Abstract: Lentinula edodes is the most consumed mushroom in the world, being cultivated mainly on waste coming from the forest industry. During shiitake cultivation, incubation is essential and is usually longer than in other edible mushrooms. This stage includes “browning”, which is a process induced by exposure to a photoperiod and although it is believed to bring certain advantages to shiitake cultivation, it has not been widely studied. In this work, we evaluated how the incubation time, the use of different strains and the induction of browning affect the proximate composition, biological efficiency and other yield parameters of L. edodes. In order to do that, three experiments were carried out with three different strains, three different incubation times and the effect of induction or non-induction of browning. As results we found that the proximate composition did not vary with respect to the different incubation times or from the induction of browning, although differences were found according to the strain. On the other hand, the biological efficiency was affected by the incubation time and the strain used, but not by the induction of browning.

Abstract Agrocybe is characterized by the collybioid to tricholomatoid basidiomata with rusty to dark spore-print, a hymeniform pileipellis, and basidiosspores with a reduced to broad germ-pore. Recently, the species with reduced germ-pore were segregated to Cyclocybe. The knowledge of these genera in Argentina is scanty, although they have been partially studied in the country, but there is not a field that deals exhaustively with it. Macro- and micromorphological characters of specimens obtained in the feld and from different national herbaria (BAFC, CTES, LIL, LPS) were analyzed. Cultivation techniques were used to obtain basidiomata, allowing for a macro- and micromorphological study of fresh developing basidiomes. We concluded that in Argentina there are, so far, 14 species of Agrocybe (one of them with 3 varieties) and two of Cyclocybe including to C. wrightii, which is proposed as a new combination. Sixteen species are described and a key to the Argentinian species of Agrocybe and Cyclocybe is proposed.

Resumen Agrocybe se caracteriza por sus basidiomas collibiodes a tricholomatoides, esporada con coloraciones ferrugineas a oscuras, pileipellis himeniforme y esporas con poro germinativo. Recientemente, las especies con poro germinativo reducido fueron segregadas a Cyclocybe. El conocimiento de estos géneros en Argentina es escaso, aunque hay estudios parciales de varios micólogos, no hay un trabajo que lo trate exhaustivamente en forma conjunta. Se analizaron caracteres macro y micromorfológicos de especímenes colectados y de diferentes herbarios nacionales (BAFC, CTES, LIL, LPS). Se utilizaron técnicas de cultivo para obtener basidiomas, lo que permitió un estudio macro y micromorfológico de material fresco en desarrollo. Concluimos que en Argentina hay, hasta el momento, 14 especies de Agrocybe (una de ellas con tres variedades), y dos especies de Cyclocybe, incluyendo a C. wrightii, la cual es propuesta como una nueva combinación. Se describen dieciséis especies y se propone una clave para las especies argentinas de Agrocybe y Cyclocybe.

Abstract Background: To increase profitability, it can be obtained by increasing yields, productivity or both, and in this way to obtain more fungi with the same effort. Objective: To seek for the optimal inoculation rate to increase the productivity of the culture of a highly productive commercial strain of Pleurotus ostreatus. Methods: Wheat straw was used as a substrate; bags of 1 kg wet weight were inoculated with different percentages of inoculum (produced on sorghum) varying from 1 to 16.6 %. Results and conclusions: Fruit bodies were obtained in all treatments; the incubation time was reduced by one week inoculating at 13 and 16.6 %. We observed an enhance in yields as the percentage of inoculum increased. The highest biological efficiency percentages were reached in the samples inoculated with 13 and 16.6 %, obtaining values of 116.08 and 116.04 % respectively, without showing significant differences between them even though there were differences among treatments. The number of growing cycles per year was increased to 5.5 inoculating to 13-16.6 %. When we evaluated the total kilograms produced in one year and compared them with the cost of the inoculum, the economic balance showed that by using a percentage of 13 %, the producer doubled his profits.

Resumen Antecedentes: El aumento de la rentabilidad en un cultivo puede obtenerse incrementando los rendimientos, la productividad o ambos, de modo de obtener mayor cantidad de hongos con el mismo esfuerzo. Objetivos: Buscar la tasa de inoculación óptima para incrementar la productividad del cultivo de una cepa altamente productiva de Pleurotus ostreatus. Métodos: Usamos como sustrato paja de trigo, se inocularon bolsas de 1 kg peso húmedo con diferentes porcentajes de inóculo (producido sobre sorgo) variando del 1 al 16.6 %. Resultados y conclusiones: Se obtuvieron fructificaciones en todos los tratamientos; el tiempo de incubación se redujo una semana inoculando al 13 y 16.6 %. Observamos un aumento en los rendimientos a medida que aumentaba el porcentaje de inóculo. Los porcentajes de eficiencia biológica más altos se alcanzaron en las muestras con 13 y 16.6 %, obteniéndose valores de 116,08 y 116.04 % respectivamente, sin mostrar diferencias significativas entre ellos, pero si con el resto de los tratamientos. El número de ciclos de cultivo por año se incrementó a 5.5. Cuando evaluamos los kilogramos totales producidos en un año y los comparamos con el costo del inóculo, el balance económico muestra que al usar un porcentaje del 13 %, el productor casi duplica sus ganancias.

Abstract Three species of Volvariella from Northern Argentina are illustrated and described. Volvariella taylorii, known from the Yungas and the Paranaense Rain Forests; V. subxerophytica, known exclusively from the xerophytic forest from "chaqueña" region, and V. pusilla which was found in Chaco and Tucumán provinces. The two former species are characterized by having brownish-grayish volva and the fibrillose pileus, and the later by its whitish-grayish volva and the finely and delicately fibrillose surface of the pileus. Volvariella taylorii is recorded for the first time from Argentina and the area of distribution of V. subxerophytica is expanded towards the oriental area of the "chaqueña" region. It is important to mention that V. subxerophytica was only known by the type material and that in this work the original description is improved with data obtained from new specimens.

Resumen Se describen e ilustran tres especies de Volvariella para el Norte de la Argentina: V. taylorii, conocida para las selvas de Yungas y Paranaense; V. subxerophytica, conocida exclusivamente para los bosques xerófilos de la región chaqueña y V. pusilla encontrada en las provincias del Chaco y Tucumán. Las dos primeras se caracterizan por poseer volva castaña grisácea y superficie del píleo fibrillosa mientras que la última se caracteriza por su volva blanca grisácea y superficie del píleo glabra a muy delicadamente fibrillosa. Se registra por primera vez para Argentina a V. taylorii y se amplía el área de distribución de V. subxerophytica para el sector oriental de la región chaqueña. Es importante destacar que V. subxerophytica era conocida sólo por el material tipo y mediante los nuevos ejemplares hallados fue posible mejorar la descripción original.

Mycena paranaensis and M. leaiana are very similar species from section Cespitosae, which have been confused by different authors. The aim of this paper is to clarify the species limits between M. leaiana and M. paranaensis. Mycena paranaensis is recorded for the first time for the Argentinean mycobiota, whereas M. leaiana is excluded.

Mycena paranaensis y M. leaiana son dos especies muy similares pertenecientes a la sección Cespitosae, que han sido confundidas por diversos autores. En el presente trabajo se esclarecen los límites específicos entre Mycena leaiana y M. paranaensis. Mycena paranaensis se registra por primera vez para la micobiota argentina, mientras que se excluye a M. leaiana queda excluida.

Marasmiellus volvatus is a small but striking species which was found only few times in the world. It is characterized by its white basidiomata, sulcate pileus, lacking intervenous lamellae and stipe with a volva at the base. Marasmiellus coilobasis is a close species which differs from M. volvatus because of the presence of intervenous lamellae and larger pleurocystidia and spores. Marasmiellus volvatus is described and illustrated. Also an identification key to the species of section Candidi is presented. This is the first report of M. volvatus in Argentina and is the southernmost record reported of the species.

Marasmiellus volvatus es una especie pequeña, pero llamativa, que se encuentra pocas veces registrada en el mundo. Se caracteriza por sus basidiomas completamente blancos, píleo sulcado, láminas sin intervenosas y estípite con una volva en la base. La especie más próxima, M. coilobasis , se diferencia por la presencia de láminas con intervenosas y por los pleurocistidios y esporas de mayor tamaño. Esta es la primera cita de M. volvatus para Argentina, y es el registro más austral de la especie. En este trabajo se describe e ilustra a M. volvatus y se presenta una clave de identificación de la sección Candidi con las especies más próximas.

Trichoderma spp is the cause of the green mold disease in mushroom cultivation production. Many disinfection treatments are commonly applied to lignocellulose substrates to prevent contamination. Mushroom growers are usually worried about the contaminations that may occur after these treatments during handling or spawning. The aim of this paper is to estimate the growth of the green mold Trichoderma sp on lignocellulose substrates after different disinfection treatments to know which of them is more effective to avoid contamination during spawning phase. Three different treatments were assayed: sterilization (121 ºC), immersion in hot water (60 and 80 ºC), and immersion in alkalinized water. Wheat straw, wheat seeds and Eucalyptus or Populus sawdust were used separately as substrates. After the disinfection treatments, bagged substrates were sprayed with 3 mL of suspension of conidia of Trichoderma sp (10(5) conidia/mL) and then separately spawned with Pleurotus ostreatus or Gymnopilus pampeanus. The growth of Trichoderma sp was evaluated based on a qualitative scale. Trichoderma sp could not grow on non-sterilized substrates. Immersions in hot water treatments and immersion in alkalinized water were also unfavorable treatments for its growth. Co- cultivation with mushrooms favored Trichoderma sp growth. Mushroom cultivation disinfection treatments of lignocellulose substrates influence on the growth of Trichoderma sp when contaminations occur during spawning phase. The immersion in hot water at 60 ºC for 30 min or in alkalinized water for 36 h, are treatments which better reduced the contaminations with Trichoderma sp during spawning phase for the cultivation of lignicolous species.

Five new species of Pouzarella are described from northern Argentina, P. brunneonigrescens, P. olivacea, P. parvispora, P. sulcata and P. variabilis. Pouzarella ferreri var. ferreri is also reported for the first time from Argentina. All known Pouzarella species reported from Argentina are discussed and a key to species is provided.

Se describen e ilustran cinco nuevas especies de Pouzarella del norte argentino, P. brunneonigrescens, P. olivacea, P. parvispora, P. sulcata y P. variabilis. Pouzarella ferreri var. ferreri es citada por primera vez para la Argentina. Se discuten todas las especies conocidas de Pouzarella para la Argentina y se propone una clave para su identificación.

This is the first record of Mycena holoporphyra for the Argentinean mycobiota. We describe and illustrate this especies, and discuss differences with its closest taxa. A key to the species of Mycena sect. Calodontes subsect. Purae from Argentina is also included.

Este es el primer registro de Mycena holoporphyra para la micobiota Argentina. Se describe e ilustra esta especie, se analizan las diferencias con las especies cercanas, y se incluye una clave para identificar las especies de Mycena sect. Calodontes subsect. Purae de la Argentina.

A compiled check list of gasteroid fungi of Catamarca Province (Argentina) was made. It was based on literature records, available until April 2010. There were 43 species of fungi distributed in 2 orders, 4 families and 13 genera. The number of species recorded in this area was relatively poor but it is likely to increase with the study of unexplored areas not yet surveyed as the phytogeographical regions of the Puna and Yungas.

Se realiza un listado de los hongos gasteroides de la provincia de Catamarca (Argentina) basado en la bibliografía hasta abril de 2010. En total aparecen citadas 43 especies distribuidas en 2 órdenes, 4 familias y 13 géneros. El número de especies catalogadas es relativamente baja pero este número probablemente se incremente cuando se estudien las zonas aún no muestreadas como son las regiones fitogeográfícas de la Puna y las Yungas.

Fifteen species of Agaricales recently collected from the Argentinian Paranaense rainforest are described and illustrated. Cystolepiota adulterina is a new record from South America whereas Mycena subtenerrima is a new record from Argentina. Clitocybe aprilis, C. asema, C. melliolens, C. subhygrophanoides, Collybia platensis, Crepidotus calolepis ssp. tigrensis, Cyptotrama asprata, Lentinellus angustifolius, Mycena leaiana, Panaeolus subbalteatus, Resupinatus applicatus, R. striatulus y Stropharia semiglobata are new records from the province of Misiones.

Se ilustran y describen 15 especies de Agaricales recientemente recogidos en la selva Paranaense Argentina. Cystolepiota adulterina es una nueva cita para Sudamérica, Mycena subtenerrima es una nueva cita para la Argentina y Clitocybe aprilis, C. asema, C. melliolens, C. subhygrophanoides, Collybia platensis, Crepidotus calolepis ssp. tigrensis, Cyptotrama asprata, Lentinellus angustifolius, Mycena leaiana, Panaeolus subbalteatus, Resupinatus applicatus, R. striatulus y Stropharia semiglobata constituyen nuevas citas para la provincia de Misiones.

Mushrooms are not usually included in the traditional eating habits of the Argentinean population. Nevertheless, there are some people that consume wild species. This practice has caused poisoning to important number of adults and children over the last years. In the present paper we describe the poisonous mushroom Amanita pantherina as a new record for Argentina and we provide a key for the identification of the species of Amanita belonging to Secc. Amanita found in our country. We also describe and explain a new poisoning syndrome caused by Tricholoma equestre. This species was recently prohibited in some countries of Europe.

Si bien los hongos comestibles en la Argentina no constituyen una parte importante de la dieta, algunas personas colectan y consumen especies silvestres. Esto ha ocasionado en los últimos años la intoxicación de un número importante de adultos y niños. En el presente trabajo se cita por primera vez para la Argentina el hongo tóxico Amanita pantherina, se describen las colecciones halladas y se provee una clave para la determinación de las especies de Amanita Secc. Amanita. A su vez se describe y se reevalúa la comestibilidad de Tricholoma equestre causante de un nuevo síndrome de intoxicación, por lo cual fue recientemente prohibido en varios países de la comunidad Europea.