Université de Fribourg

Anthropogenic disturbance as a driver of microspatial and microhabitat segregation of cytotypes of Centaurea stoebe and cytotype interactions in secondary contact zones

Mráz, Patrik ; Španiel, Stanislav ; Keller, Andreas ; Bowmann, Gillianne ; Farkas, Alexandre ; Šingliarová, Barbora ; Rohr, Rudolf P. ; Broennimann, Olivier ; Müller-Schärer, Heinz

In: Annals of Botany, 2012, p. -

Background and Aims: In a mixed-ploidy population, strong frequency-dependent mating will lead to the elimination of the less common cytotype, unless prezygotic barriers enhance assortative mating. However, such barriers favouring cytotype coexistence have only rarely been explored. Here, an assessment is made of the mechanisms involved in formation of mixed-ploidy populations and coexistence...

Université de Fribourg

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

Mráz, Patrik ; Bourchier, Robert S. ; Treier, Urs A. ; Schaffner, Urs ; Müller-Schärer, Heinz

In: International Journal of Plant Sciences, 2011, vol. 172, no. 3, p. 386-402

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...