Andrea I Romero

Fluorescence microscopy: An aid to the elucidation of ascomycete structures

Freshly collected specimens and preserved herbarium material of ascomycetes from a variety of orders were dissected to obtain slide preparations of ascogenous cells, paraphyses, asci and ascospores. Phase contrast, differential interference contrast and fluorescent light microscopy were used to examine each species in a range of mountants including water, erythrosin, Melzers reagent, lactophenol and calcofluor. Detailed results are provided for Diatrype disciformis, Hypoxylon fuscum, Peltigera horizontalis and Pleurostoma ootheca . Asci of Diatrype disciformis were found to have more than one functional wall layer, and its ascogenous cells are described and illustrated for the first time. Hitherto unknown fluorescent rings are described in asci and ascospores of Hypoxylon fuscum . In Peltigera horizontalis fluorescent light microscopy confirms an earlier TEM study of ascus structure and dehiscence in the genus, and asci of Pleurostoma ootheca are described as having lateral thickening, a strongly fluorescing base and a mode of secession from their ascogenous cells apparently previously unknown in the ascomycetes. Most of these features could not be seen at all, or only with difficulty without fluorescent light. Each appeared similar in fresh collections and herbarium specimens dried and preserved for up to one hundred years. Fluorescent light microscopy can provide new information of great value to students of the ascomycetes.

Taxonomic and nomenclatural aspects of Hypoxylon taxa from southern South America proposed by Spegazzini

The holotypes and isotypes of 20 Hypoxylon taxa described by Spegazzini have been examined and their taxonomic positions and nomenclatural problems are discussed. Two new combinations, Annulohypoxylon apiahynum comb. nov. and A. subeffusum comb. nov., are proposed. H. goliath is considered a synonym of Rosellinia bunodes. H. albostigmatosum and H. guarapiense are synonyms of H. anthochroum, H. anthracoderma of H. monticulosum, H. mbaiense of H. notatum, H. paulistanum of H. diatrypeoides, H. plumbeum and H. rubiginosum var. microcarpum of H. perforatum. H. porteri and H. intermedium belong in Biscogniauxia capnodes, H. puiggarii in Annulophypoxylon subeffusum, H. subvinosum. in H. lenormandii, H. turbinatum var. guaraniticum in Phylacia turbinata and H. valsarioides in Creosphaeria sassafras. H. leptascum is transferred to A. leptascum, H. circostomum to Nemania circostoma and H. latissimum to N. latissima. The holotype of H. albostigmatosum has been recovered, thus the lectotypification by Shear no longer is needed. H. subnigricans and H. umbilicatum are confirmed as good taxa. H. anthochroum and H. lenormandii are reported as first records from Argentina (Tucumán).

A new species of Coniochaeta with a key to the species known in Argentina

Coniochaeta rhopalochaeta sp. nov. was isolated from decorticated wood of Bulnesia retama in Argentina. It is distinguished principally by the ascomata with mace-like capitate setae. C. scatigena is first recorded for Argentina. A key to the seven known Argentine species of Coniochaeta is provided. Asci of these species were studied with fluorescence microscopy size of the fluorescent apical ring could be a useful taxonomic character.

Studies on biotrophic fungi from Argentina: Microcyclus porlieriae, with a key to South American species of Microcyclus

The type and a recent collection of Dothidea porlieriae from Argentina are examined, and the species name is transferred to Microcyclus as M. porlieriae . The species is described, illustrated and contrasted with other species of the genus. A key to South American species of Microcyclus is given.

Tripospora militaris sp. nov. from Argentina, with a key to the known species

Four field trips in a Podocarpus parlatorei forest in north-west Argentina yielded 240 collections of Coryneliales. Sixty-eight were of a new species, Tripospora militaris sp. nov., and the remainder belonged to Corynelia oreophila. A key to the four known Tripospora species is given.

Vibrisseaceous fungi from the southern hemisphere, including Chlorovibrissea chilensis (Helotiales, incertaesedis) sp. nov.

The discovery of Chlorovibrissea chilensis sp. nov.expands the distribution of Chlorovibrissea from Australasia to include South America. C. chilensis, phylogenetically distinct from other species in the genus, is also characterized morphologically by its ascoma with emerald green stalk and pale orange-brown head, budding paraphyses and 5–6-septate ascospores. Based on the phylogenetic analysis, the Australasian species Vibrisseaalbofusca is recombined in Chlorovibrissea, despite the fact it lacks the distinctive green pigmentation of other species in this genus. In addition, the genus Vibrissea in a strict phylogenetic sense is confirmed from the southern hemisphere for the first time; Vibrissea truncorum is reported from Chile and V. flavovirens from New Zealand.

New lichen-associated bulbil-forming species of Cantharellales (Basidiomycetes)

Two new genera and four new species of bulbil-forming basidiomycetes are described. Phylogenetic analyses of nuLSU and ITS sequences place them in Cantharellales . A facultative lichenicolous species with yellow to orange-yellow bulbils from South America groups with the type of Burgella and is consequently described as B. lutea . The new species and genus Burgellopsis nivea is introduced for material from Scotland with white bulbils overgrowing saxicolous lichens. An obligate lichenicolous species with particularly large, applanate bulbils developing over Peltigerales in South America could not be placed accurately using ITS sequences and is described as the new species and genus Bulbilla applanata . A European species with brown, facultatively lichenicolous bulbils grouped with Ceratobasidium and Thanatephorus species and is described as the new Ceratobasidium bulbillifaciens .

A new species and new records of Cercophora from Argentina

Three species of Cercophora were found during a survey of the biodiversity of microfungi in northwest Argentina. Cercophora argentina possesses a unique combination of morphological characters and is described as a new species, while C. costaricensis and C. solaris are reported as new records for Argentina. Other species of Cercophora known from this region include C. natalita and C. coprogena, which is fully illustrated for the first time and determined herein to be a synonym of C. californica. All other species are described and illustrated.

Nuevos contaminantes fúngicos de productos alimenticios en Argentina

Resumen Se aislaron e identificaron cinco especies fungicas: Ascotricha chartarum, Leptosphaerulina argentinensis, Veronaea coprophila, Scolecobasidium constrictum y Coremiella cubispora. La primera de ellas fue aislada de envases de papel madera que contenian azucar y las restantes de pure de tomate en conserva. A excepcion de L. argentinensis, las otras cuatro especies restantes son primeros registros y todas han sido aisladas por primera vez en nuestro pais.