Liabeae

Abstract: An extensive sequence comparison of the chloroplast ndhF gene from all major clades of the largest flowering plant family (Asteraceae) shows that this gene provides approximately 3 times more phylogenetic information than rbcL. This is because it is substantially longer and evolves twice as fast. The 5' region (1380 bp) of ndhF is very different from the 3' region (855 bp) and is similar to rbcL in both the rate and the pattern of sequence change. The 3' region is more A+T-rich, has higher levels of nonsynonymous base substitution, and shows greater transversion bias at all codon positions. These differences probably reflect different functional constraints on the 5' and 3' regions of ndhF. The two patterns of base substitutions of ndhF are particularly advantageous for phylogenetic reconstruction because the conserved and variable segments can be used for older and recent groups, respectively. Phylogenetic analyses of 94 ndhF sequences provided much better resolution of relationships than previous molecular and morphological phylogenies of the Asteraceae. The ndhF tree identified five major clades: (i) the Calyceraceae is the sister family of Asteraceae; (ii) the Barnadesioideae is monophyletic and is the sister group to the rest of the family; (iii) the Cichorioideae and its two basal tribes Mutisieae and Cardueae are paraphyletic; (iv) four tribes of Cichorioideae (Lactuceae, Arctoteae, Liabeae, and Vernonieae) form a monophyletic group, and these are the sister clade of the Asteroideae; and (v) the Asteroideae is monophyletic and includes three major clades.

Abstract: Phylogenetic relationships among species representing 57 genera from 15 currently recognized tribes of Asteraceae were assessed by chloroplast DNA restriction site mapping. Phy- logenetic analyses of 328 informative restriction site mutations were performed using both Dollo and Wagner parsimony and the bootstrap method. The results provide strong support for the monophyly of the subfam. Asteroideae, which includes the nine tribes Astereae, Anthemideae, Inuleae, Senecioneae, Calenduleae, Eupatorieae, Heliantheae, Coreopsideae, and Tageteae. The monophyly of the Lactucoideae (excluding the Barnadesiinae) is less strongly supported and this subfamily consists of the six tribes Mutisieae, Cardueae, Vernonieae, Liabeae, Lactuceae, and Arc- toteae. The molecular phylogeny indicates that 13 of 15 tribes are monophyletic, with the Helian- theae and Tageteae being paraphyletic. Several groups of tribes are shown to be closely related, including the Liabeae and Vernonieae, and the Tageteae, Coreopsideae, Heliantheae, and Eupato- rieae, but relationships among the other tribes remain unclear. Tribal placement of five morpho- logically anomalous genera (Blennosperma, Cotula, Echinops, Stokesia, and Ursinia) is also clarified. The chloroplast DNA phylogeny shows almost complete congruence with the less explicit phyletic scheme proposed by Thorne but differs markedly from the cladistically-based phylogeny of Bremer. The availability of a molecular phylogeny for the Asteraceae allows for an independent assessment of the patterns of morphological, chemical, and chromosomal evolution in the family. A much higher incidence of parallelism occurs in secondary chemistry than in morphological characters. The subfam. Asteroideae has a number of evolutionarily derived floral features and it exhibits a much more diverse and biosynthetically complex secondary chemistry.

Abstract: We present a cladistic analysis of 53 taxa from Asteraceae using 72 characters of mainly morphological data. Results reveal subfamily Cichorioideae is paraphyletic. The Mutisieae constitute a basal grade that contains monophyletic groups with Mutisia and Cardueae sensu lato. The Arctotideae, Liabeae, Vernonieae, and Lactuceae form a clade together with subfamily Asteroideae. Our results show some inconsistencies with those from cladistic analyses of molecular data