Revisão da família Geastraceae corda (Geastrales, Basidiomycota) com ênfase em espécies neotropicais

Abstract

About 97% of existing fungi species have not been described by science, although the identification being the basis for many appliced studies (ex: bioprospecting, evolution, ecology, conservation). Barcodes have been very useful to species delimitation. Mainly for gasteroid fungi (Basidiomycota), the Internal Transcribed Spacer of Nuclear rDNA (ITS) has demonstrated to be very efficacy to discover hidden diversity. The family Geastraceae is constituted by the gasteroid genus Geastrum and Myriostoma, being the specimens popularly known as earthstars. Although it is one of the richest families in the Geastrales order, the knowledge about the diversity of this family has gaps, especially in the Neotropical region, where there are megadiverse countries, “hotspots” and tropical ecosystems, which have high potential to shelter hidden diversity. Thus, this study aimed to review collections of family Geastraceae, emphasizing those with Neotropical distribution. Two hundred and fifteen samples from 10 distinct international and national fungal collections were investigated, of these, 14 type collections. The methodoly consisted in a deep revision of morphological characters, besides the molecular phylogenetic analyses of the DNA regions ITS, LSU, ATP6, RPB2 e TEF1α, following Maximum Parsimony, Maximum Likelihood and Bayesian inference criteria. There were generated 186 new sequences, which were compared with 294 homologue sequences from GenBank data. Twelve news species of Geastrum were described: G. laevisporum J.O. Sousa & Baseia; G. pusillipilosum J.O. Sousa et al.; G. verrucoramulosum T.S. Cabral, J.O. Sousa & Baseia; G. magnosporum J.O. Sousa et al.; G. caatingense J.O. Sousa, M.P. Martín & Baseia; G. parvistellum J.O. Sousa, M.P. Martín & Baseia; G. baculicrystallum J.O. Sousa et al.; G. brunneocapillatum J.O. Sousa et al.; G. courtecuissei P.-A. Moreau & C. Lécuru, G. neoamericanum J.O. Sousa et al.; G. rubellum P.-A. Moreau & C. Lécuru; G. rubropusillum J.O. Sousa et al. For the genus Myriostoma, two new species were described: M. calongei Baseia, J.O. Sousa, & M.P. Martín and M. australianum J.O. Sousa Baseia & M.P. Martín; moreover, two new combinations were proposed: M. areolatum (Calonge & M. Mata) M.P. Martín, J.O. Sousa & Baseia and M. capillisporum (V.J. Stanek) L.M. Suz et al. A lectotype and an epitype for the specie M. coliforme (Dicks.) Corda was elected. The data generated by this revision changed the systematic interpretations about the family Geastraceae, it was possible to prove that there were species complex which underestimated the knowledge about the richness of this family in Neotropical region.