Data from: High diversity and widespread occurrence of mitotic spore mats in ectomycorrhizal Pezizales

Fungal mitospores may function as dispersal units and/ or spermatia and thus play a role in distribution and/or mating of species that produce them. Mitospore production in ectomycorrhizal (EcM) Pezizales is rarely reported, but here we document mitospore production by a high diversity of EcM Pezizales on three continents, in both hemispheres. We sequenced the internal transcribed spacer (ITS) and partial large subunit (LSU) nuclear rDNA from 292 spore mats (visible mitospore clumps) collected in Argentina, Chile, China, Mexico and the USA between 2009 and 2012. We collated spore mat ITS sequences with 105 fruit body and 47 EcM root sequences to generate operational taxonomic units (OTUs). Phylogenetic inferences were made through analyses of both molecular data sets. A total of 48 OTUs from spore mats represented six independent EcM Pezizales lineages and included truffles and cup fungi. Three clades of seven OTUs have no known meiospore stage. Mitospores failed to germinate on sterile media, or form ectomycorrhizas on Quercus, Pinus and Populus seedlings, consistent with a hypothesized role of spermatia. The broad geographic range, high frequency and phylogenetic diversity of spore mats produced by EcM Pezizales suggests that a mitospore stage is important for many species in this group in terms of mating, reproduction and/or dispersal

Ectomycorrhizal contaminants on experimental roots

These ectomycorrhizal roots were selected and sequenced by ME Smith, RA Healy and GM Bonito in May of 2011. They come from sequenced root tips from axenically grown seedlings that were inoculated with mitospores, and then transferred to a growth chamber including other inoculated plants. None of the mitospore phylotypes were recovered from root tips, but three contaminant ectomycorrhizal species were sequenced from the roots. We think they came from water splash during watering of adjacent pots that had been purposely inoculated with Tuber borchii. Identifications were from ITS sequence similarity at 97%

Hydnobolites_ITS_alignment

This is an alignment of ITS sequences (ITS1, 5.8s, ITS2) from fruit bodies, ectomycorrhizal roots and mitotic spore mats