02 de mayo de 2021

PHYLOGEOGRAPHIC RELATIONSHIPS AMONG SCANDENT SPECIES OF PENTACALIA, MONTICALIA AND DENDROPHORBIUM (COMPOSITAE: SENECIONEAE)

Pentacalia, a Neotropical genus of about 100
species has shown in previous molecular
phylogenetic studies to be paraphyletic and
polyphyletic. The present study assesses
this conclusion using morphology and new
sequences of ETS, ITS and trnL regions of
species from isolated areas of Northern
Andes (e.g. Sierra Nevada de Santa Marta),
and proposes a classification of the Colombian
species into 4 groups elevated to the rank
of sections. A morphological matrix is used
to explore differences between the clades
resulting of maximum parsimony analysis,
and allows to evaluate
infrageneric groups proposed by J. Cuatrecasas.
Reproductive and vegetative characters such
as habit and number of ligules are studied in
the light of our molecular topologies, and a
biogeographical framework for the colonization
and up/down migrations of Pentacalia sensu lato
species in the Andes is presented. Evolutionary
relationships among Pentacalia sensu lato and
closely related genera such as Monticalia and
Dendrophorbium, are discussed. Phylogenetic
trees for Senecioninae suggest independent
pathways of evolution during Andean species
establishment, with plasticity in growing forms
resulting in transformations from erect to
scandent forms in several independent cases.

Publicado el mayo 2, 2021 11:29 TARDE por fgarciay fgarciay | 0 comentarios | Deja un comentario

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