Neotropical Studies on Hymenochaetaceae: Unveiling the Diversity and Endemicity of Phellinotus.

Phellinotus, a neotropical genus of wood-decay fungi commonly found on living members of the Fabaceae family, was initially described as containing two species, P. neoaridus and P. piptadeniae. The members of this genus, along with six other well-established genera and some unresolved lineages, are the current representatives of the 'phellinotus clade'. On the other hand, based on a two-loci phylogenetic analysis, some entities/lineages of the 'phellinotus clade' have been found in Fomitiporella s.l. In this work, we performed four-loci phylogenetic analyses and based on our results the genera of the 'phellinotus clade' are shown to be monophyletic groups. In addition to the natural groups confirmed as different genera, morphological revisions, phylogenetic relationships, and host distribution of different specimens resembling P. neoaridus and P. piptadeniae revealed three new species in the Phellinotus genus, referred to here as P. magnoporatus, P. teixeirae and P. xerophyticus. Furthermore, for P. piptadeniae a narrower species concept was adopted with redefined morphological characters and a more limited distribution range. Both P. neoaridus and P. teixeirae have a distribution range restricted to seasonally dry tropical forests in South America. Additionally, based on detailed morphological revisions Phellinus badius, Phellinus resinaceus, and Phellinus scaber are transferred to the Phellinotus genus. The geographic distribution and host range of the genus are then discussed.

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.

Fusarium equiseti LPSC 1166 and its in vitro role in the decay of Heterostachys ritteriana leaf litter.

The role of microorganisms in litter degradation in arid and semi-arid zones, where soil and water salinization is one of the main factors limiting carbon turnover and decay, remains obscure. Heterostachys ritteriana (Amaranthaceae), a halophyte shrub growing in arid environments such as "Salinas Grandes" (Córdoba, Argentina), appears to be the main source of organic matter in the area. Little is known regarding the microorganisms associated with H. ritteriana, although they are a potential source of enzymes such as cellulolytic ones, which might be important in biotechnological fields such as bioethanol production using ionic liquids. In the present study, by studying the microbiota growing on H. ritteriana leaf litter in "Salinas Grandes," we isolated the cellulolytic fungus Fusarium equiseti LPSC 1166, which grew and degraded leaf litter under salt stress. The growth of this fungus was a function of the C substrate and the presence of NaCl. Although in vitro the fungus used both soluble and polymeric compounds from H. ritteriana litter and synthesized extracellular ß-1,4 endoglucanases, its activity was reduced by 10% NaCl. Based on these results, F. equiseti LPSC 1166 can be described as a halotolerant cellulolytic fungus most probably playing a key role in the decay of H. ritteriana leaf litter in "Salinas Grandes."