Mario Rajchenberg

Obba and Sebipora, new polypore genera related to Cinereomyces and Gelatoporia (Polyporales, Basidiomycota)

Cinereomyces clade is a newly proposed monophyletic group of polypores containing currently four genera and five species, including two promising biopulping fungi, Ceriporiopsis rivulosa and C. subvermispora. The Cinereomyces clade is well-delimited in nrDNA-based phylogenetic analysis, but its position in Polyporales remains unclear. Its closest relative may be found in the core polyporoid clade. Only a few morphological characters are common for all the species in the clade, e.g. CB– and CRB+ hyphae, white fruiting bodies, presence of oil, and middle-sized spores. Culturally, the species are unified by producing simple-septate generative hyhpae in the margin, which produce simple-clamped hyphae backwards. The genus Gelatoporia is the correct place for Ceriporiopsis subvermispora. Two new genera are described in the group: Obba to incorporate C. rivulosa and a new austral species, Obba valdiviana, known from southern Argentina and recorded here also from Tasmania, and Sebipora to accommodate a new species from tropical Asia, S. aquosa. ITS sequences imply that Eurasian Gelatoporia subvermispora may belong to a different species from the North American one. G. subvermispora is recorded as new to Indonesia.

Rhizochaete, a new genus of phanerochaetoid fungi

A new basidiomycete genus, Rhizochaete (Phanerochaetaceae, Polyporales), is described. Rhizochaete is characterized by a smooth to tuberculate, pellicular hymenophore and hyphal cords that turn red or violet in potassium hydroxide, monomitic hyphal system of simple or nodose septate hyphae, cystidia, and small, cylindrical to subglobose basidiospores. It morphologically is most similar to Phanerochaete. Analyses of nuclear ribosomal and internal-transcribed spacer region sequence data support a close relationship between Rhizochaete and Phanerochaete. The new taxon R. brunnea, from southern Argentina, is described and illustrated. In addition, the new combinations R. americana, R. borneensis, R. filamentosa, R. fouquieriae and R. radicata are proposed. A key to the species of Rhizochaete is provided.

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.

The phylogenetic disposition of Antrodia s.l. (Polyporales, Basidiomycota) from Patagonia, Argentina

The aim of the present study was to characterise species of Antrodia s.l. from Patagonia, Argentina, and to determine their phylogenetic relationships by using morphological and cultural features as well as mating systems and ITS sequences. Phylogenetic trees generated from maximum-parsimony, neighbour-joining and Bayesian-inference analyses showed that the Argentinean collections were distributed inside the following three main clades: (1) ‘Antrodia clade’, with Antrodia ramentacea (Berk. & Broome) Donk as a sole representative; (2) ‘Amyloporia clade’, including Amyloporia nothofaginea Rajchenb. & Gorjon sp. nov. and A. stratosa (J.E.Wright & J.R.Deschamps) Rajchenb., Gorjon & Pildain comb. nov.; and (3) ‘Fibroporia clade’, with Fibroporia vaillantii (DC.) Parmasto and F. gossypium (Speg.) Parmasto. ‘Amyloporia’ and ‘Antrodia clades’ did not have strong molecular support; however, they were well defined with a polyphasic approach when other features such as the number of spore nuclei, mating systems and nuclear behaviour were added. Antrodia includes homothallic to bipolar species, with uni- or binucleate spores and normal nuclear behaviour. Amyloporia includes bipolar to tetrapolar species, with uninucleate spores and heterocytic nuclear behaviour. Fibroporia has strong molecular support and includes tetrapolar species, with uninucleate spores and normal nuclear behaviour. Amyloporia nothofaginea is described as a new species and two new combinations in Amyloporia are proposed. A key to the Antrodia s.l. species present in Patagonia is included.

Molecular phylogeny of Armillaria from the Patagonian Andes

A number of species in the plant pathogen genus Armillaria are known from South America where they cause root rot disease on a wide variety of hosts. Knowledge pertaining to phylogenetic relationships of these species with those of other Armillaria species is almost non-existent. In addition, very few cultures representing these species are available, making DNA-based phylogenetic analyses impossible. The aim of this study was to characterise a collection of Armillaria isolates from the Patagonian Andes using DNA sequences and to determine their phylogenetic relationships with other Armillaria species. DNA sequences were obtained from the internal transcribed regions (ITS1, 5.8S and ITS4) and ribosomal large subunit (LSU) gene and used in phylogenetic analyses. Phylogenetic trees generated from the sequences separated the Armillaria isolates into four lineages. Lineages I and II represented A. novae-zelandiae and A. luteobubalina, respectively. Isolates belonging to A. novae-zelandiae from Malaysia, New Zealand, Australia and South America showed considerable intra-clade sub-structure. Lineages III and IV are probably distinct species and are most closely related to A. hinnulea and an unnamed species isolated from New Zealand and Kenya. This is the first comprehensive study of the phylogenetic relationships of Armillaria species from Patagonia and it provides a foundation for future research in this region.

Nuclear behavior of the mycelium and the phylogeny of Polypores (Basidiomycota)

This is a review of the available knowledge on nuclear behavior of the mycelium within polypore genera (Agaricomycetes, Basidiomycota). Information on 68 genera showed that nuclear behavior is a distinct and consistent feature at genus level and can be coupled with phylogenetic differentiation. The sole exception was found in Polyporus, where different species with normal, heterocytic and astatocoenocytic nuclear behaviors were found. Of the 68 genera treated 41 (60.3%) displayed a normal nuclear behavior, nine (13.2%) were heterocytic, nine (13.2%) were astatocoenocytic and another eight (11.8%) were holocoenocytic. In 95% of the genera a unique compatibility system was found, with the exceptions of Antrodia, which includes both homothallic and bipolar species all associated with a normal nuclear behavior, and Spongipellis, in which bipolar and tetrapolar species are found, all displaying an astatocoenocytic nuclear behavior. Normal and heterocytic nuclear behaviors were associated mostly with tetrapolarity, astatocoenocity was associated mostly with bipolarity, and holocoenocity was associated with either bipolarity or purported homothallism. The combination of nuclear behavior with mating system and brown or white rot capability appeared as a strong feature characterizing and distinguishing the genera of polypores, each combination being valuable to differentiate between apparently related genera, as is supported by phylogenetic studies. Several examples are presented to support this idea, as well as the cases of species that are problematic to this concept. Poroid genera of Hymenochaetaceae were treated apart because of the lack of knowledge regarding their nuclear behavior. In addition new information on the sexuality and/or nuclear behavior of 15 polyporoid taxa is given.

Diversity of Corticiaceae sens. lat. in Patagonia, Southern Argentina

Abstract The diversity of Corticiaceae found in the Patagonian Andes forests of southern Argentina was studied. A total of 168 species of Corticiaceae sens. lat. are recorded. The total diversity of corticioid fungi is estimated to be 250–290 species based on the accumulated increase of taxon diversity on different substrates. Most recorded species (56%) are cosmopolitan or widely distributed, 20% endemic, 4% austral, 17% amphitropical, and 3% show other distributions. The genera Dendrothele and Hyphodontia contain a high number of endemic species. Taxa that are particularly interesting due to their morphological peculiarities and/or their possible phylogenetic relationships are discussed. On the basis of 110 species recorded from Tierra del Fuego, we estimated that about half of these species are very rare and highly vulnerable in that island.

The genus Hyphodontia in the Patagonian Andes forests of Argentina

The genus Hyphodontia is reviewed for southern Argentina from specimens gathered on Nothofagus spp., Austrocedrus chilensis, Drymis winteri, Maytenus magellanica and Berberis ilicifolia. Sixteen species are reported, five of which are new taxa, namely, Hyphodontia crassispora, H. gamundiae, H. hjortstamii, H. magnifica and H. pumilia. A new name and new combinations are proposed for names of species not found in the area but similar to some of the described taxa: Hyphodontia cunninghamii nom. nov., H. subscopinella comb. nov. and H. rickii comb. nov. Several of the new taxa have thick-walled spores that may be cyanophilous and metachromatic. These characters, typical of the genus Hypochnicium, are shown to fit within Hyphodontia, given other mor- phological features typical of the genus, i.e., hyphal features, basidiome construction, and morphology of cystidia and basidia. A dichotomous key to the six- teen taxa in Patagonia is provided.

Taxonomy of Armillaria in the Patagonian forests of Argentina

The taxonomy of Armillaria in southern South America has received little attention since the work of Singer and others. In this study we examine the morphological traits and cultural features for taxa representing the lineages revealed based on molecular phylogeny, and we link them to previously described taxa based on morphology. Lineages I–IV were identified as Armillaria novaezelandiae, A. montagnei, A. umbrinobrunnea comb. nov. and A. sparrei respectively. They could be differentiated morphologically based on dimension, features of the epicutis, annulus, stipe, hymenophoral trama and flavor and characteristics in culture. Furthermore there was no evidence of host preference for the species recognized. This is the first study integrating the phylogeny and morphology of Armillaria species from Patagonia, and it provides a foundation for future research on these fungi in South America.

Influencia del régimen de fertilización y del momento de inoculación en la micorrización de Pinus ponderosa en la etapa de vivero

El presente trabajo tiene como objetivo evaluar la colonizacion micorricica y el crecimiento de plantas de Pinus ponderosa inoculadas con esporas de Rhizopogon roseolus, sometidas a tres niveles de fertilizacion, dos momentos de inoculacion (a dos semanas y a cuatro meses posteriores a la siembra), y dos momentos de cosecha diferentes (a ocho meses y a 10 meses de la siembra luego de un periodo de dos meses con baja fertilizacion llamado periodo de letargo). Se observo que la aplicacion del periodo de letargo aumento significativamente la micorrizacion. Tanto las variaciones en los niveles de fertilizacion utilizados como los distintos momentos de inoculacion no produjeron diferencias significativas en los porcentajes de micorrizacion, bajo el esquema de produccion tradicional