Multi-locus phylogenetic reconstructions reveal ample reticulate relationships among genera in Anthemideae subtribe Handeliinae (Compositae)

In order to clarify the phylogenetic relationships among the genera of Compositae-Anthemideae subtribe Handeliinae, we analysed sequence variation on both the plastidic (cpDNA trnL-rpl32 intergenic spacer region) and the nuclear genome (nrDNA ITS + 5.8S + ETS and three single-copy markers) for representatives of all genera assigned to this subtribe in preceding morphology- and molecular-based analyses. Incongruence among the individual gene trees reconstructed is interpreted as being due to extensive hybridisation between the evolutionary lineages because a coalescent-based species-tree reconstruction, that takes gene-tree incongruence due to incomplete lineage sorting into account, leads to a very limited number of monophyletic groups with statistically significant support values. Nevertheless, our present analyses demonstrate (a) the close relationship of subtribes Handeliinae and Artemisiinae, (b) the lack of phylogenetic independence of subtribes Handeliinae and Cancriniinae, (c) the inclusion of the genus Microcephala in the Handeliinae (as sister to Cancrinia), (d) the close relationship of Lepidolopsis and Tanacetopsis, and (e) the subdivision of Allardia into two lineages, with A. subg. Allardia being related to Trichanthemis and Ugamia (all of them with hairy achenes) and A. subg. Waldheimia to the genus Richteria (glabrous pericarp).