Summary Background and aims : A list of mosses recorded in Punta Lara Natural Reserve (Buenos Aires, Argentina) is presented, increasing the knowledge of the diversity and distribution of mosses in the country. M&M : The specimens were collected and identified according to conventional taxonomic criteria and deposited in the Herbarium of the Spegazzini Institute (LPS). Global Biodiversity Information Facility (GBIF) records were consulted as a source of information about the species distribution. Results : Fifteen species of mosses distributed in 11 families were identified in Punta Lara Natural Reserve. The genus Thamnomalia Olsson, Enroth & Quandt, represented by Thamnomalia glabella (Hedw.) Olsson, Enroth & Quandt and the species Sematophyllum adnatum (Michx.) E. Britton are recorded for the first time for Argentina. Discussion and Conclusions : Two species are new records for Argentina and 11 species are recorded for the first time for Buenos Aires province. Several species are tropical, extending their distribution towards temperate regions.

Resumen Introducción y objetivos : Se presenta una lista de musgos registrados en la Reserva Natural Punta Lara (Buenos Aires, Argentina) con el objetivo de ampliar el conocimiento sobre la distribución de las especies presentes en el país. M&M : Los especímenes fueron recolectados e identificados de acuerdo a los criterios taxonómicos convencionales y depositados en el Herbario del Instituto Spegazzini (LPS). Registros del Servicio de Información sobre la Diversidad Biológica Mundial (GBIF) fueron consultados como fuente de información sobre la distribución de las especies. Resultados : Como resultado de este estudio se identificaron 15 especies de musgos pertenecientes a 11 familias en la Reserva Natural Punta Lara. Se cita por primera vez para Argentina la especie Sematophyllum adnatum (Michx.) E. Britton y el género Thamnomalia Olsson, Enroth & Quandt, representado por Thamnomalia glabella (Hedw.) Olsson, Enroth & Quandt. Discusión y Conclusiones : En este trabajo se registran dos nuevas citas para la Argentina y 11 nuevas menciones para la provincia de Buenos Aires. Varias de las especies recolectadas son tropicales, ampliando su distribución hacia regiones templadas.

ABSTRACT This study aimed to analyse the effects of invasion by the exotic Ligustrum lucidum on mycorrhizal associations in forests of Celtis tala, and to determine the role that these fungi play in the invasion process. We analyzed colonization and response to mycorrhization of both plant species under greenhouse conditions after inoculation with soil obtained from patches of non-invaded native forests and invaded forests. The spores present in pots at the end of the experiment were counted and identified. Colonization of L. lucidum was greater in plants inoculated with invaded forest soil, whereas colonization of C. tala was greater in plants inoculated with non-invaded native forest soil. Principal component analysis of fungal species abundance showed differences in AMF composition according to host plant and forest type. The results show that L. lucidum establishes symbiosis with native AMF, which triggers changes in community structure. These changes favored the mycorrhization of L. lucidum and interfered with the mycorrhization of C. tala. AMF may have either a direct or indirect role in the invasion process, not only benefiting the invasive species but also preventing the regeneration of native plants.

Abstract This study analysed the mycobiota on exoskeleton debris of the crab Neohelice granulata collected from an alkaline salt marsh and assessed the in vitro enzyme ability of selected isolates at different temperatures and pH. Exoskeleton fragments were incubated in moist chambers on paper and on agar medium. Growth and enzyme ability of selected fungi were also evaluated in agar media with 0.5 % casein, 1% Tween®20, and Chitin-Azure® by the production of a halo/growth ratio. We identified 22 fungal species using both methods. Since the two isolation methods added information to one another, both ones are necessary to recover the cultivable mycobiota associated with the exoskeleton debris. All fungi showed greater levels of enzyme activity in alkaline than acid medium with Tween®20. The halo diameter on casein and chitin varied according to the fungal isolate and pH. Most fungi had a larger halo at 4°C than at the other temperatures tested. Clonostachys rosea showed the greatest activity in all media at 4ºC. We conclude that exoskeletons of the N. granulata are a source of fungi able to produce enzyme activities that show differences upon incubation conditions to which they are cultivated such as ones including specific temperatures and pH values.

Resumen Introducción: La expansión e intensificación de la agricultura provoca profundos cambios a escala mundial, lo que genera un fuerte impacto en la productividad de los cultivos y, en consecuencia, una disminución de la biodiversidad asociada. Ilex paraguariensis, conocida como yerba mate, es una especie nativa de América del Sur y se ha introducido en el mercado mundial (por ejemplo, Medio Oriente, Europa y Estados Unidos) debido a sus múltiples beneficios nutricionales y propiedades antioxidantes. La asociación de plantas de I. paraguarensis con hongos arbusculares (AMF), especialmente en condiciones de campo, ha sido escasamente documentada. Objetivo: El objetivo de este trabajo fue evaluar estacionalmente durante un período de 2 años: la composición de especies, la riqueza, la densidad de esporas y la diversidad de las comunidades Glomeromycota de yerba mate en diferentes cultivos y condiciones naturales. Métodos: Se extrajeron muestras de suelo en invierno y verano de cinco sitios productivos con condiciones de cultivo (situaciones 1-5), en contraste conal manejo histórico como situación de referencia (situación 6). Las esporas se identificaron siguiendo criterios morfológicos. Resultados: Acaulosporaceae y Glomeraceae presentaron las mayores densidades de esporas en todos los sitios de muestreo / estaciones / años. El índice más bajo de densidad y diversidad de esporas se registró en 2014, cuando las precipitaciones fueron más altas que en 2013. Discusión: Se registra por primera vez para América del Sur a Acaulospora capsicula identificada por caracteres morfológicos. Las diferencias entre años podrían atribuirse a las precipitaciones. Este estudio contribuye al conocimiento de la dinámica y los factores que influyen en la estructura de las comunidades AMF a lo largo del tiempo. Esta información sería valiosa para generar estrategias de conservación para este grupo de microorganismos, que son clave para el desarrollo sostenible de los sistemas de cultivo de yerba mate.

Abstract Introduction: The expansion and intensification of agriculture causes profound changes at a global scale, which generates a strong impact on crop productivity and consequently, a decrease in the biodiversity associated. Ilex paraguariensis, known as yerba mate, is a native species from South America and it has been introduced in the world market (e.g. Middle East, Europe, and United States) due to its multiple nutritional benefits and antioxidant properties. The association of plants of I. paraguarensis with arbuscular mycorrhizal fungi (AMF), especially under field conditions, has been scarcely reported so far. Objective: The aim of this work was to assess the species composition, richness, spore density and diversity of Glomeromycota communities of yerba mate under different crop and natural conditions, seasonally over a 2-year period. Methods: Soil samples were extracted in winter and summer from five productive sites (situations 1-5), with contrasting crop conditions with regard to historical management, as a reference situation (situation 6). Spores were identified following morphological criteria. Results: Acaulosporaceae and Glomeraceae presented the highest spore densities in all sampling sites/ seasons/years. The lowest spore density and diversity index was recorded in 2014, when rainfall was higher than in 2013. Discussion: We reported Acaulospora capsicula detected by morphological analysis, for the first time in South America. Differences between years could be attributed to rainfall. This study contributes to the knowledge of the dynamics and factors that influence the structure of AMF communities over time. This information would be valuable to generate conservation strategies for this group of microorganisms, which are key to the sustainable development of yerba mate cultivation systems.

Arbuscular mycorrhizal fungi (AMF) increase the uptake of soluble phosphates, while phosphorus solubilizing fungi (S) promote solubilization of insoluble phosphates complexes, favoring plant nutrition. Another alternative to maintaining crop productivity is to combine minerals and rocks that provide nutrients and other desirable properties. The aim of this work was to combine AMF and S with pyroclastic materials (ashes and pumices) from Puyehue volcano and phosphate rocks (PR) from Rio Chico Group (Chubut) - to formulate a substrate for the production of potted Lactuca sativa. A mixture of Terrafertil®:ashes was used as substrate. Penicillium thomii was the solubilizing fungus and Rhizophagus intraradices spores (AMF) was the P mobilizer (AEGIS® Irriga). The treatments were: 1) Substrate; 2) Substrate + AMF; 3) Substrate+S; 4) Substrate + AMF+ S; 5) Substrate: PR; 6) Substrate: PR + AMF; 7) Substrate: PR + S and 8) Substrate: PR + AMF + S. Three replicates were performed per treatment. All parameters evaluated (total and assimilable P content in substrate, P in plant tissue and plant dry biomass) were significantly higher in plants grown in substrate containing PR and inoculas with S and AMF. This work confirms that the combination of S/AMF with Puyehue volcanic ashes, PR from the Río Chico Group and a commercial substrate promote the growth of L. sativa, thus increasing the added value of national geomaterials.

Los hongos micorrícicos arbusculares (HMA) incrementan la toma de fosfatos solubles, mientras que los hongos solubilizadores de fósforo (S) promueven la solubilización de complejos insolubles de fosfato, en conjunto benefician la nutrición de las plantas. La utilización de estos organismos en combinación con minerales o rocas que aportan nutrientes es otra alternativa para mantener la productividad de los cultivos. El objetivo de este trabajo fue combinar HMA y S con materiales piroclásticos (cenizas y pumicitas) del volcán Puyehue y rocas fosfóricas (RP) del Grupo Río Chico (Chubut) y evaluar el desempeno de estas mezclas como sustratos para la producción en maceta de Lactuca sativa. Para formular los sustratos, se utilizó como base una mezcla de Terrafertil® con cenizas. Penicillium thomii fue el S y esporas del hongo Rhizophagus intraradices (AEGIS® Irriga) sirvieron de fuente del HMA. Se evaluaron diversas combinaciones de microorganismos y la adición o no de RP. Los tratamientos fueron: 1) sustrato; 2) sustrato + HMA; 3) sustrato + S; 4) sustrato + HMA + S; 5) sustrato: RP; 6) sustrato: RP + HMA; 7) sustrato: RP + S, y 8) sustrato: RP+ HMA + S. Se efectuaron 3 repeticiones por tratamiento. Los parámetros evaluados fueron el contenido de P total y asimilable en el sustrato, el P en el tejido vegetal y la biomasa seca. Todos ellos fueron significativamente mayores en las plantas que crecieron en el sustrato adicionado con RP e inoculadas con S y HMA. Este trabajo confirma que la combinación S/HMA con cenizas volcánicas del Puyehue y las RP del Grupo Río Chico formuladas con un sustrato comercial promueven el crecimiento de L. sativa. De este modo es posible incrementar el valor agregado de geomateriales de origen nacional.

In this article, the state of art of the mycology in Argentina is highlighted, with the purpose of reviewing the advances that allowed positioning this discipline worldwide. It reviews the main areas of research, laboratories recognized, and the researchers for the country.

En este artículo se presenta el estado del arte de la micología en la Argentina con el propósito de reseñar los avances que permitieron posicionar esta disciplina a nivel mundial. Se presentan las principales áreas de investigación micológica, los laboratorios reconocidos y los investigadores para el país.

ABSTRACT Knowledge of the occurrence and diversity of arbuscular mycorrhizal fungi (AMF) in National Parks is essential for the establishment of policies for conservation. The aim of this study was to characterize the AMF communities in the Patagonian Altoandina region in Nahuel Huapi National Park, Argentina. We surveyed AMF spores associated with the rhizospheres of 9 plant species in the Patagonian Steppe (PS), Challhuaco Hill (ChH), Catedral Hill (CH), and Tronador Hill (TH) regions and detected a total of 27 Glomeromycota species. Acaulospora laevis was dominant at all sites. The AMF community was dominated by Acaulosporaceae, as regards the number of species and contribution of each one to the total number of spores. Three Glomeromycota families were detected at PS, the site with the lowest elevation; whereas five to six families were detected at ChH, CH, and TH. Cluster analysis indicated that the AMF communities were grouped according to habitat. We concluded that certain patterns of the AMFcommunity structure detected were equivalent to those of high-altitude environments from other studies, while others were unique to the Patagonian region; thus suggesting that historical influences like dispersion and speciation played a critical role in shaping AMF community composition in such high-altitude environments.

Endophytic fungi are ubiquitous and live within host plants without causing any noticeable symptoms of disease. Little is known about the diversity and function of fungal endophytes in plants, particularly in economically important species. The aim of this study was to determine the identity and diversity of endophytic fungi in leaves, stems and roots of soybean and corn plants and to determine their infection frequencies. Plants were collected in six areas of the provinces of Buenos Aires and Entre Ríos (Argentina) two areas were selected for sampling corn and four for soybean. Leaf, stem and root samples were surface-sterilized, cut into 1 cm² pieces using a sterile scalpel and aseptically transferred to plates containing potato dextrose agar plus antibiotics. The species were identified using both morphological and molecular data. Fungal endophyte colonization in soybean plants was influenced by tissue type and varieties whereas in corn plants only by tissue type. A greater number of endophytes were isolated from stem tissues than from leaves and root tissues in both species of plants. The most frequently isolated species in all soybean cultivars was Fusarium graminearum and the least isolated one was Scopulariopsis brevicaulis. Furthermore, the most frequently isolated species in corn plants was Aspergillus terreus whereas the least isolated one was Aspergillus flavus. These results could be relevant in the search for endophytic fungi isolates that could be of interest in the control of agricultural pests.

Los hongos endófitos son ubicuos y se encuentran en el interior de los tejidos de las plantas de manera asintomática. Se sabe muy poco acerca de la diversidad y la función de estos hongos, particularmente en especies de importancia económica. El objetivo de este trabajo fue determinar la diversidad y la frecuencia de colonización de hongos endófitos en raíces, tallos y hojas de 2 variedades de maíz y de 4 variedades de soja; las muestras se tomaron de 6 áreas diferentes ubicadas en las provincias de Buenos Aires y Entre Ríos (Argentina). Con un bisturí estéril se obtuvieron porciones de 1 cm² de raíz, tallo y hoja, que fueron colocados en placas con agar papa dextrosa más antibiótico. Las especies de hongos fueron identificadas a partir de características morfológicas y moleculares. La colonización de hongos endófitos en soja estuvo influenciada por la variedad y por el tipo de tejido, en tanto que en el maíz solo hubo influencia del tipo de tejido. El mayor número de endófitos se encontró en los tallos de ambas especies. El aislamiento más frecuente en todas las variedades de soja fue Fusarium graminearum y el menos frecuente Scopulariopsis brevicaulis. En ambas variedades de maíz la especie con mayor frecuencia de aislamiento fue Aspergillus terreus y la de menor fue Aspergillus flavus. Estos resultados son relevantes para la búsqueda de especies de hongos endófitos que podrían ser de interés en el control de plagas agrícolas.

Arbuscular mycorrhizal fungi (AMF) colonize approximately 82% of land plants in every ecosystem, even in extreme conditions such as saline soils. In the present work we report the arbuscular mycorrhizal colonization and its vertical root concentration in four Chenopodiaceae plants species (Allenrolfea patagonica, Atriplex argentina, Heterostachys ritteriana and Suaeda divaricata) at five different soil depths in two salines of central Argentina. All the plant species showed mycorrhizal colonization and varied significantly among plant species and sites for all soil depths. Atriplex argentina presented the highest mycorrhizal colonization at almost all soil depths (0-50 cm). In all plant species root concentration decrease as depth increases at both sites. The presence of mycorrhizal roots in the deeper layers of soil in the four Chenopodiaceae plants species, shows that these fungi are tolerant to live in the saline soils of central Argentina.

Los hongos micorrícico-arbusculares (HMA) colonizan aproximadamente el 82% de las plantas terrestres en cualquier ecosistema, aún en condiciones extremas tales como los suelos salinos. En el presente trabajo se reporta la colonización micorrícica arbuscular (CMA) y su concentración radical en cuatro especies de Chenopodiaceae (Allenrolfea patagonica, Atriplex argentina, Heterostachys ritteriana y Suaeda divaricata) en cinco profundidades del suelo en dos salinas del Centro de Argentina. Todas las plantas mostraron colonización micorrícica que varió significativamente entre especies y sitios para todas las profundidades. Atriplex argentina presentó el mayor porcentaje de CMA en casi todas las profundidades (0-50 cm). En todas las especies, la concentración radical disminuyó a medida que se incrementó la profundidad en ambos sitios. La presencia de raíces micorrizadas en las capas más profundas del suelo para las cuatro especies de Chenopodiaceae, muestran que estos hongos son tolerantes a vivir en los suelos salinos del centro de Argentina.

The morphologic features of Talaromyces udagawae Stolk and Samson are here described and illustrated. This teleomorphic Ascomycota fungus was isolated from soil obtained in Buenos Aires province (Argentina) from beneath a human cadaver in an advanced state of decomposition. After washing and serial dilution of the soil along with moist-chamber techniques for fungal cultivation, T. udagawae formed very restricted colonies of bright yellow color on different growth media with 8-ascospored asci. The ascospores were ellipsoidal and ornamented. The anamorphic state was not observed. Molecular-genetic techniques identified the species. The present record is the first of the species in Argentina, pointing it as a tool to identify soils where cadaver decomposition occurs.

Se describen e ilustran las características morfológicas de Talaromyces udagawae Stolk y Samson. Se aisló el estado teleomórfico de este hongo Ascomycota de suelo obtenido en la provincia de Buenos Aires (Argentina), por debajo de un cadáver humano en avanzado estado de descomposición. Las muestras de suelo fueron analizadas mediante lavado, dilución seriada y cámaras húmedas, técnicas ampliamente usadas para el estudio de hongos de suelo. T. udagawae formó colonias muy restringidas de color amarillo brillante en diferentes medios de cultivo, con ascos con 8 ascosporas. Las ascosporas eran elipsoidales y ornamentadas. No fue hallado el estado anamórfico. La especie también fue identificada mediante técnicas moleculares. El presente registro es el primero de la especie en la Argentina y el único que la postula como herramienta para identificar suelos donde ocurre una descomposición cadavérica.

The plant-parasitic nematode Nacobbus aberrans is an endoparasite that induces gall formation in the roots and causes severe losses to diverse crops. Some populations of this nematode show preference for certain hosts, revealing the existence of "races/groups" with different behaviour and making nematode management difficult. A possible biological control alternative to reduce the damage caused by this species may be the use of arbuscular mycorrhizal fungi (AMF). In the present work, the effect of Glomus intraradices on tomato plants inoculated with the nematode at transplanting and three weeks later was tested. At 60 days, the following parameters were estimated: percentage of AMF colonization, root and aerial dry weight, number of galls and egg masses, and reproduction factor (RF=final population/initial population) of N. aberrans. AMF colonization was higher in the presence of the nematode. The use of AMF favoured tomato biomass and reduced the number of galls and RF on the plants inoculated with the nematode at transplanting.

Arbuscular mycorrhizal fungi (AMF) colonize land plants in every ecosystem, even extreme conditions such as saline soils. In the present work we report for the first time the mycorrhizal status and the vertical fungal distribution of AMF spores present in the rhizospheric soil samples of four species of Chenopodiaceae (Allenrolfea patagonica, Atriplex argentina, Heterostachys ritteriana and Suaeda divaricata) at five different depths in two saline of central Argentina. Roots showed medium, low or no colonization (0-50%). Nineteen morphologically distinctive AMF species were recovered. The number of AMF spores ranged between 3 and 1162 per 100 g dry soil, and AMF spore number decreased as depth increased at both sites. The highest spore number was recorded in the upper soil depth (0-10 cm) and in S. divaricata. Depending of the host plant, some AMF species sporulated mainly in the deep soil layers (Glomus magnicaule in Allenrolfea patagonica, Septoglomus aff. constrictum in Atriplex argentina), others mainly in the top layers (G. brohultti in Atriplex argentina and Septoglomus aff. constrictum in Allenrolfea patagonica). Although the low percentages of colonization or lack of it, our results show a moderate diversity of AMF associated to the species of Chenopodiaceae investigated in this study. The taxonomical diversity reveals that AMF are adapted to extreme environmental conditions from saline soils of central Argentina.

In vitro tolerance of Fusarium semitectum and Fusarium solani (anamorphic, Ascomycota) exposed to surface disinfectant commonly used in aquaculture. An in vitro evaluation of the antifungal effect of acetic acid (AcH), buffered acetic acid (AcH+AcNa), potassium iodide (KI) and Iodopovidone (IP); on the growth rate (GR) of Fusarium solani (Mart.) Sacc. 1881 and Fusarium semitectum Berk. & Ravenel, 1875 was performed. Both fungal species were isolated from eggs of the Argentinian silverside Odontesthes bonariensis (Cuvier & Valenciennes, 1835). The studied substances are commonly used in fsh farming as surface disinfectants. The tested concentrations of this substances exhibited antifungal activity for both strains at concentrations higher than their 96h median lethal concentrations (LC50-96h) for the treated eggs; concentrations below the (LC50-96h) exhibited little or no effect.

Se evaluó in vitro el efecto del: acido acético (AcH), ácido acético tamponado (AcH+AcNa), ioduro de potasio (IK) y Iodopovidona (IP) sobre la tasa de crecimiento (TC) de Fusarium solani (Mart.) Sacc. 1881 y Fusarium semitectum Berk. & Ravenel, 1875. Ambas especies fueron aisladas de ovas de Odontesthes bonariensis (Cuvier & Valenciennes, 1835). Las sustancias estudiadas son comúnmente utilizadas en acuicultura como desinfectantes de superfcie. Las concentraciones ensayadas con actividad fungicida para ambas cepas fueron mucho más elevadas que las correspondientes concentraciones letales medias a 96 horas (CL50-96h) para ovas de pejerrey. Concentraciones inferiores a la CL50 - 96h exhibieron un efecto fungistático escaso o nulo.

Arbuscular fungi (Glomeromycota) in the rhizosphere of Atriplex lampa at two saline environments of Córdoba (Argentina): depth infuence on root colonization and the presence of morphospecies. Atriplex lampa is a valuable fodder shrub available for browsing by livestock even during drought periods in the Chaco Phytogeographical Province. Halophytes may beneft from the association with arbuscular mycorrhizal fungi (AMF) through improved tolerance to drought and salt. Ecological studies of AMF are generally restricted to the main rooting zone. However, AMF vertical distribution and seasonal dynamics in natural saline soils of Argentina have been poorly studied. The aim of this work was to explore AMF root colonization, root concentration and to identify AMF morphoespecies in A. lampa rhizosphere in two saline environments (Salinas de Ambargasta and Salinas Grandes) of central Argentina, in fve soil depth levels, during the wet and dry seasons. Despite we did not fnd arbuscules, AMF were found colonizing A. lampa roots in all depth levels. Salinas Grandes showed the highest root colonization value, and showed the highest root concentration, during wet season. The 20 AMF morphospecies identifed in this work belonged to the genera: Acaulospora, Ambispora, Claroideoglomus, Diversispora, Funneliformis, Glomus, Septoglomus and Scutellospora. This is the second record in Argentina of AMF structures in A. lampa roots. Future studies that evaluate mycorrhizal dependency of the plant are necessary to confrm the function of the symbiosis.

Atriplex lampa es un arbusto halófto de la provincia ftogeográfca Chaqueña que constituye un recurso forrajero a lo largo de todo el año. Las plantas halóftas se pueden benefciar al asociarse con los hongos micorrícico arbusculares (HMA), ya que le proveen resistencia contra la salinidad y la sequía. En general, los estudios acerca de los HMA están restringidos a los primeros centímetros del suelo y existe poca información sobre su presencia a mayores profundidades. El objetivo de este trabajo fue estudiar la colonización, la concentración radical e identifcar las morfoespecies de HMA en la rizosfera de A. lampa en dos ambientes salinos del norte de la provincia de Córdoba, durante dos estaciones del año, y en cinco profundidades del suelo. Aunque no se encontraron arbúsculos, A. lampa presentó colonización radical por HMA en todas las profundidades. El mayor valor de colonización micorrícica y de concentración radical se observó en las Salinas Grandes. Se identifcaron 20 morfoespecies de HMA pertenecientes a los géneros: Acaulospora, Ambispora, Claroideoglomus, Diversispora, Funneliformis, Glomus, Septoglomus y Scutellospora. Este es el segundo registro en Argentina de la presencia de HMA en raíces de A. lampa. Es necesario realizar estudios que evalúen la respuesta de A. lampa frente a la inoculación con HMA para confrmar la funcionalidad de la simbiosis.

El hongo entomopatógeno Tolypocladium cylindrosporum ha sido estudiado como un agente de control biológico contra insectos de varios órdenes. Esta especie fue aislada del suelo, así como de insectos de los órdenes Coleoptera, Lepidoptera, Diptera e Hymenoptera. En el presente trabajo hemos analizado la capacidad de una cepa de T. cylindrosporum (LPSC Nº1065) aislada del suelo en Tierra del Fuego, Argentina, para producir enzimas hidrolíticas y determinar la relación de esta actividad con la patogenicidad del hongo para combatir la plaga de los áfidos en diferentes temperaturas (4º, 12º y 24ºC). En los ensayos de patogenicidad, siete días posteriores a la inoculación, se registró mortalidad en los adultos del áfido Ropalosiphum padi a diferentes temperaturas y también se demostró una amplia capacidad de crecer en varios medios de cultivos complementados con diferentes fuentes de carbono bajo las tres temperaturas de incubación ensayadas. Debido a su origen y a la tolerancia que tiene a bajas temperaturas esta cepa, presenta un gran potencial para su uso como agente de control biológico para las plagas de insectos de ambientes fríos y templados.

Tolypocladium cylindrosporum is an entomopathogenic fungi that has been studied as a biological control agent against insects of several orders. The fungus has been isolated from the soil as well as from insects of the orders Coleoptera, Lepidoptera, Diptera and Hymenoptera. In this study, we analyzed the ability of a strain of T. cylindrosporum, isolated from soil samples taken in Tierra del Fuego, Argentina, to produce hydrolytic enzymes, and to study the relationship of those activities to the fungus pathogenicity against pest aphids. We have made the traditional and molecular characterization of this strain of T. cylindrosporum. The expression of hydrolase activity in the fungal strain was estimated at three incubation temperatures (4ºC, 12ºC and 24ºC), on different agar media supplemented with the following specific substrates: chitin azure, Tween ® 20, casein, and urea for chitinase, lipase, protease, and urease activity, respectively. The hydrolytic-enzyme activity was estimated qualitatively according to the presence of a halo of clarification through hydrolase action, besides was expressed semi-quantitatively as the ratio between the hydrolytic-halo and colony diameters. The pathogenicity of the fungus was tested on adults of the aphid Rhopalosiphum padi at three temperatures of incubation (4ºC, 12ºC and 24ºC). The suspension was adjusted to a concentration of 1x10 7 conidia/ml. In pathogenicity assays at seven days post-inoculation, the fungus caused the mortality of adults of Ropalosiphum padi at different temperatures also showed a broad ability to grow on several agar-culture media, supplemented with different carbon sources at the three incubation temperatures tested. Although, the growth was greater with higher incubation temperatures (with maximum levels at 24°C), the fungus reached similar colony diameters after 15 days of incubation on the medium supplemented with Tween® 20 at the lower two incubation temperatures of 4°C or 12°C. In accordance with the results on colony diameters, the fungus revealed an ability to degrade casein, chitin derivatives, Tween® 20, and urea as evidenced by the appearance of a halo around the fungal colony. Because of its origin and temperature tolerance, this Argentine strain has great potential for use as a biocontrol agent for insect pest control in cold and temperate environments. Rev. Biol. Trop. 60 (2): 833-841. Epub 2012 June 01.