María Belén Pildain

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.

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.

The phylogenetic position of poroid Hymenochaetaceae (Hymenochaetales, Basidiomycota) from Patagonia, Argentina

Six poroid Hymenochaetaceae from Patagonia, Argentina, were studied phylogenetically with nuc rDNA internal transcribed spacer (ITS) and partial 28S rDNA sequences, together with morphological data. Two new genera and a new species are introduced as well as two new combinations proposed. Arambarria destruens gen. et sp. nov. is proposed for a taxon fruiting on fallen or standing, dead Diostea juncea and Lomatia hirsuta and previously recorded erroneously as Inocutis jamaicensis; it is distinguished by annual, effused to effused-reflexed basidiomes forming pilei, a monomitic hyphal system, thick-walled and yellowish basidiospores (brownish chestnut in potassium hydroxide solution), lack of a granular core in the context and lack of setoid elements. Nothophellinus gen. nov. is proposed to accommodate Phellinus andinopatagonicus, the main white wood-rotting polypore of standing Nothofagus pumilio and also an important wood-decayer of other Nothofagus species from southern Argentina and Chile. It is morphologically similar to Phellopilus (type species P. nigrolimitatus) but differs by lacking setae. The new combinations Pseudoinonotus crustosus and Phellinopsis andina are proposed for Inonotus crustosus and Phellinus andinus, respectively. Phellinus livescens, which decays the sapwood of several standing Nothofagus species, is closely related to Phellinus uncisetus, a Neotropical species related to Fomitiporia; for the time being P. livescens is retained in Phellinus sensu lato. An unidentified taxon responsible for a white heart-rot in living Austrocedrus chilensis grouped with Phellinus caryophyllii and Fulvifomes inermis, but its generic affinities remain ambiguous. Transmission electron microscopy studies confirm this unidentified taxon has an imperforate parenthesome, which is typical of the Hymenochaetaceae.

The phylogenetic position of Postia s.l. (Polyporales, Basidiomycota) from Patagonia, Argentina

We investigated the phylogenetic relationships of Postia species from Patagonia with rDNA ITS and LSU sequences, together with morphological, cultural and biological features. All species in the genus were included in a “Postia clade” irrespective of whether their spores were thin- or thick-walled. This clade is characterized by tetrapolar mating, a normal nuclear behavior, metachromatic generative hyphae and absence of fiber hyphae in culture. One subclade merged the austral taxa P. pelliculosa and P. punctata, but otherwise no distinct relationships were found regarding spore shape, spore wall thickness and geographical distribution of taxa. The austral P. venata and the endemic P. carbophila, with thin-walled basidiospores, occupied variable positions in both analyses. Postia caesia from Patagonia grouped within the P. caesia species complex but on a separate branch. In contrast, P. rennyi and P. balsamea from Patagonia corresponded well with strains from other geographic areas. The two austral species in Ryvardenia, R. cretacea and R. campyla, characterized by non-metachromatic hyphae, bipolar mating and an astatocoenocytic nuclear behavior, formed an independent subclade among the dimitic genera of the “Antrodia clade”, far from other Postia taxa within which they had been placed previously, supporting their inclusion in a genus of their own. Postia carbophila grouped with other Postia species and not with Postia (Rhodonia) placenta as suggested previously on the basis of morphological comparisons. Instead, the latter species grouped with taxa in the dimitic genus Amyloporia with which it shares heterocytic nuclear behavior. A separation between specimens of Postia pelliculosa and Ryvardenia cretacea from either side of the Pacific (i.e. SE Australia/New Zealand and S Argentina/S Chile) suggests they could be considered different at the species level from a phylogenetic point of view.

Phylogenetic relationships of Hydnum peroxydatum support the synonymy of Hydnochaete with Hymenochaete (Hymenochaetaceae, Agaricomycetes).

A combined dataset of rDNA ITS and LSU sequences was used to infer the phylogenetic relationships of Hydnochaete peroxydata (≡ Hydnum peroxydatum), the type species of Hydnochaete. The species was retrieved nested within the Hymenochaete s. str. clade; therefore Hydnochaete is regarded as a synonym of Hymenochaete and the new combination Hymenochaete peroxydata is proposed.

A discussion on the genus Fomitiporella (Hymenochaetaceae, Hymenochaetales) and first record of F. americana from southern South America

Abstract Fomitiporella has traditionally been delimited based on the gross morphology of the basidiomes, hyphal structure and basdiospores. Recently, phylogenetic studies supported the incorporation of an extensive number of species within the genus. Although most of its species are nested in the ‘Phellinotus clade’ (Hymenochaetaceae, Basidiomycota), genera such as Arambarria, Inocutis and Phellinotus were not included in previous analysis. To further our understanding of the genus, new sequences from 28S and ITS nuc rDNA genes were jointly analysed with a large selection of taxa in the ‘Phellinotus clade’, also with re-examination of morphological and ecological data. Results showed several lineages in what has hitherto been considered to represent Fomitiporella, indicating that the genus is paraphyletic as presently circumscribed. There is a well-supported Fomitiporella core group that includes the type species and nine other monophyletic lineages with high support, of which those representing Arambarria, Inocutis and Phellinotus are distinct from the Fomitiporella core group by macro and micromorphological traits and/or biogeographic distribution. Fomitiporellaamericana, a species described from SE USA, was found in the Patagonian forests of southern Argentina and Chile; it is the taxon responsible for the white heart-rot found on standing Austrocedruschilensis and one of the taxa decaying wooden tiles of historic churches in Chiloé Is., Chile.

Patagonian Antagonist Yeasts for Food Biopreservation

Worldwide, microbial growth destroys large amounts of various products, causing yield losses in the agronomical and biotechnological industries. Traditionally, biocides have been used to manage these problems, but different disadvantages such as the establishment of resistant strains and the suppression of natural competitors have made alternatives such as biological control necessary. After harvest, many fruits are kept in cold storage to prolong their availability and shelf life. Often, this requires the application of a chemical fungicide to prevent postharvest decay from decay fungi. An alternative approach for preventing postharvest fungal decay during storage could be based on the treatment of the commodity with antagonistic yeasts. In this regard, the use of cold-adapted yeasts may offer a distinct advantage. Numerous cold-adapted yeasts species have been isolated from artificial cold environments, as well as cold-stored fruits. Recently, we isolated and identified epiphytic yeasts during the cold postharvest storage of pears and fine fruits from packinghouses in Argentinean Patagonia, and we tested their efficacy in controlling the postharvest diseases of different fruits caused by several pathogens. Additionally, killer yeasts as producers of mycocins or killer toxins that can neutralize the activities of spoilage yeasts in wines represent an interesting biocontrol strategy. Several screening studies focused to determine the occurrence of killer yeasts in winemaking environments have been carried out, and they have demonstrated the presence of killer phenotypes in yeasts from wines, cellar surfaces, and winery equipment. In previous studies carried out in our laboratory, most yeasts isolated from spontaneously fermenting grape musts evidenced killer character. These studies provide an exceptional source of potential antagonist yeasts to be used in biocontrol of undesired microorganisms in wine. Nonetheless, it is necessary to continue to identify new potential microorganisms and to develop a better understanding of the biology of yeast biocontrol systems to increase the potential of postharvest biocontrol as a viable alternative to synthetic postharvest fungicides and chemical preservatives against wine spoilage yeast.

Fruit rot of sweet cherries and raspberries caused by Penicillium crustosum and Mucor piriformis in South Patagonia, Argentina

Abstract Cherries and raspberries are important fruit crops in Patagonia, Argentina. A high proportion (50%) of raspberry production is organic certified and sold for fresh and frozen domestic markets. Due to post-harvest rot diseases, cherries and raspberries from Patagonia are kept in cold storage for a short period of time. During the storage season of 2012–2013, fruit rot samples were obtained from conventional and organic sweet cherry and raspberry orchards in the Andean zone of Central Patagonia. Penicillium crustosum and Mucor piriformis were isolated from both types of production systems and identified through morphological and molecular analysis; their pathogenicity was confirmed based on their virulence (incidence and severity). To our knowledge, this is the first report confirming Penicillium crustosum and Mucor piriformis causing post-harvest disease on cherries and raspberries in Argentina, and it contributes to expanding the knowledge on emerging pathogens.

Efecto del potencial agua y de la defensa primaria del hospedante sobre el crecimiento de Amylostereum areolatum y A. chailletii, simbiontes fúngicos de los sirícidos, y estudio de la micobiota asociada a la madera de coníferas en Patagonia, Argentina

Amylostereum areolatum y A. chailletii son los simbiontes fungicos de las avispas barrenadoras de la madera Sirex noctilio y Urocerus gigas, respectivamente. Las especies de Pinus, son susceptibles al ataque del patosistema S. noctilio - A. areolatum, no obstante en Patagonia, se ha observado que la madera apeada de Pseudotsuga menziesii puede ser atacada por U. gigas y su simbionte. En este estudio se evaluo la relacion de A. areolatum, A. chailletii y el potencial agua (ψ0), la defensa primaria de Pinus ponderosa y Pseudotsuga menziesii, y la micobiota endofitica asociada a ambas coniferas. Los ψ0 se generaron por variacion del potencial osmotico; se extrajeron y caracterizaron por GC y GC-MS los aceites esenciales de las oleorresinas constitutivas de la corteza y la albura de ambas coniferas y se evaluo el efecto de compuestos diferenciales y mayoritarios sobre el crecimiento de ambos hongos; la micobiota se analizo a partir de aislamientos de la albura de plantas sanas. Se observo que, el crecimiento de ambos hongos se ve significativamente afectado por el decrecimiento del ψ0 y que A. chailletii crecio mas que A. areolatum en ψ0 mas bajos. Las oleorresinas tuvieron un efecto negativo sobre el crecimiento de ambos hongos sin observarse diferencias entre compuestos diferenciales de cada conifera. Hormonema dematioides fue el endofito mas frecuente en P. menziesii, ya caracterizado por su influencia sobre el crecimiento de otros hongos, se presenta como una variable a considerar en cuanto al establecimiento del patosistema S. noctilio- A. areolatum.