Université de Fribourg

Allozyme variation in diploid, polyploid and mixed-ploidy populations of the Pilosella alpicola group (Asteraceae): relation to morphology, origin of polyploids and breeding system

Šingliarová, Barbora ; Chrtek, Jindřich ; Plačková, Ivana ; Mráz, Patrik

In: Folia Geobotanica, 2011, p. -

The Pilosella alpicola group includes four species (P. alpicola s.str., P. ullepitschii, P. rhodopea and P. serbica) with allopatric distributions (Alps, Balkans, Carpathians) and contrasting cytotype patterns (diploid, diploid-polyploid and polyploid species). Whereas diploid taxa (P. ullepitschii and P. serbica) reproduce sexually, the mode of...

Université de Fribourg

Interspecific hybridization in the genus Hieracium s. str.: evidence for bidirectional gene flow and spontaneous allopolyploidization

Mráz, Patrik ; Chrtek, Jindřich ; Fehrer, Judith

In: Plant Systematics and Evolution, 2011, vol. 293, p. 237–245

Although reticulation has indisputably played an important role in the evolutionary history of the genus Hieracium s. str. (Asteraceae), convincingly documented cases of recent interspecific hybridization are very rare. Here we report combined evidence on recent hybridization between two diploid species, Hieracium alpinum and H. transsilvanicum. The hybrid origin of...

Université de Fribourg

Geographical parthenogenesis, genome size variation and pollen production in the arctic-alpine species Hieracium alpinum

Mráz, Patrik ; Chrtek, Jindřich ; Šingliarová, Barbora

In: Botanica Helvetica, 2009, vol. 119, no. 1, p. 41-51

Hieracium alpinum L. (Asteraceae) is an arctic-alpine species distributed throughout Europe with both diploid and triploid cytotypes. We determined the ploidy levels of plants from 23 populations from Austria, Bosnia and Herzegovina, Finland, Italy, Norway, Romania, Slovakia, Switzerland and Ukraine. Data showed a non-overlapping pattern of cytotype distribution: sexually reproducing diploids (2n...