TRIBAL PHYLOGENY OF THE ASTERACEAE BASED ON 2 NONCODING CHLOROPLAST SEQUENCES, THE TRNL INTRON AND TRNL TRNF INTERGENIC SPACER/

Asteraceae are the largest family of dicotyledonous plants and have lo ng been known for their taxonomic complexity. The ubiquitous paralleli sms in morphology within the family have made phylogenetic reconstruct ion and tribal circumscription an area of long debate. In this study w e explored the utility of using two relatively short non-coding chloro plast DNA sequences, the trnL intron and trnL/trnF intergenic spacer, to resolve phylogenetic relationships among the tribes. The results of the phylogenetic analysis produced trees that are topologically congr uent with prior phylogenetic hypotheses based on both morphological an d molecular data sets. The Asteroideae are a monophyletic group, but t he Cichorioideae are paraphyletic. The primary clades of the Cichorioi deae are the Mutisieae-Cardueae, Liabeae-Vernonieae, and of the Astero ideae, the Inuleae-Plucheeae, Astereae-Anthemideae, Senecioneae-Gnapha lieae, and the helianthoid clade (Helenieae, Heliantheae s. str., and Eupatorieae). The Inuleae-Plucheeae clade is sister to the remainder o f the Asteroideae, and the paraphyly of the Inuleae s.l. (Gnaphalieae, Inuleae s. str., and Plucheeae) is firmly supported by our analysis. Our study illustrates the utility of the trnL intron and trnL/F interg enic spacer for resolving relationships among tribes of the Asteraceae . Using approximately 874 bp, we were able to produce a phylogeny of c omparable resolution to phylogenies based on well-known coding regions such as rbcL and ndhF. For phylogenetic inference at the family level the trnL intron and trnL/F spacer provide similar levels of resolutio n to longer coding sequences (e.g., rbcL, ndhF), while having the adva ntage of being much easier io amplify and sequence due to their short lengths and universal primers. The numerous insertions and deletions c ommonly found in this region are easily aligned and are phylogenetical ly informative, thus adding considerably to the information content pe r base pair sequenced.