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Alternaria is one of the main fungal contaminants of cereal grains worldwide with the potential to produce mycotoxins hazardous to human and animal health. Many studies have been carried out to characterize Alternaria sp.-grp. using traditional morphology or polyphasic approach, but a good correlation between morphological sp.-grp., molecular, and chemotaxonomic groups has not always been achieved. For this reason, this study aimed to investigate the usefulness of a cheaper alternative tool, SRAP markers, in identifying Alternaria sp.-grps. obtained from Argentinean barley grains and to compare it with preliminary characterization using morphological traits, phylogeny, and metabolite profiles. Fifty-three Alternaria isolates from barley grains of the main producing regions of Argentina were analyzed with four combinations of SRAP markers. The UPGMA dendrogram, based on the Simple Matching similarity coefficient, revealed three distinct groups. SRAP markers allowed the separation of Alternaria from Infectoriae sections in agreement with the results of a polyphasic approach previously made. Besides, isolates of A. arborescens sp.-grp. were clustered in a separate group from isolates of A. tenuissima and A. alternata sp.-grp., which were grouped in the same cluster. SRAP markers are a recommended tool for classifying Alternaria isolates because of its simplicity, reliability, and cost-effectiveness compared to other molecular markers., Competing Interests: Declaration of competing interest There are no interests to declare to the work titled “SRAP markers as an alternative tool for Alternaria classification”, (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Fusarium Head Blight (FHB) is a devastating disease that affects the grain yield and quality of essential crops such as wheat. In the last years, some Fusarium species have acquired particular importance as Fusarium poae. However, studies to evaluate F. poae-wheat interaction are still scarce. The interaction between F. poae and two bread wheat cultivars with different resistance levels against FHB was evaluated. Moreover, the application of methyl-jasmonate (MeJA) was evaluated as a possible tool to reduce the fungal presence. Our results showed that the MeJA treatment is isolate-dependent, reducing F. poae fungal growth. A decrease in fungal biomass was observed in the susceptible cultivar after MeJA application; however, no differences between inoculated and inoculated-MeJA treatments were observed in the resistant cultivar. Finally, the F. poae inoculation induces the expression of PR1-1 and PDF 1.2, being early in the resistant cultivar compared to the susceptible ones. The application of MeJA combined with the F. poae inoculation increased PR1-1 and PDF1.2 expressions in resistant cultivars. To our knowledge, this is the first study that evaluates the interaction between F. poae and wheat and the MeJA treatment as a possible management strategy against this important pathogen., Competing Interests: Declaration of competing interest None., (Copyright © 2022 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

Fusarium graminearum is ranked among the five most destructive fungal pathogens that affect agroecosystems. It causes floral diseases in small grain cereals including wheat, barley, and oats, as well as maize and rice. We conducted a systematic review of peer-reviewed studies reporting species within the F. graminearum species complex (FGSC) and created two main data tables. The first contained summarized data from the articles including bibliographic, geographic, methodological (ID methods), host of origin and species, while the second data table contains information about the described strains such as publication, isolate code(s), host/substrate, year of isolation, geographical coordinates, species and trichothecene genotype. Analyses of the bibliographic data obtained from 123 publications from 2000 to 2021 by 498 unique authors and published in 40 journals are summarized. We describe the frequency of species and chemotypes for 16,274 strains for which geographical information was available, either provided as raw data or extracted from the publications, and sampled across six continents and 32 countries. The database and interactive interface are publicly available, allowing for searches, summarization, and mapping of strains according to several criteria including article, country, host, species and trichothecene genotype. The database will be updated as new articles are published and should be useful for guiding future surveys and exploring factors associated with species distribution such as climate and land use. Authors are encouraged to submit data at the strain level to the database, which is accessible at https://fgsc.netlify.app.

Alternaria is one of the main fungal genera affecting the quality of barley grains. In this study, a polyphasic approach was carried out to characterise the Alternaria population infecting different cultivars of barley grains from the major producing regions of Argentina in the 2014 and 2015 seasons. Its relationship with Fusarium and correlations between predominant species, barley cultivars, and climatic conditions in the growing regions were evaluated. Alternaria incidence exceeded that of Fusarium in all the barley samples and was higher in the drier season (21% in 2014 and 42% in 2015 vs. 6% and 4%, respectively). The main Alternaria species-groups identified were present in both growing seasons in similar frequencies (A. tenuissima sp.-grp., 83.4% in 2014 and 81.7% in 2015; A. infectoria sp.-grp., 11.7% in 2014 and 11.3% in 2015). The dominant Alternaria species-group isolated and identified based on morphological characteristics, DNA sequencing, and metabolite profile was A. tenuissima (72.9%), followed by A. infectoria (14.6%). An association between their frequency and field temperature was observed; A. tenuissima sp.-grp. was more frequent in northern localities, where higher temperatures were registered, while the opposite was observed for A. infectoria sp.-grp. A smaller percentage of A. arborescens sp.-grp. (5%), A. alternata sp.-grp. (3.9%) and A. vaccinii (1.4%) were also identified. Both secondary metabolite profiles and phylogenetic analysis were useful to distinguish isolates from Alternaria section Alternaria and section Infectoriae. Regarding metabolite profiles, alternariol was the most frequent compound produced by isolates of the section Alternaria. Infectopyrones and novae-zelandins were produced by most of the isolates from section Infectoriae. The barley cultivars analysed in this study did not show a particular susceptibility regarding the Alternaria population composition, except for Andreia, which presented the highest frequency of contamination with A. tenuissima sp.-grp. The rest of the cultivars, when grown in different regions, showed different proportion of the Alternaria sp.-grps., suggesting that other factors were determinant in their distribution. The results obtained in the present study will be a valuable tool for health authorities to assess the need for regulations on Alternaria mycotoxins, given the high incidence of Alternaria spp. in barley and the diversity of metabolites that might contaminate the grains., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Barley is one of the most sown crops in the world, with multiple uses such as human consumption, animal feed and for the malting industry. This crop is affected by different diseases, such as Fusarium Head Blight (FHB), that causes losses in yield and quality. In the last years F. graminearum and F. poae were two of the most frequently isolated species in barley grains, so the aim of this study was to evaluate the interaction between these Fusarium species and the effects on disease parameters, grain quality and mycotoxin contamination on five barley genotypes under field conditions., Results: Statistical differences between Fusarium treatments for some parameters depending mainly on the year/genotype were found. The results showed that the germination process was affected by both Fusarium species. As to grain quality and the different hordein fractions, it was observed that F. graminearum affects preferentially D and C-hordeins. Different concentrations of nivalenol, deoxynivalenol and their acetylated derivatives (3-acetyl deoxynivalenol (3-ADON), 15-acetyl deoxynivalenol (15-ADON)) were detected., Conclusions: In the present work, no evidence of synergism between F. graminearum and F. poae were found regarding disease parameters and mycotoxin contamination. However, at least in the years with favorable climatic conditions to FHB development and depending on the barley genotype, a continuous monitoring is deemed necessary to prevent the negative impact on protein composition and germinative parameters © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: Barley (Hordeum vulgare L.) is one of the most important cereals worldwide, and its quality is affected by fungal contamination such as species of the genus Alternaria. No information is available about the occurrence of Alternaria mycotoxins in Argentinean barley grains, which is of concern, because they can be transferred into malt and beer. The aim of this study was to analyze the occurrence of alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TeA) in malting barley grains from the main producing region of Argentina during the 2014 and 2015 growing seasons., Results: The most frequent mycotoxin was AOH (64%), which was detected at higher levels (712 μg kg -1 ) compared with other studies, followed by TeA (37%, 1522 μg kg -1 ), while AME was present in five samples in the 2015 growing season only, with a mean of 4876 μg kg -1 . A similar frequency of mycotoxin occurrence was observed in both years (80.8 vs 85.3%), but more diverse contamination was found in 2015, which was characterized by lower accumulated precipitation. Nevertheless, AOH was more frequently found in 2014 than in 2015 (80.8 and 47.1% respectively). A negative correlation between AOH concentration and temperature was observed. The susceptibility of different barley varieties to mycotoxin accumulation varied with the mycotoxin, geographical location and meteorological conditions., Conclusion: The results obtained in the present work represent a tool for risk assessment of exposition to these mycotoxins and could be used by food safety authorities to determine the need for their regulation. Furthermore, the establishment of a hazard analysis and critical control point (HACCP) system to minimize fungal and mycotoxin contamination in barley from farm to processing could be apply to ensure food safety. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Background: Wheat is the most important winter crop in the world, being affected by the presence of fungal, mainly those belonging to the Fusarium genus. Fusarium head blight (FHB) is a serious disease that causes important economic damage and quantitative/qualitative losses, with Fusarium graminearum and Fusarium poae being two of the most isolated species worldwide. The present study aimed to evaluate the interaction between F. graminearum and F. poae and the effects on disease parameters, grain quality and mycotoxin contamination on five wheat genotypes under field conditions during three growing seasons., Results: Statistical differences between Fusarium treatments were found for disease parameters, grain quality and mycotoxin contamination during the 2014/2015 growing season. High values of incidence (58.00 ± 8.00%), severity (6.28 ± 1.51%) and FHB index (4.72 ± 1.35) were observed for F. graminearum + F. poae treatment. Regarding grain quality, the results showed that the degradation of different protein fractions depends on each Fusarium species: glutenins were degraded preferably by F. graminearum (-70.82%), gliadins were degraded preferably by F. poae (-29.42%), whereas both protein fractions were degraded when both Fusarium species were present (-60.91% and -16.51%, respectively). Significant differences were observed for mycotoxin contamination between genotypes, with Proteo being the most affected (DON = 12.01 ± 3.67 μg g -1 ). In addition, we report that 3-ADON predominated over 15-ADON in the three seasons evaluated., Conclusion: Variations in plant-pathogen interaction (Fusarium-wheat pathosystem) should be considered at least in years with favorable climatic conditions for FHB development, as a result of the potential impact of this disease on grain quality and mycotoxin contamination. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

In this work, we present a novel biostimulant for sustainable crop disease management, PSP1, based on the plant defense-elicitor AsES, an extracellular protease produced by the strawberry fungal pathogen Acremonium strictum . Fungal fermentation conditions and downstream processing were determined to maximize extracellular protein production, product stability and a high plant defense-eliciting activity, as monitored by anthracnose resistance in supernatant-treated strawberry plants subsequently infected with a virulent strain of Colletotrichum acutatum . Fermentation batches were shown to reduce anthracnose development by 30-60% as compared to infected non-treated plants. Product formulation was shown to be stable for 6 months when stored at temperatures up to 45°C and toxicological tests showed that PSP1 was harmless to beneficial organisms and non-toxic to mammalian species at concentrations 50 times higher than those used in plant experiments. Furthermore, disease protection studies using dilutions of PSP1 indicated that there is a minimum threshold protease activity needed to induce pathogen defense in strawberry and that this induction effect is dose-independent. A significant characteristic of PSP1 is its broad-range protection against different diseases in various crop species. In soybean, PSP1 reduced the symptomatology by 70% of Corynespora cassiicola , etiological agent of the target spot. This protection effect was similar to the commercial inducer BION 500 WG based on BTH, and both products were shown to induce an oxidative burst and up-regulated PR1 -gene expression in soybean. Furthermore, a double PSP1-treatment on greenhouse-grown sugarcane plants provided protection against bacterial red stripe disease caused by Acidovorax avenae and a double foliar application of PSP1 on field-grown wheat plants significantly increased resistance against Fusarium graminearum , causal agent of head blight disease, manifested mainly in an increased seed germination rate. In summary, these disease protection studies demonstrated an effective control against both bacterial and fungal pathogens in both monocot and dicot crop species, which together with its low production cost, effectiveness at low concentrations, long shelf-life, tolerance to high temperatures, harmlessness to non-target organisms and simple handling and application, make PSP1 a very promising candidate for effective and sustainable disease management in many crop species.

Fungi of yield soils represent a significant portion of the microbial biomass and reflect sensitivity to changes in the ecosystem. Our hypothesis was that crops included in cropping regimes under the zero tillage system modify the structure of the soil fungi community. Conventional and molecular techniques provide complementary information for the analysis of diversity of fungal species and successful information to accept our hypothesis. The composition of the fungal community varied according to different crops included in the cropping regimes. However, we detected other factors as sources of variation among them, season and sampling depth. The mixed cropping regimes including perennial pastures and one crop per year promote fungal diversity and species with potential benefit to soil and crop. The winter season and 0-5 cm depth gave the largest evenness and fungal diversity. Trichoderma aureoviride and Rhizopus stolonifer could be used for monitoring changes in soil under zero tillage.

Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) is one of the major lepidopteran pests defoliating soybeans (Glycine max Merrill) in Argentina. The combined use of chemical insecticides and entomopathogenic fungi is a promising pest-control option to minimize adverse chemical effects. In this work, we evaluated the interactions between five insecticides-two being considered biorational-and five fungal entomopathogenic strains under laboratory conditions in order to determine the possible usefulness of combinations of these agents against R. nu. The insecticides were tested for compatibility at four doses by in vitro bioassay and for the lethality of R. nu by inoculations at three doses. Fungal strains were applied at 1×10 8 , 1×10 6 , and 1×10 4 conidia/ml. The combinations of those insecticides with Beauveria bassiana (LPSc 1067, LPSc 1082, LPSc 1098), Metarhizium anisopliae (LPSc 907), and Metarhizium robertsii (LPSc 963) caused higher R. nu-larval mortalities than any of the individual agents alone. We observed significant differences in the in vitro conidial viability, vegetative growth, and conidia production of the five strains of entomopathogenic fungi exposed to different doses of the chemical insecticides. The combination gamma-cyhalothrin-LPSc-1067 caused the highest percent mortality of R. nu larvae, with synergism occurring between the two agents at 50% and 25% of the maximum field doses., (Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Two of the most common species of toxin-producing Fusarium contaminating small cereal grains are Fusarium graminearum and F. poae ; with both elaborating diverse toxins, especially deoxynivalenol (DON) and nivalenol (NIV), respectively. The objective of our work during the 2012-2014 growing seasons was to screen crops for the most commonly isolated Fusarium species and to quantify DON and NIV toxins in natural malting-barley samples from different producing areas of Argentina. We identified 1180 Fusarium isolates in the 119 samples analyzed, with 51.2% being F. graminearum , 26.2% F. poae and 22.6% other species. We found high concentrations of mycotoxins, at maximum values of 12 μg/g of DON and 7.71 μg/g of NIV. Of the samples, 23% exhibited DON at an average of 2.36 μg/g, with 44% exceeding the maximum limits (average of 5.24 μg/g); 29% contained NIV at an average of 2.36 μg/g; 7% contained both DON and NIV; and 55% were without DON or NIV. Finally, we report the mycotoxin contamination of the grain samples produced by F. graminearum and F. poae , those being the most frequent Fusarium species present. We identified the main Fusarium species affecting natural malting-barley grains in Argentina and documented the presence of many samples with elevated concentrations of DON and NIV. To our knowledge, the investigation reported here was the first to quantify the contamination by Fusarium and its toxins in natural samples of malting barley in Argentina., Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Fusarium poae has been considered as a minor species among those that cause the FHB disease but in recent years several researchers have documented a high frequency of occurrence in several crops. We evaluated the ability of F. poae to produce symptoms in A. thaliana leaves. Moreover, we analyzed the defense of A. thaliana against F. poae using SA, JA, and ET mutants and we monitored the expression level of genes involved in the main signaling pathways related to plant defense. Symptoms were observed in the inoculated leaves demonstrating the ability of F. poae to infect A. thaliana leaves. Moreover, the npr1-1 mutants presented low symptoms compared to Col-0, etr2-1, and coi1-1 and that the coi1-1 mutant was the most susceptible genotypes followed by etr2-1 genotypes. The RT-PCR revealed that PDF1.2, CHI/PR3, and ERF1, three important JA-ET responsive genes and NPR1 and PR1, which are regulated by SA signaling, were expressed upon F. poae inoculation. Our results suggest that JA and ET could play a key role in Arabidopsis leaves defense against F. poae representing the first evaluation of the response of the main A. thaliana phytohormones involved in plant defense in the presence of F. poae., (Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

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 1cm(2) 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., (Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience.

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., (Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Background: Several fungal species represent a potential risk to embryos of Odontesthes bonariensis (Cuvier and Valenciennes, 1835), a euryhaline freshwater fish that lives in the Pampean inland waters and has potential economic relevance., Aims: To identify two fungi isolated from O. bonariensis eggs exposed to saline conditions and to characterize their pathogenicity and tolerance to sodium chloride solutions., Methods: The isolates were identified by morphological features, and a preliminar phylogenetic analysis using sequences of translation elongation factor 1-alpha (EF-1α) and calmodulin (CAM) was performed. Koch's postulates were tested to identify the causative agent of fungal infection. The influence of NaCl on the fungal growth was evaluated in in vitro assays., Results: The isolates LPSC 1001 and 1002 were identified as representatives of the genus Fusarium, and belonging to the Fusarium incarnatum-Fusarium equiseti species complex (FIESC) and the Fusarium solani species complex (FSSC), respectively. Histological observations on eggs exposed in vitro to both isolates in infectivity assays confirmed the ability of the fungal isolates to penetrate to egg's chorionic membrane, leading to the death of embryos. Increasing NaCl concentration in the culture medium reduced the growth of the isolates LPSC 1001 and 1002, being completely inhibited at 160 and 120g/l NaCl respectively., Conclusions: The isolates LPSC 1001 (FIESC) and 1002 (FSSC) were identified as fungal pathogens to O. bonariensis eggs. The use of NaCl solutions as antifungal treatment was not effective to control the infection with these strains., (Copyright © 2014 Asociación Española de Micología. Published by Elsevier Espana. All rights reserved.)

Fusarium poae is a relatively weak pathogen with increasing importance in cereal grains, principally due to its capacity to produce several mycotoxins. In this study, we evaluated the pathogenicity and toxin accumulation of individual F. poae isolates on wheat and barley under natural conditions for 3 years. Analysis of variance demonstrated significant differences for year-genotype, year-isolate, genotype-isolate, and year-genotype-isolate interactions for both incidence and disease severity. Based on contrast analysis, 'Apogee' was more susceptible than the other wheat genotypes, wheat genotypes were more susceptible than barley genotypes, durum wheat genotypes were more susceptible than bread wheat genotypes, and barley genotype 'Scarlett' had greater symptom development per spike than the other barley genotypes. Neither HT-2 nor T-2 toxins were detected in the grain samples. However, high levels of nivalenol were found in both wheat and barley samples. The increased reported isolation of F. poae from wheat and barley and the high capacity of this fungus to produce nivalenol underlie the need for more studies on F. poae-host interactions, especially for barley.

Fusarium graminearum is one of the most important pathogens isolated from small cereal grains with Fusarium Head Blight symptoms. The presence of this fungus is often linked to the occurrence of several mycotoxins in barley and wheat. The aim of our study was to characterize trichothecene genotypes and production profiles of F. graminearum sensu stricto isolates obtained from barley grains in Argentina. A total of 110 F. graminearum s.s. isolates were analyzed by PCR assays to predict deoxynivalenol (DON), 15-acetyldeoxynivalenol (15-ADON), 3-acetyldeoxynivalenol (3-ADON) and nivalenol (NIV) production, and all isolates were found to belong to the same molecular 15-ADON genotype. Trichothecene production in autoclaved rice was analyzed by using gas chromatography (GC) and confirmed by GC-MS. Of the 110 isolates, 95% were able to produce DON, 71% produced 15-ADON, 63% 3-ADON and 52% NIV. With the exception of a single isolate, all isolates that produced NIV, also produced DON. However, the NIV production was very low, ranging from 0.13 to 0.30 μg/g. Six different production profiles of DON and its acetyl-derivatives were detected, the predominant being simultaneous production of DON, 3-ADON and 15-ADON, followed by DON production, and DON and 15-ADON co-production. This work is the first attempt to characterize the trichothecene genotypes and production profiles of F. graminearum s.s. isolates from Argentinean barley., (Copyright © 2014 Elsevier B.V. All rights reserved.)

One of the most important diseases in cereal crops is Fusarium head blight, being Fusarium graminearum the main etiological agent. This fungus has the ability to produce a wide spectrum and quantity of toxins, especially deoxynivalenol (DON). During the last crop season (2012-2013) the climatic conditions favored Fusarium colonization. The objective of this work was to determine the presence of this fungus as well as the DON content in 50 wheat grain samples. Our results showed that 80% of the samples were contaminated with Fusarium graminearum. Twenty four percent (24%) of the samples contained ≥ 1μg/g DON, 26% ranged from 0,5 and 0,99μg/g, and the remaining 50% had values lower than 0,5μg/g. Correlation was found between the presence of Fusarium graminearum and DON. It is necessary to establish DON limit values in wheat grains for human consumption., (Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.)

Some producers of dry fermented sausages use fungal starter cultures with the aim to achieve a desirable surface appearance and avoid the growth of mycotoxigenic fungi. These commercial cultures are mainly composed of Penicillium nalgiovense biotype 6. In contrast, in the case of producers who do not use starters, sausages are spontaneously colonized by the house mycobiota, which generally consists of heterogeneous molds corresponding to different genera and species. In this work, the surface mycobiota of dry fermented sausages produced in Colonia Caroya (Córdoba, Argentina) was determined in both summer and winter seasons. All the sausages sampled had been made without the use of surface fungal starters. In the 57 sausages analyzed in the two winter seasons studied (2010 and 2012), we found a total of 95 isolates of filamentous fungi belonging to six genera (Penicillium, Aspergillus, Mucor, Cladosporium, Scopulariopsis and Eurotium) and ten fungal species, whereas in the 36 sausages analyzed in the two summer seasons studied (2011 and 2012), we found 89 isolates belonging to five genera (Penicillium, Aspergillus, Mucor, Cladosporium and Geotrichum) and ten fungal species. Although 16 different species were found in both winter and summer seasons, only 2 of them predominated completely. P. nalgiovense was found in almost 100% of the sausages analyzed, where biotype 4 was the most frequent. This species gives a whitish gray coloration to the sausages. Considering that the factories sampled do not use fungal starter cultures, this predominance is very interesting since mycotoxin production by this fungus has not been reported. Aspergillus ochraceus was isolated with a frequency of 80-90% in the summer seasons, but in none of the winter samples. The presence of this fungus in sausages produced in the summer was attributed to the high environmental temperatures and the uncontrolled temperature in the ripening rooms during the night. In all cases, A. ochraceus was responsible for the undesirable yellowish gold color of the casing. This fungus thus causes significant economic losses to the producers of Colonia Caroya during the months of high temperatures., (Copyright © 2013 Elsevier B.V. All rights reserved.)

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 (4 degreeC, 12 degreeC and 24 degreeC), 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 (4 degree C, 12 degree C and 24 degree C). 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 degreeC), 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 degreeC or 12 degreeC. 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.

Barley (Hordeum vulgare L.), one of the most widely grown winter cereal crops in Argentina, is primarily grown for use as malted barley for the beer industry. In December 2010, a survey of fungi was conducted in a barley (cv. Shakira) seed lot in a field located in Tres Arroyos, Buenos Aires, Argentina. A sample of 400 seeds was surface sterilized (70% EtOH for 2 min and 5% NaClO for 2 min), rinsed twice in sterilized distilled water, plated on potato dextrose agar (PDA), and incubated at 24 ± 2°C in a 12-h dark/light cycle. One isolate that was morphologically similar to Fusarium graminearum was observed after 6 days of incubation. The isolate was transferred onto PDA and carnation leaf agar (CLA) substrates and grown with the same conditions as described above. On PDA, the isolate produced abundant, white-to-yellow-to-red, aerial mycelium and formed red pigments in the medium. On CLA, macroconidia were abundant, relatively slender and almost straight to moderately curved, and commonly five to six septate. Microconidia were not observed. Chlamydospores were observed after 3 weeks. The fungus was initially identified as F. graminearum on the basis of morphology of the asexual stage (1). Pathogenicity was conducted using a hand sprayer to inoculate five barley (cv. Shakira) heads in potted plants with a 5-ml asexual spore suspension (1 × 10 4 conidia per ml). Two heads were sprayed with sterile distilled water as a control. Plants were covered with polyethylene bags and incubated for 3 days in a growth chamber under a 12-h day/dark cycle at 22 ± 2°C. Plants were unbagged and moved into a greenhouse. Noninoculated spikelets were asymptomatic and inoculated spikelets showed discoloration or a tan-to-dark brown necrosis. The fungus was reisolated from symptomatic kernels. DNA of the isolate was extracted (3) and the isolate was identified to species by sequencing the reductase (RED), trichothecene 3-O-acetyltransferase (tri101), and translation elongation factor (TEF) regions (4). The sequences were compared with those in GenBank. The RED sequence (Accession No. JQ350697) showed 100% similarity, the tri101 (Accession No. JQ350698) showed 99% similarity, and the TEF (Accession No. JQ350699) showed 100% similarity with several F. pseudograminearum sequences. Additionally, the isolate was tested for the potential to produce deoxinyvalenol (DON) using a PCR approach that allows identification of two acetylated forms of DON: 15-acetyl-DON (15-ADON) and 3-ADON (2). A PCR product indicative of a 3-ADON genotype was obtained. To our knowledge, this is the first report of F. pseudograminerum associated with barley kernels in Argentina. Considering its potential to cause head blight and product mycotoxins, a large-scale survey of F. pseudograminearum on barley crops in Argentina is underway. A voucher culture (No. 1154) has been deposited in the Culture Collection of the La Plata Spegazzini Institute. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Oxford, UK. 2006. (2) A. Quarta et al. Food Addit. Contam. 22:309, 2005. (3) S. A. Stenglein and P. A. Balatti. Physiol. Mol. Plant Pathol. 68:158, 2006. (4) T. J. Ward et al. Fungal Genet. Biol. 45:473, 2008.

Wheat (Triticum aestivum L.), the most widely grown winter cereal crop in Argentina, is grown on 5 million ha. Fusarium species affect yield and grain quality because of mycotoxins. In December 2009, a screen of fungal species in wheat seeds from a field in Azul, Buenos Aires, Argentina was conducted. Four hundred seeds were surface sterilized by dipping successively into 70% ethanol for 2 min, 5% sodium hypochlorite for 2 min, and finally rinsing twice in fresh sterilized distilled water. The seeds were plated on potato dextrose agar (PDA), pH 6, and incubated at 24 ± 2°C with exposure to 12-h alternate cycles of darkness and light. Eight isolates morphologically similar to Fusarium species were observed after 6 days of incubation. For identification, monosporic isolates were transferred onto PDA and carnation leaf agar (CLA) to grow at the conditions described above (1). One isolate, when grown on PDA, rapidly produced abundant, dense, white, aerial mycelium that became pink with age and formed red pigments in the medium. On CLA, macroconidia were abundant, relatively slender, curved to lunate, and three to five septate. Microconidia were abundant, napiform, oval or pyriform, zero to one septate, and commonly clustered in false heads. Chlamydospores were absent. The fungus was identified as Fusarium tricinctum (Corda) Saccardo on the basis of fungal morphology (1). To complete Koch's postulates, the pathogenicity of the fungus was tested by spraying five healthy inflorescences (on average 16 spikelets per spike) of wheat with a 5-ml suspension (2 × 10 5 conidia per ml). Another two healthy inflorescences were sprayed with sterile distilled water. Plants were placed in a growth chamber with a 12-h photoperiod at 22 ± 2°C, covered with polyethylene bags that were removed after 3 days, and then moved to a glasshouse. The same procedure was repeated. While control inflorescences were asymptomatic, inoculated inflorescences showed a mean of five bleached spikelets per spike. By using the methodology described above, the fungus was reisolated from all infected grains of inoculated plants but not from the controls. To confirm the morphological diagnosis, the genomic DNA of the isolate was extracted (3) and the internal transcribed spacer (ITS) and the translation elongation factor (TEF) regions were PCR-amplified using primer pairs ITS3/ITS4 (4) and EF-1/EF-2 (2), respectively. The sequences were compared with those in GenBank. The ITS sequence (Accession No. HM635739) showed 100% similarity with several F. tricinctum sequences (e.g., Accession Nos. HM068317, FN598932, and EF589873) but also with other Fusarium species such as F. acuminatum. The TEF sequence (Accession No. HQ214681) showed 99 to 100% similarity with Accession Nos. HM068307, EU744838, and EU744837 of F. tricinctum. To our knowledge, this is the first report of F. tricinctum on wheat in Argentina. This species is known to produce fusarin C, enniatins, and moniliformin toxins. Since F. tricinctum can infect different cereal grains, a large-scale survey of cereals from fields throughout Argentina is in progress. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Oxford, UK. 2006. (2) K. O'Donell et al. Proc. Nat. Acad. Sci. USA 95:2044, 1998. (3) S. A. Stenglein and P. A. Balatti. Physiol. Mol. Plant Pathol. 68:158, 2006. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Oat (Avena sativa L.) is widely grown (~200,000 ha) for livestock feed in Argentina. Fusarium spp. affect yield and commercial quality and can cause indirect losses because some Fusarium spp. produce mycotoxins. In December 2008, a study of oat seeds (cv. Graciela INTA) from Trenque Lauquen, Buenos Aires, Argentina was conducted. Seeds (400) were surface sterilized by dipping successively into 70% ethanol for 2 min, 5% sodium hypochlorite for 2 min, rinsed twice in fresh sterilized distilled water, plated on 2% potato dextrose agar (PDA) pH 6, and incubated at 24 ± 2°C with 12-h photoperiods. Six isolates morphologically similar to Fusarium spp. were observed after 6 days of incubation. For identification, monosporic isolates were transferred onto 2% PDA and carnation leaf agar (CLA) to grow with the conditions described above. Two isolates produced abundant, white, aerial mycelium and violet-to-dark (with age) pigments in the PDA. On CLA, macroconidia were abundant, slender, almost straight, thin walled, and usually three to five septate. Microconidia were abundant, usually single celled, oval or club-shaped in chains (less commonly in false heads) on monophialides and polyphialides. Chlamydospores were absent. The fungus was identified as Fusarium proliferatum (Matsushima) Nirenberg on the basis of fungal morphology (1). To complete Koch's postulates, the pathogenicity of the fungus was tested by spraying five healthy inflorescences of oat (cv. Graciela INTA) with a 5-ml suspension (2 × 10 5 conidia/ml). Another two healthy inflorescences were sprayed with sterile distilled water. Plants were placed in a growth chamber with a 12-h photoperiod at 22 ± 2°C and covered with polyethylene bags that were removed after 3 days and plants were moved to a glasshouse. This procedure was repeated. While control inflorescences were asymptomatic, inoculated inflorescences showed bleaching glumes that sometimes became necrotic with some grains that presented pale brown discoloration and necrotic areas. The fungus was reisolated from glumes and grains of inoculated plants and not from controls using the methodology described above. To confirm the morphological diagnosis, the genomic DNA of the isolates was extracted (3) and a PCR reaction with specific primers 5'-CTTTCCGCCAAGTTTCTTC-3'-forward and 5'-TGTCAGTAACTCGACGTTGTTG-3'-reverse was chosen (2) using the following cycling protocol: initial denaturation step at 95°C for 2 min; 30 cycles at 95°C for 30 s, 55°C for 30 s, 72°C for 45 s; final extension at 72°C for 2 min. Successful amplifications were confirmed by gel electrophoresis. Size of the DNA fragment was estimated using a 100-bp DNA ladder. The reaction was repeated three times. The expected size product (585 bp) was obtained, confirming the identification (2). To our knowledge, this is the first report of F. proliferatum on oat in Argentina. This species is known to produce fumonisins, beauvericin, fusaric acid, fusarins, and moniliformin toxins, among others. Since F. proliferatum can infect different cereal grains, a large-scale survey in the same and different fields is in progress. A voucher culture has been deposited in the LPSC (Culture Collection of the La Plata Spegazzini Institute) No. 1058. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Oxford, UK. 2006. (2) G. Mule et al. Eur. J. Plant Pathol. 110:495, 2004. (3) S. A. Stenglein and P. A. Balatti, Physiol. Mol. Plant Pathol. 68:158, 2006.

A molecular phylogenetic analysis of Fusarium poae isolates from South America (Argentina) and Europe (mainly England, Germany, Italy) was performed using 98 F. poae, four Fusarium culmorum, two Fusarium sporotrichioides and one Fusarium langsethiae isolates. Phylogenetic analyses were performed using nuclear (translation elongation factor 1-alpha, EF-1 alpha) and mitochondrial (mitochondrial small subunit rDNA, mtSSU) sequences. Partitioned (each dataset separately) and combined (EF-1 alpha+mtSSU) analyses did not reveal any clear correlations from the inferred branching topology, between the distribution of observed haplotypes and the geographic origin and/or host species. Results from the present study confirmed that isolates from F. poae form a monophyletic group, and the low variability within isolates from a broad geographic range suggests a common lineage history. Among F. poae isolates from Argentina, however, some were found to possess an insert within mtSSU with structural similarities to group IC2 introns. F. poae isolates differing by the presence/absence of a mtSSU insertion were characterized further by analysis of a portion of the Tri5 gene, but this sequence was unable to reveal variability. The presence of this insert only within isolates from Argentina suggests that evolutionary events (insertions/deletions) are probably taking place within the Argentinian F. poae isolates, and that the acquisition of this insert occurred after geographic isolation of the Argentinian and European populations., (Copyright © 2009 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

Pseudocercospora griseola is the causal agent of angular leaf spot of common bean (ALS). It has undergone parallel coevolution with its host and two major groups have been defined, "Andean" (P. griseola f. griseola) and "Mesoamerican" (P. griseola f. mesoamericana). The aim of this study was to analyze the nature and the level of the dark pigment synthesized by the representatives of each group. After 21 days of incubation on potato dextrose agar medium, P. griseola f. griseola isolate S3b developed colonies with diameters of 17.5 +/- 1.3 mm and concentric rings of pigmentation. Isolate T4 of P. griseola f. mesoamericana presented smaller colonies (9.9 +/- 0.3 mm) with a uniform dark-gray color. Both isolates, S3b and T4, produced the same pigment, a 1,8-dihydroxynaphthalene-melanin, although different in quantity and structural features as suggested by the IR spectrum. The P. griseola f. griseola isolate S3b had a higher growth rate and melanin content as well as smaller sensitivity to melanin synthesis inhibitors compared to the isolate T4 of P. griseola f. mesoamericana. These results suggest a possible link between melanin and growth in P. griseola.

Angular leaf spot (ALS), caused by Phaeoisariopsis griseola (Sacc.) Ferraris, is one of the most destructive and widespread problems of common bean (Phaseolus vulgaris L.) in Tucumán and other northwestern provinces of Argentina (4). Symptoms similar to those of ALS were observed during April 2005 on most plants of runner bean (P. coccineus L.) in an 80-ha field in Tafí del Valle, Tucumán (2,000 m above sea level). Leaf lesions were brown to gray, irregular to angular to circular, and 0.5 to 1 cm in diameter. Lesions on pods were oval to circular with reddish brown centers surrounded by darker brown borders. Conidia in vivo were curved cylindrical to obclavate with one to five septa and measured 25 to 60 × 3.5 to 7 μm. The conidiophores were 100 to 250 μm high and clustered together to form synnemata measuring 20 to 50 μm in diameter. The pathogen was isolated by placing conidia from diseased leaves onto potato dextrose agar (PDA) at pH 6. Colonies measuring 2 to 3 mm in diameter composed of dense, dark olive mycelium developed after incubation in the dark at 24 ± 2°C for 3 to 4 days. Pathogenicity of the isolate was tested with conidia obtained from the second subculture of 14-day-old colonies on PDA. Conidial suspensions of 2 × 10 4 conidia per ml were sprayed onto the upper and lower surfaces of the first trifoliolate leaves of six runner bean plants, 18 days after planting. Inoculated and control plants (sprayed with distilled water) were placed in a growth chamber with a 12-h photoperiod at 24 ± 2°C and 95 to 100% relative humidity and 48 h later moved to the greenhouse. Disease symptoms were evaluated 18 days after inoculation. While control plants were healthy, all inoculated plants showed symptoms similar to those observed in the field. The fungus that was consistently reisolated from lesions in the inoculated plants was identified as Phaeoisariopsis griseola on the basis of fungal morphology (1), symptoms produced on leaves (3), and random amplified polymorphic DNA data with primer 5'-CAATCGCCGT-3' (2). Runner bean is a new crop in Tafí del Valle, which is a geographically isolated area. In a period of only 2 years, the area cultivated with beans increased approximately five-fold. Because of this, the presence of a pathogen like Phaeoisariopsis griseola, which causes considerable reduction in yield in most common bean-producing areas of Argentina, is of concern. To our knowledge, this is the first report of ALS occurring on P. coccineus in Argentina. This report may prompt the inclusion of regular testing of seeds for ALS in P. coccineus-production areas. A voucher culture has been deposited in the LPSC (Culture collection of the La Plata Spegazzini Institute) No. 844. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK, 1971. (2) P. Guzmán et al. Plant Dis. 83:37, 1999. (3) A. W. Saettler. Pages 15-16 in: Compendium of Bean Diseases. R. Hall, ed, The American Phytopathological Society, St. Paul, 1991. (4) S. A. Stenglein et al. Pages 209-243 in: Advances in Applied Microbiology, Vol. 52. A. I. Laskin et al., eds, Academic Press, San Diego, 2003.