Phylogenetic analyses of diverse Podaxis specimens from Southern Africa reveal hidden diversity and new insights into associations with termites

TY - JOUR

T1 - Phylogenetic analyses of diverse Podaxis specimens from Southern Africa reveal hidden diversity and new insights into associations with termites

AU - Conlon, Benjamin H.

AU - de Beer, Z. Wilhelm

AU - de Fine Licht, Henrik Hjarvard

AU - Aanen, Duur K.

AU - Thomas-Poulsen, Michael

PY - 2016/9

Y1 - 2016/9

N2 - 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.

AB - 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.

U2 - 10.1016/j.funbio.2016.05.011

DO - 10.1016/j.funbio.2016.05.011

M3 - Journal article

C2 - 27567713

SN - 1878-6146

VL - 120

SP - 1065

EP - 1076

JO - Fungal Biology

JF - Fungal Biology

IS - 9

ER -