Phylogenetic Placement and Circumscription of Tribes Inuleae s. str. and Plucheeae (Asteraceae): Evidence from Sequences of Chloroplast Gene ndhF

Abstract

DNA sequences from chloroplast gene ndhF were investigated in 15 species in tribes Inuleae Cass. s. str., Plucheeae (Benth.) A. Anderb., and Gnaphalieae Benth. (Asteraceae) and combined with 90 ndhF sequences from GenBank to evaluate the circumscription of the putative sister tribes Inuleae and Plucheeae. The data were subjected to phylogenetic analysis using parsimony jackknifing. The results are presented in a cladogram and discussed in comparison to previous analyses of both molecular and morphological data. The interpretations of specific diagnostic characters are also discussed. The majority of genera from Inuleae s. str. and Plucheeae comprise a monophyletic group, sister to the Heliantheae s. l.–Blepharispermum–Athroisma group. The genera of the Gnaphalieae belong to a different monophyletic group within the family that also includes tribes Anthemideae, Astereae, and Calenduleae. Within the Inuleae–Plucheeae complex, two well-supported subclades were identified, one corresponding to the Inuleae s. str. and the second to the Plucheeae. Three genera, Antiphiona, Pegolettia, and Geigeria, were outside of both tribes and were part of an unresolved polytomy at the base of the Inuleae–Plucheeae clade. Anisopappus, hitherto considered a member of Inuleae s. str., was found to be part of the Heliantheae–Athroisma–Blepharispermum clade. As discussed, the results of previous phylogenetic analyses, presenting Anisopappus as the basalmost taxon of Inuleae s. str., may be due to inadequate sampling.