Publications by authors named "Patrick Brandon Matheny"

Secondary metabolites are a heterogeneous class of chemicals that often mediate interactions between species. The tryptophan-derived secondary metabolite, psilocin, is a serotonin receptor agonist that induces altered states of consciousness. A phylogenetically disjunct group of mushroom-forming fungi in the Agaricales produce the psilocin prodrug, psilocybin.

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A new genus and three new species of Agaricales are described from the Pakaraima Mountains of Guyana in the central Guiana Shield. All three of these new species fruit on the ground in association with species of the ectomycorrhizal (ECM) tree genus Dicymbe (Fabaceae subfam. Caesalpinioideae) and one species has been shown to form ectomycorrhizas.

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Although fungi are one of the most diverse groups of organisms, little is known about the processes that shape their high taxonomic diversity. This study focuses on evolution of ectomycorrhizal (ECM) mushroom-forming fungi, symbiotic associates of many trees and shrubs, in the suborder Tricholomatineae of the Agaricales. We used the BiSSE model and BAMM to test the hypothesis that the ECM habit represents an evolutionary key innovation that allowed the colonization of new niches followed by an increase in diversification rate.

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The absence of an adequate fossil record can hinder understanding the process of diversification that underlies the evolutionary history of a given group. In such cases, investigators have used ultrametric trees derived from molecular data from extant taxa to gain insights into processes of speciation and extinction over time. Inadequate taxon sampling, however, impairs such inferences.

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Phylogenetic analysis of ITS sequences of members of the Craterellus cornucopioides complex (Black Trumpet mushrooms) supports the taxonomic separation of Craterellus fallax apart from C. cornucopioides, with which it has been synonymized in the past. Examination of Pinus virginiana ectomycorrhizal (ECM) root tips and sequence comparison with other insufficiently identified environmental sequences from roots of Tsuga, Quercus, and possibly Castanea supports a broad host range in North America for the ECM symbiont C.

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