| Abstract Detail
The flora of Madagascar: uncovering mechanisms for diversification Skema, Cynthia [1]. Dombeya as a case study for the diversification of the flora of Madagascar: Dombeya section Hilsenbergia (Malvaceae). Of the roughly 206 species in the paleotropical genus Dombeya, around 173 are endemic to Madagascar and they occur throughout the island, making Dombeya an ideal case study for understanding diversification processes of the flora of Madagascar. Characterized by long staminal tubes and pendulous inflorescences, Dombeya section Hilsenbergia presents a morphologically cohesive group in which to begin this study. The five species in this section occur primarily in the (sub)humid forest along the length of Madagascar and in the Comoros. Molecular data, as of yet, provide no information about the monophyly, or lack thereof, of the section due to a lack of resolution. A nuclear ribosomal marker (ITS) presents evidence for two species pairs (D. hilsenbergii + D. hafotsy; D. baronii + D. wallichii), relationships which are supported by morphology. Plastid markers provide evidence of widespread plastid introgression, with clades reflecting gross geographic provenance of individuals rather than species designations. A series of field collections from Vohiparara (Fianarantsoa Province) suggest the possibility of hybrid zones in the section, which may account for gene flow between the overlapping species (D. baronii, D. cannabina, D. hilsenbergii). Analysis of multiple physical and biological factors (e.g., elevation, aspect, phenology, bioclimatic variables) revealed some interspecific differentiation, but also overlap among some species within the section. Log in to add this item to your schedule
1 - Morris Arboretum Of The University Of Pennsylvania, 100 E. Northwestern Ave., Philadelphia, PA, 19119, United States
Keywords: Madagascar diversification Hybridization Dombeya Malvaceae.
Presentation Type: Colloquium Presentations Session: C08, The flora of Madagascar: uncovering mechanisms for diversification Location: 101/Mayo Civic Center Date: Tuesday, July 24th, 2018 Time: 3:45 PM Number: C08009 Abstract ID:632 Candidate for Awards:None |