title: Phylogenetic relationships in Asarum: Effect of data partitioning and a revised classification.
abstract: OBJECTIVE
  Generic boundaries and infrageneric relationships among the charismatic temperate magnoliid Asarum sensu lato (Aristolochiaceae) have long been uncertain. Previous molecular phylogenetic analyses used either plastid or nuclear loci alone and varied greatly in their taxonomic implications for the genus. We analyzed additional molecular markers from the nuclear and plastid genomes, reevaluated the possibility of a derived loss of autonomous self-pollination, and investigated the topological effects of matrix-partitioning-scheme choice.
  
  
  METHODS
  We sequenced seven plastid regions and the nuclear ITS1-ITS2 region of 58 individuals representing all previously recognized Asarum s.l. segregate genera and the monotypic genus Saruma. Matrices were partitioned using common a priori partitioning schemes and PartitionFinder.
  
  
  RESULTS
  Topologies that were recovered using a priori partitioning of matrices differed from those recovered using a PartitionFinder-selected scheme, and by analysis method. We recovered six monophyletic groups that we circumscribed into three subgenera and six sections. Putative fungal mimic characters served as synapomorphies only for subgenus Heterotropa. Subgenus Geotaenium, a new subgenus, was recovered as sister to the remainder of Asarum by ML analyses of highly partitioned datasets. Section Longistylis, also newly named, is sister to section Hexastylis.
  
  
  CONCLUSIONS
  Our analyses do not unambiguously support a single origin for all fungal-mimicry characters. Topologies recovered through the analysis of PartitionFinder-optimized matrices can differ drastically from those inferred from a priori partitioned matrices, and by analytical method. We recommend that investigators evaluate the topological effects of matrix partitioning using multiple methods of phylogenetic reconstruction.
authors.affiliation: The Ohio State University Museum of Biological Diversity, Department of Evolution, Ecology, and Organismal Biology, 1315 Kinnear Road, Columbus, Ohio 43212 USA.
authors.forename: Brandon T
authors.initials: BT
authors.lastname: Sinn
authors.affiliation: The New York Botanical Garden, 2900 Southern Boulevard, Bronx, New York 10458-5126 USA.
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Kelly
authors.affiliation: The Ohio State University Museum of Biological Diversity, Department of Evolution, Ecology, and Organismal Biology, 1315 Kinnear Road, Columbus, Ohio 43212 USA.
authors.forename: John V
authors.initials: JV
authors.lastname: Freudenstein
mesh_terms: D030023:Asarum / Q000145:classification* / Q000235:genetics*; D002467:Cell Nucleus / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D018087:Plastids / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant
keywords: Asarum; Asiasarum; Bayesian inference; Geotaenium; Heterotropa; Hexastylis; Japonasarum; PartitionFinder; maximum likelihood; maximum parsimony