The duplicated nuclear gene CHS was used to position three problematic genera within Gesneriaceae. CHS is duplicated in all lineages and forms extensive orthologous-paralogous trees making the placement of genera within the family distinct. Two genera of the tribe Coronanthereae (Sarmienta and Rhabdothamnus) are a monophyletic group within the Gesnerioideae subfamily and this clade is sister to a large orthologous-paralogous subtree containing the majority of new world genera This placement suggests that Coronanthereae does not merit standing as a subfamily but is a tribe circumscribed within Gesnerioideae. The monotaxic tribe Titanotricheae (Titanotrichum) lies between the Coronanthereae and sister to the rest of the new world genera.
Placement of Three Problematic Genera of Gesneriaceae based on Chalcone Synthase (CHS) a Duplicated Nuclear Gene.
Publication: Botanical Society of America (poster presentation)
Genera: Rhabdothamnus, Sarmienta, Titanotrichum