Filogenia, Biogeografia e Taxonomia de Pradosia (Sapotaceae, Chrysophylloideae)

Abstract

The genus Pradosia (Sapotaceae, Chrysophylloideae) comprises 23 species that vary in habit from geoxylic shrubs to medium-sized and tall canopy trees up to 35 m. The genus is confined to South America, one of which also extends into Panama and Costa Rica. The species are distributed across a wide variety of habitats, including savannas and evergreen to deciduous forests in the Amazon region, the Brazilian Atlantic coast, and the Andes. Previous studies including a few species of Pradosia have indicated that the genus is monophyletic, provided that the African species P. spinosa, is excluded. This work presents the results of a new phylogenetic study of Pradosia, with a broader species sampling and aimed to: (1) produce a phylogenetic hypothesis for the genus Pradosia using molecular data; (2) estimate species divergence times and biogeographical history; (3) reconstruct the evolution of some morphological traits that have been considered useful in distinguishing species within the genus; (4) investigate the evolution of habitat preference; (5) provide a taxonomic update to the species. These objectives correspond to the three chapters of the present thesis. The first chapter includes a molecular phylogeny of Pradosia based on the molecular markers ITS and ETS. The resulting phylogenetic hypothesis was used to infer the generic biogeographical history of the genus, explore the evolution of morphological characters, and habitat preferences. The second chapter presents the novelties in Pradosia, with description of new species. Lastly, the third chapter presents a synopsis of the species, a review of the species geographical distributions, and a new key followed by a short morphological description, as well as notes regarding species circumscriptions and information obtained in field.