Macrofungal diversity in Colombian Amazon forests varies with regions and regimes of disturbance

Here we present the results of fungal biodiversity studies from some selected Colombian Amazon forests in relationship to plant biodiversity and successional stages after slash and burn agriculture. Macrofungal diversity was found to differ between forests occurring in two regions (Araracuara vs Amacayacu) as well as between flooded forests and terra firme forests in the Amacayacu region. Macrofungal biodiversity differed between regeneration states of different age in the Araracuara region. Suitable substrates, especially dead wood that occurred as a result of recent slash and burn agriculture, resulted in the formation of many sporocarps of wood-inhabiting species. Putative ectomycorrhizal species were found in a dipterocarp forest. Fifty two percent of the macrofungal species could not be identified to the species level, but could be assigned to a genus, and it is likely that a significant portion of these represent species new to science. Long term studies are needed to obtain a comprehensive and complete understanding of the diversity and functioning of mycobiota in Amazon forest ecosystems

Genetic population structure of the agaric Blastosporella zonata (Lyophyllaceae) reveals cryptic species and different roles for sexual and asexual spores in dispersal

Blastosporella zonata is one of the few basidiomycete fungi that produce asexual spores (conidia) on the mushroom. The role of these conidia in the fungal lifecycle is not known. We tested whether conidia are being utilized in local dispersal by looking for signatures of clonality in 21 samples from three localities separated by about three kilometres in Murillo, Colombia. To identify clonally related individuals, we sequenced three polymorphic markers at two unlinked loci (nuclear rRNA: ITS and LSU, and TEF1α) for all collections plus three herbarium samples. We identified two sets of clonally related individuals growing closely together in one of the three localities, and only one pair shared between localities. In all three localities we observed multiple non-clonally related dikaryons showing that sexual reproduction is also important. Our results indicate that the conidia on the mushroom are primarily important for local dispersal. Unexpectedly, ur results also indicate two reproductively isolated populations, possibly representing cryptic biological specie

Ectomycorrhizal fungi diversity in a white sand forest in western Amazonia

The genera Dicymbe and Aldina (Fabaceae) host ectomycorrhizal fungi (EcM) and are common in white sand forests (WSFs), a highly specialized habitat with a high level of plant endemism compared with terra-firme forests. In this study, we visited four times a 1-ha permanent plot established in a small patch of a WSF in the south of Colombia Amazonia. Forty-eight species of EcM fungi were recovered from sporocarps and 15 ITS species-level were detected from root tips. Seventeen species were new reports to Colombia and seven corresponded to undescribed species. These results confirm that this WSF supports a significant EcM fungal diversity. Most of the species found in this study have been previously reported to be associated with other legume and/or dipterocarp species from geographically distant forests. The long-distance occurrence combined with low host specificity, suggest the possibility of gene flow between geographically distant populations of EcM fungi in neotropical lowland rainforests