Phylogeny and systematics of the western Mediterranean Vella pseudocytisus-V. aspera complex (Brassicaceae)

Authors: VIOLETA I. SIMÓN-PORCAR, ERNESTO PEREZ-COLLAZOS, PILAR CATALAN

Abstract: The evolution and taxonomy of the core members of subtribe Vellinae (Brassicaceae), comprising Vella aspera, V. Bourgeana, and V. Pseudocytisus, is still poorly known. We reconstructed the evolutionary relationships among these taxa and other Vellinae and close Brassicaceae using nuclear ITS and plastid trnTF phylogenies, and analyzed the phenotypic traits that differentiate the infraspecific ranks of V. Pseudocytisus. Our phylogenetic analyses show: i) an early divergence of Succowia within the Brassiceae-Sisymbrieae sensu lato clade; ii) the nested positions of Vella bourgeana (syn. Euzomodendron bourgaeanum) and V. Aspera (syn. Boleum asperum) within the Vella clade; and iii) the split of 5 lineages within the V. Pseudocytisus clade (NW African subspecies glabrata 2x; SE Spain subspecies pseudocytisus 2x; C Spain subspecies pseudocytisus 4x; NE Spain subspecies paui 4x Alfambra Valley; and NE Spain subspecies paui 4x Turia Valley). Phenotypic traits support the differentiation of the diploid and tetraploid cytotypes of V. Pseudocytisus subsp. Pseudocytisus. Our data support the separation of Succowia from the Vellinae and the erection of a new subspecies within V. Pseudocytisus (Vella pseudocytisus subsp. Orcensis subsp. Nov.). They also corroborate the inclusion of Boleum and Euzomodendron within Vella.

Keywords: Bayesian and parsimony phylogenies, Bayesian relaxed-clock dating, plastid and nuclear DNA sequences (ITS, trnTL, trnLF), taxonomy, Vellinae

Full Text: PDF