Gerardo Robledo

Perenniporiella chaquenia sp nov and further notes on Perenniporiella and its relationships with Perenniporia (Poriales, Basidiomycota)

Perenniporiella chaquenia sp. nov. is described from Argentina. New records of P. pendula and P. micropora are discussed. A key to Perenniporiella species is presented. Preliminary phylogenetic relationships of Perenniporiella are inferred from parsimony and Bayesian analysis of a combined set of DNA sequence data (nuclear ribosomal partial LSU and ITS). It demonstrated that Perenniporiella forms a well resolved monophyletic clade distantly related to Perenniporia s.s. It also clearly showed that within Perenniporia as usually conceived other morphologically homogeneous group of taxa, such as the P. ochroleuca or P. vicina alliances, form well resolved clades, which could be recognized as distinct genera. The differentiation of the hyphal system and the basidiospores morphology are outlined as critical features for the definition of genera in the Perenniporia complex.

Phylloporia nouraguensis, an undescribed species on Myrtaceae from French Guiana

Abstract Phylloporia nouraguensis sp. nov. is described on the basis of several collections made in French Guiana. The species was found growing on living (or occasionally dead), small apical twigs of a species of Myrcia (Myrtaceae), in the so-called “low forest” covering the upper slopes of the Nouragues inselberg.

Fomitiporia neotropica, a new species from South America evidenced by multilocus phylogenetic analyses

During the revision of the Neotropical Fomitiporia species with resupinate basidiomata, several collections from southern Brazil, central Argentina, and French Guiana were found to represent an undescribed species, on the basis of molecular (DNA sequence) and additional morphological and distributional data. This taxon is described and illustrated as Fomitiporia neotropica sp. nov. The species belongs to the Fomitiporia langloisii lineage, the lineage type within Fomitiporia that so far contains only species with resupinate basidiomata spanning exclusively over the Neotropics. Fomitiporia neotropica is morphologically variable regarding the presence/absence of hymenial setae, and secondarily, regarding the pore size. It also inhabits distinct ecosystems characterized by variable moisture regimes. The range of divergent positions in the DNA sequences used in this study (ITS, 28S, partial tef1-α, and rpb2), between specimens from distant origins, are of the same magnitude as those between specimens of other related species, such as F. langloisii, F. dryophila, F. maxonii, or F. mediterranea. A key to the species from the F. langloisii lineage is given.

Species complexes in Hericium (Russulales, Agaricomycota) and a new species - Hericium rajchenbergii - from southern South America

Species of the genus Hericium are generally recognized by macro morphology of their basidiomes, while they are very similar in the microscope. As a result, species boundaries are not always clear, and many collections are subsumed under incorrect names. We report on a thorough phylogenetic analysis based on ITS sequences to clarify the application of the most common names in the genus. H. alpestre, H. americanum, and H. erinaceus cannot readily be distinguished by their ITS sequences alone, while they are kept separate by characters from substrate preferences, geographical distribution, and macro morphology. A neotype is selected for H. alpestre. A well supported clade includes H. coralloides together with other, unnamed taxa. One of these, H. rajchenbergii from Argentina, is here described as new to science.

Diversity of the poroid Hymenochaetaceae (Basidiomycota) from the Atlantic Forest and Pampa in Southern Brazil

Abstract A synopsis of the current knowledge about the poroid Hymenochaetaceae from Southern Brazil (States Paraná, Santa Catarina and Rio Grande do Sul) is presented. Fortytwo species belonging to nine genera are reported from the areas surveyed. An annotated, partly illustrated, checklist and identification keys are provided. The new combinations Fomitiporia bambusarum and Fulvifomes rhytiphloeus are also proposed. Atlantic Forest / Hymenochaetales / Neotropics / Taxonomy

Gyrodontium sacchari (Spreng.: Fr.) Hjortstam (Boletales, Basidiomycota) in America: New records and its geographic distribution

Gyrodontium sacchari (Spreng.: Fr.) Hjortstam is reported from two new areas of northwest and northeast Argentina, Brazil, and French Guiana. A geographic distribution map of the species in America and a discussion on its pattern of distribution are presented.

Characterization of Schinopsis Haenkeana wood Decayed by Phellinus Chaquensis (Basidiomycota, Hymenochaetales)

Schinopsis haenkeana is a native tree to the Chaco Serrano Forests in Argentina. The white-rot fungus Phellinus chaquensis degrades its wood, causing a whiterot type of decay. The objective of this study was to investigate the structural alterations caused by P. chaquensis in S. hankeana decayed naturally and in vitro. Sound living branches with decay and basidiocarps of P. chaquensis were sampled from the field and in vitro decay tests were performed according to the ASTM D-2017-81 standard method. Naturally decayed branches exhibited an innermost discolored zone with white-rot decay and an outer yellowish-white portion of sound sapwood. Using LM and SEM, degraded tissue displayed diagnostic characters of selective delignification and simultaneous decay. Findings indicate that P. chaquensis causes a mottled pattern of decay (selective delignification plus simultaneous decay) in S. haenkeana wood. Other features such as accumulation of extractives, profuse deposition of crystals and tyloses, typical ofSchinopsis spp. heartwood, were additionally observed. In laboratory degraded material, signs of selective delignification and incipient stages of simultaneous decay were noticeable only microscopically. Chemical analysis revealed an oxidative alteration of aromatic moieties in naturally decayed samples which might be related to the accumulation of phenols as a response to fungal attack when compared to sound samples. Naturally degraded sapwood exhibits anatomical and chemical modifications that indicate the development of discolored wood derived from the host-pathogen interaction.

Decrypting the Polyporus dictyopus complex: Recovery of Atroporus Ryvarden and segregation of Neodictyopus gen. nov. (Polyporales, Basidiomyocta)

Polyporus dictyopus, with a large number of heterotypic synonyms, has been traditionally considered a species complex, characterized by wide morphological variation and geographic distribution. Thus, neotropical specimens previously identified as P. dictyopus from Amazonia, Cerrado and Atlantic Forest biomes were studied based on detailed macro- and micromorphological examination and phylogenetic analyses, using distinct ribosomal and protein-coding genomic regions: the nuclear ribosomal internal transcribed spacer (nrITS), nuclear ribosomal large subunit (nrLSU), and RNA polymerase II second subunit (RPB2). Two unrelated generic lineages, each one represented by different species, are reported: Atroporus is recovered and re-circumscribed to include A. diabolicus and A. rufoatratus comb. nov.; Neodictyopus gen. nov. is proposed to accommodate N. dictyopus comb. nov. and two new species, N. atlanticae and N. gugliottae. Our study showed that at least five distinct species were hidden under the name P. dictyopus. Detailed descriptions, pictures, illustrations, and a key are provided for Atroporus and Neodictyopus species.

Phellinus piptadeniae (Hymenochaetales: Hymenochaetaceae): taxonomy and host range of a species with disjunct distribution in South American seasonally dry forests

Phellinus piptadeniae (Hymenochaetaceae, Hymenochaetales) as currently accepted is characterized by having applanate to ungulate basidiome with the pilear surface concentrically sulcate, radially cracked in old specimens, and a sinuous black line in the context. The species has been recorded in seasonally dry forests of different Brazilian domains, often associated with legume hosts. It occurs highly specifically associated with Piptadenia gonoacantha in semideciduous forest of the Atlantic Forest domain in southeastern Brazil. In the Caatinga dry woodlands, northeastern Brazil, Phellinus piptadeniae occurs as host recurrent of different Piptadenia species. During recent polypore surveys, specimens that are morphologically similar to the type were collected in seasonally dry tropical forests (SDTFs) of northwestern Peru also on legume hosts (Libidibia glabrata and Pithecellobium excelsum). In this paper, we discuss the morphological variation, host range, and distribution of Phellinus piptadeniae in the context of the historical biogeography of the neotropical SDTF biome. Some taxonomic implications that should be further investigated in a molecular phylogenetic framework are also addressed.

Influence of light on lignin-degrading activities of fungal genus Polyporus s. str

Six strains belonging to five species of Polyporus (P. arcularius, P. arcularioides, P. tricholoma, P. cfr. tricholoma, and P. varius), collected from an Atlantic Forest area in Misiones (Argentina), where species usually grow exposed to high temperatures and humidity, were identified by morphological and molecular analyses. P. tricholoma (BAFC 4536) and P. arcularioides (BAFC 4534) were selected by their lignin‐degrading enzyme production, their ability to produce primordial of basidiomes under submerged fermentation, and the decrease in lignin content caused in Poplar wood (up to 29% after 45 days). Among several variables evaluated with a Plackett–Burman design (glucose, copper, vanillic acid and manganese concentration, incubation period, and light incidence), the most important factor affecting laccase and Mn‐peroxidase (MnP) production by both strains, was light incidence. Light induced fruit body development but diminished laccase and MnP production. Moreover, a modified isoenzymatic laccase pattern was observed, showing additional isoenzymes when fungi were cultivated under darkness and differences in optimal temperature. Although the studied strains did not produce high laccase and MnP titers (uppermost detected 4230 and 90 U L−1, respectively), their laccases showed thermal stability and optimal temperature above 70 °C, representing an interesting source in the search of thermo‐tolerant enzymes for biotechnological applications.