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This study compares the culturable fungal endophytic community inhabiting leaves of Epichloë-infected (E+) and Epichloë-free (E-) plants of Poa bonariensis. Plants were collected from a wild population (dioecious species) where E+ and E- plants co-exist. Fungal endophytes were isolated and then morphology and ribosomal DNA internal transcribed spacer sequences were used for the identification of isolates. In total 24 different taxa of non-Epichloë (NE) endophytes were identified. No significant differences were found in richness and diversity indexes of NE-endophytes between E+ and E- plants, or between pistillate (P) and staminate (S) plants. When we analyzed these effects based on the count of the most abundant genera, Alternaria and Stemphylium infection frequencies decreased in S plants, while in E+ plants, this tendency was observed for Alternaria. Our results suggest that Epichloë and the sex of the host plant may modulate some of the dominant foliar endophytic fungal taxa. Fil: Mc Cargo, Patricia Débora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Iannone, Leopoldo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Soria, Marcelo. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina

A field experiment was performed to study the effect of Epichloë endophytes of the wild forage grass Bromus auleticus on mycorrhizal colonization, seedling emergence and growth parameters in three heterospecific grasses of agronomic interest. Plots with B. auleticus associated with Epichloë (E+) and non-associated (E-) plants were established and 3 y later, seeds of Lolium multiflorum (E+ or E-), Schedonorus arundinaceus (E+ or E-) and Bromus catharticus (not establishing associations with Epichloë) were sown as B. auleticus neighbors. B. auleticus E+ plants induced a significant increase in mycorrhizal colonization of the neighbor grasses, even higher in the E- neighbor plants (L. multiflorum and S. arundinaceus), in comparison to B. auleticus E- neighbors. Seedling emergence, root length, leaves number or shoot dry weight were not affected. This is the first approach to studying these triple interactions (endophyte-grass-mycorrhiza) involving wild and forage grasses in the field. Our results show that the effect of Epichloë extends further than its own host and suggest an interaction among endophytes of heterospecific neighbors at the rhizosphere level.Keywords arbuscular mycorrhizal fungi, Bromus auleticus, Lolium multiflorum, multiple mutualistic symbiosis, root exudates, Schedonorus arundinaceus Fil: Vignale, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Iannone, Leopoldo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina

Neotyphodium endophytes and arbuscular mycorrhizal (AM) fungi are common constituents of natural grasslands. The plant?endophyte symbiosis can introduce changes in soil conditions that affect the density and activity of different functional groups of soil organisms. A few experiments have reported that leaf endophytes can reduce mycorrhizal sporulation and colonization of host roots in agronomic hosts, contrasting with the studies we have conducted in native grasses from Argentina. In the present work we performed in vitro assays to evaluate the effect of root and endophyte exudates on the pre-infective state of mycorrhizal fungi (Gigaspora margarita and G. rosea). Plant roots of Bromus setifolius, from populations of Patagonia and four strains of Neotyphodium were used to obtain the exudates. Root exudates of infected plants, at a high concentration, significantly increased AMF hyphal branches and length. The effect of endophyte exudates on AMF mycelia lenght, varied depending on strain and the concentration used, suggesting a differential interaction between endophyte and AMF species. AMF hyphal branches were increased by fungal exudates in both mycorrhizal species. This study reports the direct and positive effect of Neotyphodium endophytes on AMF pre-infective state, supporting previous information on native grasses. Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Iannone, Leopoldo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Godeas, Alicia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina Fil: Scervino, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina

Fungal endophytes inhabit healthy tissues of all terrestrial taxa studied to date; however, fungi associated with woody tissue have been frequently overlooked. Here, we examined endophytes associated with healthy living stems of tree species exotic to Argentina (Broussonetia papyrifera, Celtis occidentalis and Ligustrum lucidum) in a natural reserve. To achieve this objective, fungi were induced to develop within the wood by drying sections of branches. For comparison purposes, a study of the organisms present on superficial and inner bark was carried out. Fifty-seven strains belonging to 12 different taxa, dominated by the anamorphic states of ascomycetes, were obtained from the 180 cultured chips. Coprinellus micaceus, Lecythophora hoffmannii and Rhizopus microsporus are cited for the first time as endophytes. Only two taxa appeared on more than one tree species. Assemblages of fungi obtained from each tree species were different and the fungal endophytes isolated were very different from those previously recorded for leaves of the same hosts in the same area. Thus, it is probable that the endophytes exhibit host- and tissue-specificity. Considering three main factors: 1. the invasive nature of two of the selected hosts, 2. the evaluation of woody tissue and 3. the taxonomic identity of the fungal isolations, hypotheses concerning ecological implications are here discussed. In this sense, Broussonetia papyrifera and Ligustrum lucidum could be considered as sources of potential inoculum for native plants, especially in protected areas, and the high diversity of fungal species living within the tissues of the hosts studied suggests their potential as important fungal reservoirs to be taken into account in conservation issues.

An ecological investigation of foliar endophytic fungal communities on Broussonetia papyrifera, Celtis occidentalis and Ligustrum lucidum was carried out in the natural reserve Dr. Carlos Spegazzini, Buenos Aires, Argentina. The study yielded 21 taxa. Alternaria and Xylaria were the most abundant ones and both were isolated from the three hosts. Phomopsis ligustri-vulgaris, Pycnidiella resinae, Scytalidium acidophilum, Thermomyces lanuginosus and the genus Haplotrichum are cited for the first time as endophytic microorganisms, while P. resinae, Scytalidium aff. acidophilum and T. lanuginosus are cited for the first time in Argentina. A new species, Haplotrichum minutissimum, is described. Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Carmaran, Cecilia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina

Background and aims: Plants often establish multiple simultaneous symbiotic associations with different micro-organisms; however, the way in which each symbiont affects the other symbionts and the effects of these multiple interactions on plant performance are not well understood. The aim of this study was to evaluate how two different asexual Epichloë species modulate the establishment of arbuscular mycorrhizal fungi (AMF) in a wild forage grass under different soil fertilization levels. Methods: We performed a completely randomized 12-month-long field experiment to evaluate the effect of two B. auleticus-endophyte ecotypes and two soil fertilization levels on the colonization of AMF, in seedlings and adult plants. Plant biomass and reproductive tillers production were also measured. Results: The symbiosis, measured as the total extent of AM fungal colonization and frequency of arbuscules was significantly higher in Epichloë-infected plants and was not affected by fertilization either in seedlings or in adult plants. Plant biomass was increased by fertilization but no differences were observed due to the endophytic status. However, E+ plants produced more panicles than their E− counterparts. Conclusions: Our findings strongly support the hypothesis of positive association between Epichloë endophytes and AMF in wild grasses, making this model important for agronomic improvement. Fil: Vignale, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Iannone, Leopoldo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Pinget, Albertina Daniela. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Concepción del Uruguay; Argentina Fil: De Battista, José P.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Concepción del Uruguay; Argentina Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina

Fungal endophytes comprise a highly diverse group of particular interest for their relevant implications to the ecosystems they inhabit. The objective of this study was to infer the phylogenetic affinity between strains of Peroneutypa scoparia exhibiting different lifestyles to elucidate possible shifts in ecological roles. Specimens and living cultures used in the present study were obtained from decaying wood and from live stem tissues of the invasive host species Broussonetia papyrifera. The similarity between the fungal strains was studied through molecular analyses. The results showed a close phylogenetic link and high genetic similarity between endophytic and saprotrophic strains. The main findings suggest that P. scoparia has primary access to the substrate as an endophyte and then, this organism may change its use of the available resources presenting a saprotrophic growth. These results provide valuable information about the roles that diatrypaceous fungi play as endophytes or as decaying wood inhabitants and contributes to evaluate the ecological significance of this group. Fil: de Errasti, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botanica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botanica; Argentina Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botanica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botanica; Argentina Fil: Carmaran, Cecilia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botanica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botanica; Argentina

The interaction between mycorrhiza and leaf endophytes (Neotyphodium sp.) was studied in three Poa bonariensis populations, a native grass, differing significantly in endophyte infection. The association between endophytes and mycorrhizal fungi colonisation was assessed by analysing plant roots collected from the field. We found that roots from endophyte-infected populations showed a significantly higher frequency of colonisation by mycorrhizal fungi and that soil parameters were not related to endophyte infection or mycorrhiza colonization. In addition, we did not observe significant differences in the number of AM propagules in soils of the three populations sites. We also report the simultaneous development of Paris-type and Arum-type mycorrhiza morphology within the same root systems of P. bonariensis. The co-occurrence of both colonisation types in one and the same root system found in the three populations, which differed in Neotyphodium infection, suggests that foliar endophytes do not determine AM morphology. The percentage of root length colonised by different types of fungal structures (coils, arbuscules, longitudinal hyphae and vesicles) showed significant and positive differences in arbuscular frequency associated with endophyte infection, whereas the much smaller amounts of vesicles and hyphal coils did not differ significantly. Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Iannone, Leopoldo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Godeas, Alicia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina Fil: Cabral, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina

Vegetative compatibility (VC) of Aspergillus flavus isolates from peanut seed was studied to evaluate preliminary diversity and its association with mycotoxin production and sclerotia production and number. A. parasiticus isolates also were included as a comparative group. Isolates were divided into five categories based on mycotoxin production combination. Five of the A. flavus isolates were considered atypical because they simultaneously produced aflatoxins B, G, and cyclopiazonic acid (CPA). Vegetative compatibility groups (VCGs) were determined through complementation tests between nitrate-nonutilizing mutants. Sclerotia diameters and the number of sclerotia produced per square centimeter were determined for each isolate. Out of 32 isolates of A. flavus, 25 combined in 13 VCGs, whereas the remaining could not be assigned to any particular group. Each VCG included isolates of the same mycotoxin category, with only one exception. Also, all isolates within the same VCG were characterized by their ability to produce or not produce sclerotia. Isolates between VCGs showed significant differences in number of sclerotia per square centimeter, but differences in sclerotia size were not evident. Atypical isolates simultaneously producing aflatoxins B, G, and CPA formed a single and exclusive VCG. Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Cabral, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina