RESUMO
Elaphomyces compleximurus sp. nov. and E. digitatus sp. nov. are described from the Pakaraima Mountains of Guyana. Macromorphological, micromorphological, habitat and DNA sequence data are provided for each new species. This is the first report of Elaphomyces ascomata associated with ectomycorrhizal members of the Fabaceae and also for the genus from the lowland South American tropics.
Assuntos
Eurotiales/classificação , Micorrizas/classificação , DNA Fúngico/genética , DNA Ribossômico/genética , Ecossistema , Eurotiales/genética , Eurotiales/ultraestrutura , Guiana , Micorrizas/genética , Micorrizas/ultraestrutura , Análise de Sequência de DNA/métodos , Clima TropicalRESUMO
A phylogenetic analysis of Lactarius sect. Deliciosi was performed based on collections of all known species. Several samples of each species were included, originating from a wide geographic range. The two DNA regions we used (ITS and a part of the gene encoding glyceraldehyde-3-phosphate dehydrogenase) showed an incongruent phylogenetic signal. Much attention was paid to carefully observed macro- and micromorphological characters to draw taxonomic conclusions. We currently accept 38 taxa (31 species and seven varieties) in Lactarius sect. Deliciosi worldwide; four species are new to science. More sampling is needed to resolve the status of the North American varieties. Our knowledge of the Asian species in this section remains fragmentary. The monophyly of the section and its position within Lactarius subgenus Piperites, as proposed in recent morphology-based classification schemes, is confirmed. The intrasectional relationships however do not coincide with the color of the latex (as previously supposed). Intercontinental conspecificity is low in general. The name L. deliciosus is wrongfully applied in North and Central America and only two species seem to occur in both Asia and Europe.
Assuntos
Basidiomycota/classificação , Basidiomycota/isolamento & purificação , DNA Espaçador Ribossômico/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Filogenia , Ásia , Basidiomycota/genética , América Central , DNA Fúngico/química , DNA Fúngico/genética , Europa (Continente) , Dados de Sequência Molecular , América do Norte , Análise de Sequência de DNA , Homologia de SequênciaRESUMO
Cantharellus pleurotoides sp. nov. (Cantharellaceae, Cantharellales, Basidiomycota) is described from the Pakaraima Mountains of Guyana, occurring in rainforests dominated by ectomycorrhizal Dicymbe spp. (Caesalpiniaceae). This fungus is singular among Cantharellus species described worldwide in possessing a pleurotoid basidioma. Macromorphological, micromorphological, and habitat data are provided for the new species.
Assuntos
Basidiomycota/isolamento & purificação , Árvores/microbiologia , Basidiomycota/classificação , Basidiomycota/ultraestrutura , Ecossistema , Guiana , Microscopia de Contraste de Fase , Clima TropicalRESUMO
Pseudotulostoma volvata (O. K. Mill. and T. W. Henkel) is a morphologically unusual member of the otherwise hypogeous Elaphomycetaceae due to its epigeous habit and exposed gleba borne on an elevated stalk at maturity. Field observations in Guyana indicated that P. volvata was restricted to rain forests dominated by ectomycorrhizal (EM) Dicymbe corymbosa (Caesalpiniaceae), suggesting an EM nutritional mode for the fungus. In this paper, we confirm the EM status of P. volvata with a combination of morphological, molecular, and mycosociological data. The EM status for P. volvata corroborates its placement in the ectotrophic Elaphomycetaceae.
Assuntos
Ecossistema , Eurotiales/classificação , Micorrizas/classificação , Eurotiales/citologia , Eurotiales/genética , Fabaceae/microbiologia , Guiana , RNA Fúngico/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie , Clima TropicalRESUMO
Morphological and habitat descriptions, illustrations and taxonomic discussions are presented for two newly described species of pleurotoid Lactarius, L. brunellus and L. multiceps, from the Pakaraima Mountains of Guyana. A third species, L. igapoensis, is synonymized with L. panuoides.