Molecular data and ploidal levels indicate several putative allopolyploidization events in the genus Potentilla (Rosaceae)

• Several naturally occurring hybrids in Potentilla (Rosaceae) have been reported, but no molecular evidence has so far been available to test these hypotheses of hybridization. We have compared a nuclear and a chloroplast gene tree to identify topological incongruences that may indicate hybridization events in the genus. Furthermore, the monophyly and phylogenetic position of the proposed segregated genera Argentina, Ivesia and Horkelia have been tested. The systematic signal from the two morphological characters, style- and anther shape, has also been investigated by ancestral state reconstruction, to elucidate how well these characters concur with the results of the molecular phylogenies. Six major clades, Anserina, Alba, Fragarioides, Reptans, ivesioid Potentilleae and Argentea, have been identified within genus Potentilla. The ivesioid Potentilleae (Horkelia, Ivesia and Horkeliella) form a monophyletic group nested within Potentilla. Furthermore, the origin of the proposed segregated genus Argentina (the Anserina clade) is uncertain but not in conflict with a new generic status of the group. We also found style morphology to be an informative character that reflects the phylogenetic relationships within Potentilla. Four well supported incongruences were found between the nuclear and the chloroplast phylogenies, where the involved taxa were polyploids. However, further investigations using low copy molecular markers are required to infer the phylogeny of these species and to test the hypothesis of hybrid origin.

Ämnesord

NATURVETENSKAP  -- Biologi -- Biologisk systematik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biological Systematics (hsv//eng)

Nyckelord

Allopolyploidy

Potentilla

molecular phylogeny

Rosaceae

hybridization

Systematics and phylogenetics

Systematik och fylogeni

systematisk botanik

Systematic Botany

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)