Molecular differentiation between coexisting species of Taraxacum sect. Erythrosperma (Asteraceae) from populations in south-east and west Germany

摘要

The present study focuses on the genetic differentiation between six coexisting species of Taraxacum sect. Erythrosperma. Twenty-six individuals of T rubicundum, T brachyglossum, T tortilobum, T lacistophyllum, T parnassicum and T scanicum were sampled at 14 locations in south-east (Bavaria) and west Germany (Eifel). Using random amplified polymorphic DNA (RAPD) analysis 139 fragments were amplified. Nineteen of these were found to be species specific. The level of polymorphic bands within the different Taraxacum species varied between 0% and 15.8%. An analysis of molecular variance (AMOVA) revealed strong differentiation between the investigated species: 14.3% of the molecular variance were found within the species, while 85.7% of the genetic variability was observed between the species. However, a geographical differentiation between the different regions could not be observed. All analysed species were clearly separated from each other in a cluster analysis using the neighbour joining technique. The observed strong genetic differentiation between the Taraxacum species clearly supports the agamospecies concept of Taraxacum sect. Erythrosperma, which is at present mainly based on morphological and cytological criteria