title: Phylogenetic analyses of Podaxis specimens from Southern Africa reveal hidden diversity and new insights into associations with termites.
abstract: Although frequently found on mounds of the grass-cutting termite genus Trinervitermes, virtually nothing is known about the natural history of the fungal genus Podaxis (Agaricaceae) nor why it associates with termite mounds. More than 40 species of this secotioid genus have been described since Linnaeus characterised the first species in 1771. However, taxonomic confusion arose when most of these species were reduced to synonymy with Podaxis pistillaris in 1933. Although a few more species have since been described, the vast majority of specimens worldwide are still treated as P. pistillaris. Using 45 fresh and herbarium specimens from Southern Africa, four from North America and one each from Ethiopia, and Kenya, we constructed the first comprehensive phylogeny of the genus. Four of the genotyped specimens were more than 100 y old. With the exception of the type specimen of Podaxis rugospora, all herbarium specimens were labelled as P. pistillaris or Podaxis sp. However, our data shows that the genus contains at least five well-supported clades with significant inter-clade differences in spore length, width and wall thickness, and fruiting body length, supporting that clades likely represent distinct Podaxis species. Certain clades consistently associate with termites while others appear entirely free-living.
authors: Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Denmark; Molecular Ecology, Institute of Biology/Zoology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 4, 06099 Halle an der Saale, Germany. Electronic address: benjamin.conlon@zoologie.uni-halle.de.
authors: Benjamin H
authors: BH
authors: Conlon
authors: Department of Microbiology, Forestry and Agriculture Biotechnology Institute, University of Pretoria, Pretoria, Gauteng 0001, South Africa. Electronic address: wilhelm.debeer@fabi.up.ac.za.
authors: Z Wilhelm
authors: ZW
authors: de Beer
authors: Section for Organismal Biology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark. Electronic address: hhdefinelicht@plen.ku.dk.
authors: Henrik H
authors: HH
authors: De Fine Licht
authors: Laboratory of Genetics, Plant Sciences Group, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, Netherlands. Electronic address: duur.aanen@wur.nl.
authors: Duur K
authors: DK
authors: Aanen
authors: Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Denmark. Electronic address: MPoulsen@bio.ku.dk.
authors: Michael
authors: M
authors: Poulsen
mesh_terms: D000349:Africa; D000353:Africa, Southern; D000363:Agaricales / Q000145:classification* / Q000166:cytology / Q000235:genetics* / Q000302:isolation & purification; D000818:Animals; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D014644:Genetic Variation; D020049:Isoptera / Q000382:microbiology*; D009656:North America; D010802:Phylogeny; D012331:RNA, Fungal / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000166:cytology
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012331:RNA, Fungal; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S
keywords: Herbarium; Namibia; Nasutitermitinae; South Africa; Trinervitermes