Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.

No abstract

the genus Tulasnella often forms mycorrhizas with orchids and has worldwide distribution. Species of this genus are associated with a wide range of orchids, including endangered hosts. initially, species identification relied mostly on morphological features and few cultures were preserved for later phylogenetic comparisons. In this study, a total of 50 Tulasnella isolates were collected from their natural sites in Minas Gerais, Brazil, cultured, and subjected to a phylogenetic analysis based on alignments of sequences of the internal transcribed spacer (itS) of the nuclear ribosomal DnA. our results, based on phylogeny, integrated with nucleotide divergence and morphology, revealed the diversity of isolated Tulasnella species, which included four new species, namely, Tulasnella brigadeiroensis, Tulasnella hadrolaeliae, Tulasnella orchidis and Tulasnella zygopetali. the conservation of these species is important due to their association with endangered orchid hosts and endemic features in the Brazilian Atlantic forest.

A new endophytic species of Colletotrichum was isolated from an endangered orchid species, Cattleya jongheana in the Parque Estadual da Serra Negra, from the state of Minas Gerais, Brazil. It is described and illustrated as Colletotrichum serranegrense sp. nov. in this study. Morphology and multi-locus phylogenetic analyses based on combined ITS, ACT, TUB2 and CHS-1 sequence data revealed that these isolates were in the Colletotrichum gigasporum species complex and confirmed differences in this compared to other species in this genus.

No abstract

Five new species, two new varieties and three newly reported taxa belonging to the Meliolaceae were collected in fragments of Atlantic forest from Minas Gerais, Brazil, in association with native plants and are described and illustrated herein. The newly described species are Appendiculella eupatorii, Meliola cassiae-ferrugineae, M. mutisiae, M. peruiferae, M. vernaliae. The new varieties are M. garugae var. protii and M. paullinifolii var. rubiginosae. These taxa are reported in Brazil for the first time: Asteridiella cyclopoda, A. entebbeensis var. codiaei and Meliola pazschkeana var. macropoda. We studied other species belonging in Meliolaceae collected on hosts belonging to the Asteraceae, Burseraceae, Euphorbiaceae, Fabaceae (Caesalpinioideae and Papilionoideae) and Sapindaceae in Brazil.

Species from Ceratobasidium are known as orchid mycorrhizal, plant pathogens or saprophytic. In mycorrhizal association with orchids, Ceratobasidium can establish a highly specific interaction. Gomesa recurva is an epiphytic orchid occurring in the Brazilian Atlantic Forest. In the present study mycorrhizal fungi were isolated from roots of G. recurva and its phylogenetic positions was investigated. A total of nine isolates were obtained directly from pelotons and submitted to phylogenetic analysis based on alignments of sequences of the internal transcribed spacer (ITS) of the nuclear ribosomal DNA. Phylogenetic analyzes, along with morphological data, revealed that isolates are distinct from all known Ceratobasidium species and a new species, namely Ceratobasidium gomesae sp. nov., is proposed. Given the dependence on mycorrhizae for germination and protocorm development, knowledge about orchid symbionts is an important factor in managing the conservation of these plants, and future studies may investigate the ability of C. gomesae to promote seed germination.

A new endophytic fungal species, Neopestalotiopsis hadrolaeliae, is described from roots of Hadrolaelia jongheana, an endangered orchid species growing in Brazil. Multigene phylogenetic analyses coupled with morphological observations facilitated the identification of new species isolated from the roots of Hadrolaelia jongheana. Phylogenetic analyses based on ITS, TUB and TEF DNA sequences showed that the new taxon is different from reported Neopestalotiopsis species. Descriptions and illustrations and notes are provided for the new species, which we name herein as Neopestalotiopsis hadrolaeliae.