Abstract
Sapotaceae is a woody family that constitutes an important component of tropical forests. In Amazonia, it is amongst the 10 most representative tree families, where its members are readily recognized by the presence of latex and seeds with a conspicuous scar (hilum). Overall, the combination of characters beyond seeds has been useful in recognizing the genera of Sapotaceae. Here, we explored seedling morpho-functional traits across the most recent phylogenetic hypothesis for neotropical Sapotaceae (clades A-Q). Seeds of eight genera and 34 species were obtained from central Amazonian forests. We monitored at least five seedlings of each species until they had a third leaf node above cotyledons under greenhouse conditions. The combination of emergence (C-cryptocotylar; P-phanerocotylar), position (E-epigeal; H-hypogeal), and cotyledon function (F-foliaceous; R-reserve) was used to classify five groups of seedlings PEF, PER, PHR, CHR, CER, which were mapped onto the phylogeny. We observed four seedling types in 34 taxa (PEF=14, PER=8, PHR/CHR=6 each), which showed strong congruence with sampled clades. PEF is shared amongst sister clades (A-B, F, H, and Chrysophyllum pomiferum). They correspond mostly to genera proposed in the latest treatment Micropholis (A) and Chrysophyllum (H), and others that are expected to be resurrected such as Ragala (B) and Prieurella (F). Within this mentioned group, exceptions are C (Elaeoluma), E (Ecclinusa), and I (possible resurrection of Lucuma) which have PHR, PER, and CHR, respectively. PHR is also shared independently in clades N and Q (Pouteria); PER in K (Pradosia) and M (Pouteria); CHR by Sarcaulus brasiliensis and in L (Chromolucuma), J and O (Pouteria). Seedling types may be informative for most clades, but not sufficient by themselves to support clades that still need internal resolution such as those encompassing Pouteria species. However, they may be considered in combination with other characters in future studies.
Caroline C. Vasconcelos
DSc candidate in Botany
My research interests include taxonomy and systematics (especially neotropical Sapotaceae); spectroscopy as a integrative tools; Amazonian flora; species distribution modelling; floristic studies; and tropical forest ecology.