Plant systematics and evolution vol:225 issue:1-4 pages:185-199
A first report on the problematic phylogenetic position of Heptacodium (2 spp.; China) using molecular data from chloroplast DNA is presented. Amplification of ORF2280 homolog region was executed in a number of representative taxa in order to determine if Heptacodium shows similar structural rearrangements as other Dipsacales. DNA sequences of ndhF were generated to clarify the phylogenetic position of Heptacodium among Caprifoliaceae (s.l.). Six outgroup taxa and fifteen representatives of Dipsacales were sampled and more than 2100 basepairs of ndhF sequence were used in a cladistic analysis. Parsimony analysis produced two shortest trees and showed Heptacodium as sister to all members of Caprifoliaceae (s.str.), although weakly supported. Additionally, trees were constructed with ndhF data supplemented with available rbcL sequences and a morphological data set. Results of all analyses support an unresolved basal position for Heptacodium among Caprifoliaceae (s.l.), which in part explains the difficulty experienced previously in classifying the genus.