Conifer phylogeny: a comprehensive supermatrix

CATALANO, SANTIAGO; ESCAPA, IGNACIO

Sao Jose do Rio Prieto

Congreso; XXX Meeting of the Willi Hennig Society; 2011

We present a phylogenetic analysis of extant conifers using a supermatrix approach. The dataset included 25 genes of the three genomes. The taxon sampling was very complete, including c.a. 90 % of all extant conifer species and all extant genus. In order to analyze the relationships of conifers as a group, a large number of outgroups were also included (i.e., 105 sp. of Cydadophyta, 67 sp. of Gnetophyta, 15 Magnoliophyta -mainly from basal lineages-, Ginkgo biloba, and representatives of Equistelaes, Psilotales and Filicales). The supermatrix was built downloading most of the available sequences of conifers present in Genbank. Sequences were parsed with scripts described in Goloboff et al. (2008) and aligned with Mafft (Katoh, 2008). Tree searches were conducted in TNT using new technologies. The results show conifers as monophyletic, and sister to a clade conformed by Ginkgo biloba and the cycas lineage. Internal relationships of conifers, obtained using this supermatrix approach, are highly compatible with previous less inclusive hypotheses and show three main clades. The basal lineage includes Pinaceae species, which is the most diverse family among conifers. Second clade comprises Podocarpaceae and Araucariaceae, which were recovered as sister monophyletic groups. The third clade includes the monotypic genus Sciadopitys on the base and then split into two lineages. One of them is represented by Taxaceae and Cephalotaxeae as sister monophyletic groups, and the remaining is represented by the species included in Cupressaceae sensu lato. Moreover, the highly congruent results are also corroborated by generic monophyly and relationships within each family. This study represents the most inclusive phylogenetic study for conifers and supports a high range of hypotheses previously delineated, while rejecting others.