Thompsonella and the “Echeveria group” (Crassulaceae): phylogenetic relationships based on molecular and morphological characters

Abstract

Broad phylogenetic analyses of Crassulaceae have retrieved a large clade comprising as much as one‐third of the species diversity present in the family as a whole. This so‐called Acre clade (Sedoideae) includes familiar genera such as Echeveria, Graptopetalum, and Thompsonella, and while it is consistently recovered in studies at the family level, relationships within the clade as well as the monophyly of many of the constituant genera have yet to be established. Results of a phylogenetic study of a genus within the Acre clade, Thompsonella, are here reported. Morphological evidence was gathered and molecular (nuclear ETS and ITS) DNA sequences were generated for forty‐seven taxa from the Acre clade, including all recognized members of Thompsonella. Parsimony analysis of the combined data retrieved Thompsonella as a monophyletic group and retrieved species in Graptopetalum, Thompsonella, Echeveria, Pachyphytum and Sedum sect. Pachysedum in a clade; this group was previously identified as the “Echeveria group”. Results indicate that only a few genera in the Acre clade are monophyletic and that to establish their generic limits further sampling mainly in the large Echeveria and Sedum genera is needed. Results from morphological and molecular analyses disagree in the position of T. mixtecana. However, an additional restricted analysis performed solely with cpDNA (rps16) placed this species within Thompsonella, suggesting a hybrid origin.

Phylogeny, Biogeography, and Evolution of Edaphic Association in the European OreophytesSempervivumandJovibarba(Crassulaceae)

“…lished sequences of IGS and the rps16-intron are unequally distributed in the family (Carrillo-Reyes et al 2009). Therefore, in order to obtain divergence time estimates for our phylogeny, we performed molecular dating on two family-wide data sets.…”

“…First, we obtained selected matK sequences of Crassulaceae ( Johnson and Soltis 1995;Fishbein et al 2001;Mort et al 2001Mort et al , 2002Schaefer et al 2011; various barcode projects and unpublished data) as well as sequences of selected outgroup families (Fishbein et al 2001;Moody and Les 2007) from GenBank. ITS sequences were collected in the same way (Gehrig et al 2001;Mort et al 2002;Acevedo-Rosas et al 2004;Mayuzumi and Ohba 2004;Schultheis and Donoghue 2004;Moody and Les 2007;Carrillo-Reyes et al 2008, 2009de Lange et al 2008;Vargas and García 2008;Gao et al 2012;Xiang et al 2012; various barcode projects and unpublished data). As alignment across this large sample was problematic in the ITS1 and ITS2 spacer regions, we pruned the alignment and used only the 5.8S ribosomal gene and those parts of the spacer regions that contained no indels 13 bp.…”

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“…En cambio, en la presente investigación se obtuvieron 594 bandas, de las cuales el 99 % fueron polimórficas. Carrillo-Reyes et al (2008) realizaron un trabajo para identificar grupos monofiléticos para esclarecer si Altamiranoa y Villadia deben reconocerse como géneros independientes, argumentando que a Altamiranoa la dividieron en dos grupos, Subcampanulatae y Gamopetalae pero después vieron la variabilidad de la inflorescencia en otros géneros de Crassulaceae y propusieron la fusión de ambos taxones bajo el nombre de Villadia; posteriormente debido a una errónea interpretación de las láminas de los tipos nomenclaturales de Villadia y Thomsonella Britton & Rose, fue entonces que decidieron que el nombre legitimo para Thompsonella era Villadia y se transfirió a todas las especies de Villadia a Altamiranoa; pero en 1940 detectaron esta equivocación y se separó a Thompsonella de Villadia y Altamiranoa.…”

“…Carrillo- Reyes et al (2008) concluyen que su análisis combinado muestra igualmente numerosas relaciones no resueltas y escasos grupos con soporte. Entonces consideran que debido a que las especies de Sedum se entremezclan con las de todos estos géneros, además de que otras se posicionan en grupos independientes, es necesario primero definir el límite y la composición del resto de los taxones.…”

“…mention that the "Acre clade" includes a third part of Crassulaceae species, but is riddled with a series of unsolved relations Carrillo-Reyes et al (2008). concluded that their combined analysis also present numerous unsolved relations and scarce groups with support.…”