A phylogeny of Apiaceae tribe Scandiceae: Evidence from nuclear ribosomal DNA internal transcribed spacer sequences

Abstract

The evolutionary relationships among members of Apiaceae (Umbelliferae) tribe Scandiceae and representatives of all major lineages of Apioideae (including putatively allied Caucalideae) identified in earlier molecular studies were inferred from nucleotide sequence variation in the internal transcribed spacer regions (ITS1 and ITS2) of nuclear ribosomal DNA. In all, 134 accessions representing 18 genera commonly treated in Scandiceae were analyzed. Phylogenies estimated using maximum parsimony and distance methods were generally similar and suggest that: (1) Scandiceae form a well-supported clade, consisting of the genera Anthriscus, Athamanta (in part), Balansaea, Chaerophyllum, Conopodium, Geocaryum, Kozlovia, Krasnovia, Myrrhis, Myrrhoides, Neoconopodium, Osmorhiza, Scandix, Sphallerocarpus, and Tinguarra; (2) Athamanta is polyphyletic, with A. della-cellae allied with Daucus and A. maceclonica placed close to Pimpinella; and (3) Rhabdosciadium and Grammosciadium find affinity with the Aegopodium group of umbellifers, whereas the placement of the monotypic Molopospermum cannot be inferred because of its high sequence divergence. The genus Bubon has been restored with two new combinations, B. macedonicum subsp. albanicum and B. macedonicum subsp. arachnoideum. Scandiceae arise within paraphyletic Caucalideae, the latter comprising two major lineages whose relationships to Scandiceae are not clear. Therefore, a broad treatment of Scandiceae is proposed, with subtribes Scandicinae, Daucinae, and Torilidinae (the latter two representing the Daucus and Torilis subgroups, respectively, of recent molecular systematic investigations).