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

Allopolyploid origin of highly invasive Centaurea stoebe s.l. (Asteraceae)

Mráz, Patrik ; Garcia-Jacas, Núria ; Gex-Fabry, Emilie ; Susanna, Alfonso ; Barres, Laia ; Müller-Schärer, Heinz

In: Molecular Phylogenetics and Evolution, 2012, vol. 62, no. 2, p. 612–623

Spotted knapweed (Centaurea stoebe) occurs from Western Asia to Western Europe both as diploid and tetraploid cytotypes, predominantly in single-cytotype populations with higher frequency of diploid populations. Interestingly, only tetraploids have been recorded so far from its introduced range in North America where they became highly invasive. We performed phylogenetic and network analyses of...