Taxonomia integrativa para a delimitação e descrição de espécies em Chrysophylloideae neotropical (Sapotaceae)

Abstract

Approximately 1,300 species and 73 genera are currently recognized in Sapotaceae, 21 of which are Neotropical members of the subfamily Chrysophylloideae. Among these are Chromolucuma, Ecclinusa, Lucuma, and Pradosia, which have been studied from different perspectives in this thesis. Given the ongoing systematic changes in the classification of Neotropical Chrysophylloideae, many groups will naturally require further studies to achieve better internal resolution. Considering the representativeness of Chrysophylloideae in Neotropical flora and the importance of taxonomy in understanding biodiversity, this need opens up numerous opportunities for studies aimed at characterizing, classifying, and naming taxa. This thesis follows different paths within the context of the Neotropical Chrysophylloideae, each representing complementary windows for exploring the complexity of the Sapotaceae. In Chapter 1, we focused on exploring species limits in the genus Ecclinusa using an integrated set of morphological, spectral, geographic, and ecological data collected from specimens of biodiversity repositories. At least 31 morphotypes could be recognized within Ecclinusa, 26 of which were discriminated with excellent overall accuracy using the best-performing dataset (traditional morphometry + spectral signatures + geography + ecology). Among the 12 valid species, eight match their current circumscriptions (E. atabapoensis, E. campinae, E. dumetorum, E. lancifolia, E. orinocoensis, E. psilophylla, E. ulei, and potentially E. parviflora). However, the extensive phenotypic variation and numerous morphotypes within the most challenging species (E. bullata, E. guianensis, E. lanceolata, and E. ramiflora) suggest that the diversity within Ecclinusa may be underestimated. We also found a clear geographical disjunction between the populations of Pan-Amazonia and the Atlantic Forest, which may contribute to possible isolation and genetic structuring of lineages. Further, the database compiled in this study will be valuable for future integration with genetic data, enabling more robust tests of species limits, as well as evolutionary and biogeographical hypotheses about Ecclinusa. In Chapter 2, in addition to Ecclinusa, we provide relevant taxonomic contributions for some genera of Chrysophylloideae (Chromolucuma, Lucuma, and Pradosia) through the description of two new species (Ecclinusa nervosa and Chromolucuma brevipedicellata); a note on the morphological complementation of Chromolucuma flavilatex, including an expanded discussion of the systematic potential of seedling characters from a phylogenetic perspective; a necessary new combination, transferring Pouteria kossmanniae to Lucuma kossmanniae in light of recent systematic changes in the generic classification of Chrysophylloideae Neotropical; and a new record of Pradosia ptychandra in a poorly documented area of the Brazilian eastern Amazonia, integrating species distribution modeling. Finally, all these findings are pieces of a larger puzzle, contributing to filling small gaps in our knowledge of Sapotaceae. This not only expanded our understanding of the intrinsic diversity of the genus but also sparked reflections on broader issues related to the taxonomy, evolution, and ecology of the studied groups. Overall, the results presented in this thesis encompass different approaches that, in addition to filling gaps in the taxonomic and morphological knowledge of the Sapotaceae family, highlight the importance of integrative approaches in understanding biological diversity.