Unit of Ecology and Evolution, University of Fribourg, Switzerland
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    2011
Published in:
  • International Journal of Plant Sciences. - 2011, vol. 172, no. 3, p. 386-402
Asteraceae
Biological invasion
Flow cytometry
Karyology
Multivariate morphometrics
Polyploidy
Spotted knapweed
English The taxonomy of the Centaurea stoebe complex is controversial. Diploid and tetraploid plants occur in its native European range, but to date only tetraploids have been recorded from its introduced range in North America. We examined morphological differentiation of C. stoebe using multivariate and univariate approaches to clarify the taxonomic status of the known cytotypes. We measured more than 40 morphological traits on plants originating from 78 populations, grown from seed under uniform glasshouse conditions. The ploidy of almost 300 plants from 2 native and 20 introduced populations from Canada was assessed to test for the absence of diploids from North America. Finally, we explored whether postintroduction processes have resulted in phenotypic changes in introduced plants which may have contributed to the invasion success of C. stoebe. Morphometric analyses showed a clear separation of 2x and 4x plants and thus supported recognition of both cytotypes as separate taxa. Differences in the life cycle, the number of florets, the shape of capitula, and the shape of young rosette leaves were the best discriminant characters. Only minor differences were found between native and introduced tetraploids. All plants from the introduced range except for one hexaploid were found to be tetraploid. Rare diploids from Canada were identified as Centaurea diffusa or Centaurea psamogenna.
Faculty
Faculté des sciences et de médecine
Department
Département de Biologie
Language
  • English
Classification
Biological sciences
License
License undefined
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Persistent URL
https://folia.unifr.ch/unifr/documents/302213
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