Origin and maintenance of intrapopulational cytotype mixture in Senecio carniolicus in the Eastern Alps

Introduction
Polyploidy is considered a major driving force for speciation, and most angiosperms are believed to be at least anciently polyploid. The high mountain plant Senecio carniolicus (Asteraceae), which is endemic to the Eastern Alps and the Carpathians is an excellent example of ongoing polyploid speciation and provides insights into many of the underlying mechanisms and processes. It occurs mainly on siliceous bedrock in alpine to subnival grasslands, moraines and stable screes, as well as rock habitats up to 3300 m. Recent investigations revealed three major cytotypes (2x, 4x, 6x) with occasional ploidy irregularities. There is accumulating evidence for morphological, ecological and reproductive separation.

Research Questions

  • Are polyploid cytotypes of single or multiple origin?
  • How were the distribution patterns influenced during the Pleistocene glaciations? Are migration routes detectable?
  • How strong are the crossing barriers between cytotypes and how are they mediated?
  • Is there evidence for habitat segregation between cytotypes?
  • Do cytotype differ in flowering time, leading to precygotic reproductive isolation? If so, are the differences genetically or environmentally determined?
  • Do crosses between cytotypes yield viable seeds? If yes, are there postzygotic isolation mechanisms?
  • If hybrids do occur, are they less fit compared to their parental cytotypes?
  • Are there significant morphological differences between cytotypes?

crossings-senecio

fieldworksenecio-carniolicus

For more information, visit the homepage of the project at the University of Vienna.[Link]

Funding
Austrian Science Fund (FWF), P-20736 (PI: Peter Schönswetter [until July 2010])

External Collaborators
Several at the Faculty Centre Botany of the University of Vienna.[Link]
Jan Suda, Charles University, Prague and Czech Academy of Sciences, Pruhonice.[Link]

Personnel involved
Peter Schönswetter

Nach oben scrollen