Phylogenetic relationships, taxonomy, and morphological evolution in Dipsacaceae (Dipsacales) inferred by DNA sequence data

Abstract

AbstractA phylogenetic study of Dipsacaceae, a Mediterranean­centered clade in the Dipsacales, was conducted using nuclear ITS and three chloroplast markers (atpB ­ rbcL, trnL­ trnF, trnSUGA­ trnGGCC). This is the first molecular study to assess Dipsacaceae phylogeny in detail, and includes representatives from all major subclades. Maximum parsimony, maximum likelihood, and Bayesian analyses were carried out on the ITS and plastid datasets separately and in combination. For the most part, the ITS and plastid datasets resulted in similar topologies, and the combined data yielded a well­resolved estimate of Dipsacaceae phylogeny. A small Asian clade composed of Bassecoia and Pterocephalodes hookeri is resolved as sister to the rest of Dipsacaceae. Scabioseae s. str. (Scabiosa, Sixalix, Pterocephalus s. str., Lomelosia , Pycnocomon) and a "Dipknautid" clade (Dipsacus, Cephalaria, Knautia, Pterocephalidum, Succisa, Succisella, Pseudoscabiosa) form the two major lineages within Dipsacaceae. Most of the previously recognized genera are recovered as monophyletic, with the exception of Pycnocomon, which is nested within Lomelosia. We discuss the taxonomic implications of these results and their significance for understanding character evolution, particularly of the epicalyx in relation to seed dispersal.