Principal features of the cpDNA evolution in Taraxacum (Asteraceae, Lactuceae):: a conflict with taxonomy

Phylogenetic relationships based on the chloroplast genome of Taraxacum were studied. Representative samples of 44 sections or species groups and a number of isolated species were analyzed. On the basis of the sequence variation in psbA-trnH and in trnL-trnF, mutations associated with RFLPs were monitored. Five RFLPs without homoplasy were recognized and used to reconstruct four main cpDNA groups (haplotypes); Group I is ancestral and, contrary to the information in the primary sequences, the RFLPs were not distinct from those of the outgroup species of Agoseris and Prenanthes. This group corresponds to dandelions believed to be ancestral on the basis of morphological data and previous studies of the chloro last genome. A comparison of parsimony analysis of morphological and chloroplast data showed an overall lack of congruence. The conflict can most probably be accounted for as a consequence of reticulation.