Phylogenetic relationships, saturation and marker-use in the Long Branch Clade of Annonaceae

The high level of morphological homoplasy in Annonaceae necessitates the use molecular methods in order to resolve the higher-level relationships in the family. Clarity of phylogenetic relationships is important because a wealth of morphological data are available but the lack of a phylogenetic framework has prohibited evolutionary interpretation of this data. In this study the relationships among the genera of the Long Branch Clade of Annonaceae are elucidated. The only remaining uncertainty revolves around the placement of Guatteria and a clade containing the Duguetia group and Xylopia and Artabotrys. Long branch attraction could be causing this result. Furthermore, the plastid rbcL, matK, ndhF, atpB-rbcL, trnS-G, trnT-L, trnT-F and psbA-trnH regions were investigated with respect to saturation and usefulness in phylogenetic reconstruction. ndhF and trnL-F prove to provide sufficient data to produce a completely resolved and overall strongly supported topology. matK carries little phylogenetic signal and rbcL slightly more, for recovering phylogenetic relationships in Annonaceae but both to a far lesser extent than ndhF. The non-coding regions atpB-rbcL, trnS-G and psbA-trnH (the only region showing signs of saturation) seem t