Université de Fribourg

Allopatric distribution, ecology and conservation status of the Pilosella alpicola group (Asteraceae)

Šingliarová, Barbora ; Šuvada, Róbert ; Mráz, Patrik

In: Nordic Journal of Botany, 2013, vol. 31, no. 1, p. 122–128

The Pilosella alpicola group comprises four morphologically distinct and geographically vicariant alpine taxa. We performed a thorough herbarium revision and literature survey to infer their distributional pattern(s). Pilosella alpicola s.s. occurs in the Alps in two disjunct areas: the Swiss Valais Alps and the Italian Dolomites. Historical records come also from the Austrian Alps (Gurktaler...

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 of...

Université de Fribourg

Biosystematic study of the diploid-polyploid Pilosella alpicola group with variation in breeding system: Patterns and processes

Šingliarová, Barbora ; Hodálová, Iva ; Mráz, Patrik

In: Taxon, 2011, vol. 60, no. 2, p. 450-470

Members of the Pilosella alpicola species group (Asteraceae) are distributed throughout the alpine region of the European mountains (Alps, Carpathians, Balkan mountains). Like other Pilosella species groups (Hieracium subg. Pilosella ), the taxonomy and species' relationships are poorly understood mostly due to widespread facultative apomixis, frequent hybridization and polyploidization—the...

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

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...

Université de Fribourg

A taxonomic revision of the Pilosella alpicola group in the Carpathians

Šingliarová, Barbora ; Mráz, Patrik

In: Preslia, 2009, vol. 81, p. 23-41

A taxonomic study of the Pilosella alpicola group growing in the Carpathians revealed the presence of two morphologically distinguishable taxa: P. ullepitschii (Błocki) Szeląg and P. rhodopea (Griseb.) Szeląg. While P. ullepitschii is endemic to the Carpathians, P. rhodopea is a Balkan subendemic with two isolated localities in the Southern Carpathians (Mt Cozia and Mt Zmeuretu). The core area...

Université de Fribourg

Chromosome numbers and mode of reproduction in Picris hieracioides s.l. (Asteraceae), with notes on some other Picris taxa

Slovák, Marek ; Šingliarová, Barbora ; Mráz, Patrik

In: Nordic Journal of Botany, 2007, vol. 25, no. 3-4, p. 238 - 244

Chromosome numbers for 88 plants of Picris hieracioides s.l. originating from 32 localities from Austria, Andorra, Croatia, France, Germany, Hungary, Italy, Slovakia and Spain are reported. All analysed plants were diploid, with 2n=2x=10. In addition to P. hieracioides s.l., we also found diploidy (2n=2x=10) in P. nuristanica from Kirgizia and P. japonica from Japan. Our data confirmed previously...