A Molecular Phylogeny for the Genus Coccoloba (Polygonaceae) with an Assessment of Biogeographic Patterns

Abstract

Abstract—Species in the genus Coccoloba are trees, shrubs, and lianas present in low elevation tropical and sub-tropical forests. Since 1756, well over 400 taxa have been described for Coccoloba. Coccoloba species are natively distributed throughout the New World in a variety of habitats. Despite being distributed throughout the Neotropics, the concentration of Coccoloba species in a given area varies considerably, with four centers of diversity for the genus: southern and coastal Brazil, the West Indies, Mesoamerica, and Amazonia. We here present the first molecular phylogeny of Coccoloba and use this phylogeny to investigate geographic patterns of diversity within the genus. The topology of the phylogeny and the closest related genera to Coccoloba suggest a Mesoamerican origin for the genus. The South American species are recovered as the crown group of the phylogeny with one instance of a separate migration event from Mesoamerica to South America. Coccoloba species in Mesoamerica and the Caribbean show little to no geographic pattern to their diversification. Mesoamerica and the Caribbean are best considered as one phytogeographic region for Coccoloba.

Phylogenomics and evolutionary diversification of the subfamily Polygonoideae

“…The sampled species of all species in the total family clustered into seven clades, and phylogenetic relationships of all subclades were well resolved. The phylogenetic relationships between these clades are largely consistent with previous reports (Sanchez et al, 2009, 2011; Burke et al, 2010, 2011; Burke & Sanchez, 2011; Schuster et al, 2013; Koenemann & Burke, 2020) but with increased levels of support. Except for the single clade for the Eriogonoideae, the other six clades were recovered for the Polygonoideae.…”

“…These different habits were used to classify different tribes (Li et al, 2003; Burke et al, 2010; Burke, 2011; Burke & Sanchez, 2011). Two major subfamilies, Eriogonoideae and Polygonoideae and several subtribes within each subfamily, for example, Brunnichieae, Coccolobeae, Triplareae, and Eriogoneae for the former (e.g., Burke & Sanchez, 2011) while Polygoneae, Calligoneae, Pteroxygoneae, and Fagopyreae for the latter, have been established (e.g., Haraldson, 1978; Brandbyge, 1993; Sanchez et al, 2009, 2011; Burke et al, 2010; Burke, 2011; Burke & Sanchez, 2011; Koenemann & Burke, 2020). Many species of the subfamily Polygonoideae are economically important, providing grains for both humans and livestock (i.e., buckwheat), animal forage, horticultural crops, and local medicine (Decraene & Akeroyd, 1988; Huxley & Warner, 1992; Qaiser, 2001; Li et al, 2003; Sanchez et al, 2009).…”

“…A robust phylogeny is necessary to understand evolutionary diversification of Polygonoideae which occur mainly in the North Hemisphere. In the past two decades, numerous phylogenetic analyses have been undertaken for this subfamily, mostly based on plastome genes (i.e., mat K, rbc L, and ndh F) and inter‐gene non‐coding fragments ( trn L‐ trn F) and nuclear sequences (mainly ITS and LEAFY ) (Frye & Kron, 2003; Sanchez & Kron, 2008; Sun et al, 2008; Galasso et al, 2009; Sanchez et al, 2009, 2011; Tian et al, 2009; Burke et al, 2010; Tavakkoli et al, 2010; Burke, 2011; Burke & Sanchez, 2011; Sun & Zhang, 2012; Schuster et al, 2013; Tavakkoli et al, 2015; Koenemann & Burke, 2020). Several tribes and a few genera have been found to be monophyletic (Frye & Kron, 2003; Sanchez & Kron, 2008; Galasso et al, 2009; Schuster et al, 2013) and phylogenetic relationships between tribes or deep clades (Chen et al, 2021) have also been discerned in this subfamily but with weak support (Sanchez et al, 2009, 2011).…”

A new phylogeny of Rumex (Polygonaceae) adds evolutionary context to the diversity of reproductive systems present in the genus

“…For plastid marker selection, we screened multiple markers that had previously been used in Polygonaceae reconstruction ( Burke et al 2010 ; Burke and Sanchez 2011 ; Koenemann and Burke 2020 ). We selected markers that both showed sufficient variation across the genus and were easily amplified for most taxa.…”