Abstract The use of fungi and bacteria with pathogenic capacity towards insects is considered a sustainable agroecological alternative for efficient pest control, as they are microorganisms of easy production in industrial scale, formulation and use. Therefore, the objective was to evaluate four entomopathogenic formulations in the control of Brevicoryne brassicae L., a key pest of cabbage (Brassica oleracea L.), in a randomized complete block design with 4 treatments, plus an absolute control and 4 replicates. The variables evaluated were the number of dead and live aphids per plant and the number of infested plants. The commercial formulations Biosafe, BesT-K, Metarrizo and Yurak containing strains of Bacillus subtilis, Bacillus thuringiensis var kurstaki (Btk), Metarhizium anisopliae and Bauveria bassiana respectively, are the ones that were used by spray application to the crop in two seasons: planting, season August-December 2019 and August-December 2021. Among the results, M. anisopliae was recorded with up to 91.11 % efficiency, followed by B. bassiana with 89.50 % and Bs with 79.38 % in the reduction of populations under field conditions. In the laboratory, Btk and M. anisopliae reached 100 % mortality in a period of seven days, so it is concluded that in the medium term, entomopathogenic fungi in the field are more efficient in aphid control; however, in controlled conditions Btk is also efficient.

Resumen El uso de hongos y bacterias con capacidad patogénica hacia los insectos se considera una alternativa agroecológica sostenible de lucha eficiente contra las plagas por ser microorganismos de fácil producción en escala industrial, formulación y uso; entonces, el objetivo ha sido evaluar cuatro formulados entomopatógenos en el control de Brevicoryne brassicae L, plaga clave de la col (Brassica oleracea L.), en diseño de bloques completos al azar de 4 tratamientos, sumado un testigo absoluto y 4 réplicas, siendo las variables evaluadas la cantidad de pulgones muertos y vivos por planta y cantidad de plantas infestadas. Los formulados comerciales Biosafe, BesT-K, Metarrizo y Yurak que contenían cepas de Bacillus subtilis, Bacillus thuringiensis var kurstaki (Btk), Metarhizium anisopliae y Bauveria bassiana, respectivamente, son los que fueron utilizados mediante la aplicación por aspersión al cultivo en dos épocas de siembra, temporada agosto-diciembre 2019 y agosto-diciembre 2021. Entre los resultados se registró al M. anisopliae con hasta 91,11 % de eficiencia, seguida por B. bassiana con 89,50 % y Bs con 79,38 % en la reducción de las poblaciones en condiciones de campo; en laboratorio el Btk y M. anisopliae alcanzaron el 100 % de mortalidad en un lapso de siete días, por lo que se concluye que a mediano plazo los hongos entomopatógenos en campo resultan ser más eficientes en el control del pulgón, sin embargo, en condiciones controladas el Btk también es eficiente.

Abstract Introduction.Soybean establishes a symbiosis with Bradyrhizobium japonicum that allows it to fix atmospheric N. Coinoculation with other plant growth-promoting microorganisms can increase Biological Nitrogen Fixation (BNF) and plant growth. Objective. Determine if inoculation with P-solubilizing fungi (SP), Aspergillus flavus (S1) and Trichoderma longibrachiatum (S2), affects growth and BNF variables in soybeans. Materials and methods. In the greenhouse on an Andisol and an Ultisol, growth variables and BNF were evaluated in soybeans inoculated with B. japonicum and 2 SPs. Five treatments were evaluated: an absolute control (T), addition of phosphate rock (RF), addition of RF and inoculation with B. japonicum (BRF) and the addition of RF, B. japonicum and the 2 SPs independently (BRFS1 and BRFS2). An unrestricted randomized design with 4 repetitions was established and the data was analyzed according to normality, either with ANDEVA and DGC at 5% or Kruskal Wallis at 5%. Results. The responses obtained showed a positive effect on the evaluated variables when soybeans were inoculated with SP in addition with B. japonicum. The effect was a trend in Andisol, for the variables aerial fresh weight and number of nodules and their dry weight, while for Ultisol significance was found for these same variables, as well as for aerial dry weight, leaf area and N content and foliar P, with the greatest effect in BRFS2. In absolute terms, the highest P content in the soil microbial biomass and the highest SP population was found in the treatment with the presence of S2. The populations of N Fixers (NF) in the soil were higher for T and RF that did not have inoculation with B. japonicum. Conclusion. Inoculation with SP fungi can positively affect BNF, foliar N and P amounts as well as soybean plant growth.

Resumen Introducción. La soya establece una simbiosis con Bradyrhizobium japonicum para fijar N atmosférico. La coinoculación con otros microorganismos promotores del crecimiento (MPC) puede incrementar la Fijación Biológica de Nitrógeno (FBN) y el crecimiento de las plantas. Objetivo. Determinar si la inoculación con los hongos solubilizadores de P (SP), Aspergillus flavus (S1) y Trichoderma longibrachiatum (S2), afecta variables de crecimiento y de FBN en soya. Materiales y métodos. En un Andisol y un Ultisol en invernadero, se evaluaron variables de crecimiento y FBN en soya inoculada con B. japonicum y 2 SP. Se evaluaron 5 tratamientos: un testigo absoluto (T), adición de roca fosfórica (RF), adición de RF e inoculación con B. japonicum (BRF) y la adición de RF, B. japonicum y los 2 SP de manera independiente (BRFS1 y BRFS2). Se estableció un diseño irrestricto al azar con 4 repeticiones y los datos se analizaron según la normalidad, con ANDEVA y DGC al 5% o Kruskal Wallis al 5%. Resultados. Se obtuvo un efecto positivo sobre las variables evaluadas, cuando la soya se inoculó con los SP además de B. japonicum. El efecto fue tendencia en el Andisol, para las variables peso fresco aéreo y número de nódulos y su peso seco, mientras que para el Ultisol se encontró significancia para estas mismas variables, así como para el peso seco aéreo, área foliar y contenido de N y P foliar, el efecto fue mayor en BRFS2. En términos absolutos el mayor contenido de P en la biomasa microbiana del suelo y la mayor población de SP se encontró en el tratamiento con la presencia de S2. Las poblaciones de Fijadores de N fueron mayores para T y RF. Conclusión. La inoculación con hongos SP puede afectar positivamente la FBN, las cantidades de N y P foliar así como el crecimiento de las plantas de soya.

Transmission line silicon rubber insulators are frequently subjected to harsh environmental conditions that can change their surface characteristics and result in a transient or permanent loss of hydrophobicity. Algae, fungi, mould, and lichen are examples of biological growth that can compromise the power system's ability to operate safely by lowering the insulator's flashover voltage. We evaluated and identified the major microorganisms that could be responsible for the flashovers of insulators in South Africa. Due to the difficulty of accessing insulators currently in use within the electricity network, only two insulators, from two provinces in South Africa, were used in the study. Although algae were not found on the insulators, two major filamentous fungi identified as Curvularia sp. and Aspergillus sp. were isolated. The absence of algae could be attributed to the weather pattern of the two locations where the insulators were placed during their use as part of the network. According to previous studies worldwide, the high occurrence of these fungi could be linked to the reduction of flashover voltage of the composite insulators. Although a larger survey including more insulators from all provinces in South Africa should be conducted, the current study demonstrates the need for a cleaning programme for insulators using cost-effective eco-friendly antimicrobial agents. SIGNIFICANCE: • Degradation and loss of hydrophobicity on the overhead line composite due to biological growth were found to be an impediment to the safe operation of high-voltage insulators. Fungi were found to be the main factor causing the degradation of overhead transmission lines. • With these data, a model can be developed to predict the rate of biological growth on a given insulator, to estimate the degradation of the surface conditions with time for the utility to know when to remove them from the line. Such a model could lead to a more reliable and efficient power system and reduce the engineer's workload.

Abstract The wilt or damping-off of husk tomato is a disease caused by fungi originating in the soil, among which Fusarium oxysporum, Macrophomina phaseolina, and Rhizoctonia solani stand out, causing losses due to the lack of resistant varieties. This study aimed to determine the response of husk tomato (Physalis ixocarpa Brot.), Dalí, Siqueiros, and Tamayo hybrids, as well as cv. Gabriela, Puebla, San Miguel, and Tecozautla, to pathogenic isolates of F. oxysporum, M. phaseolina, and R. solani. The study was conducted under greenhouse conditions; sterilized substrate of river sand + peat (1:3 v/v) was placed in pots and then inoculated with three isolates of F. oxysporum 1.6x105 CFU, two of M. phaseolina, and three of R. solani (8 g of infested sorghum seed/pot, of each fungus). Five seeds of the corresponding husk tomato cultivar were deposited in each pot, then covered with the same substrate and incubated for 30 days. A completely randomized design was used, with three repetitions (pots). In the control treatment, the seeds were sown on soil without fungus. The emergence of seedlings was estimated nine days after sowing (das), and the severity of infection for each of the pathogens (scale of 0-5) at 30 das. Data were analyzed using nonparametric statistics. The seven cultivars tested were susceptible to the species F. oxysporum, M. phaseolina, and R. solani; some of the isolates tested exerted a significant differential effect of virulence on some of the varieties studied.

Resumen La marchitez o secadera del tomatillo es una enfermedad causada por hongos con origen en el suelo, entre los que destacan Fusarium oxysporum, Macrophomina phaseolina y Rhizoctonia solani, causando pérdidas por la carencia de variedades resistentes. El objetivo de este estudio fue determinar la respuesta del tomatillo (Physalis ixocarpa Brot.), híbridos Dalí, Siqueiros y Tamayo, así como los cv. Gabriela, Puebla, San Miguel y Tecozautla, hacia aislados patogénicos de F. oxysporum, M. phaseolina y R. solani. El estudio se realizó bajo condiciones de invernadero, en macetas se colocó arena de río + sustrato de turba (1:3 v/v) esterilizado y después se inoculó, con tres aislados de F. oxysporum 1.6x105 UFC, dos de M. paseolina y tres de R. solani (8 g de semilla de sorgo infestada/maceta, de cada hongo). En cada maceta se depositaron cinco semillas del cultivar de tomatillo correspondiente, luego se taparon con el mismo sustrato e incubaron por 30 días. Se utilizó un diseño completo al azar, con tres repeticiones (macetas). En el tratamiento testigo las semillas se sembraron sobre suelo sin hongo. A los nueve días después de la siembra (dds) se estimó la emergencia de plántulas, 30 dds, la severidad de la infección de por cada uno de los patógenos (escala de 0-5). Los datos se analizaron mediante estadística no paramétrica. Los siete cultivares probados fueron susceptibles a las especies F. oxysporum, M. phaseolina y R. solani, algunos de los aislados probados ejercieron un efecto significativo diferencial de virulencia, en algunas de las variedades estudiadas.

Abstract Phytopathogenic nematodes are a threat for agriculture, they cause plant diseases and economic losses worldwide. Currently, the pursuit of compounds of biological origin for nematode biocontrol has become a priority as an environmentally friendly alternative. Microorganisms-derived compounds have several strategies to reduce the populations of infectious juvenile nematodes. Although microorganisms and their metabolites are the focus of literature reports reviews on nematicidal control, interactions between fungi, bacteria, and nematodes, as well as the compounds that are generated in such interactions, are not highlighted. The aim of this review was to discuss the latest advances on chemical compounds secreted by microorganisms and their interaction mechanisms for biological control of phytopathogenic nematodes. Results were organized based on: i) mode of action, ii) infection process, iii) nematicide compounds, iv) interactions and field applications, and v) current challenges. The scope of this review contributes to a better comprehension of the versatility of bacterial and fungal compounds for their use in the development of management plans for nematode control.

Resumen Los nematodos fitopatógenos son una amenaza para la producción agrícola, causando enfermedades en las plantas y pérdidas económicas en todo el mundo. En la actualidad, la búsqueda de compuestos de origen biológico para estos nematodos, como una alternativa amigable con el ambiente, se ha convertido en prioridad. Los compuestos derivados de microorganismos cuentan con diferentes mecanismos de acción para reducir las poblaciones de juveniles infecciosos de nematodos. A pesar de que la literatura reporta revisiones sobre los microorganismos y sus metabolitos nematicidas, no se destacan las interacciones entre hongos, bacterias y nematodos, así como de los compuestos que se generan en tales interacciones. El objetivo de esta revisión fue discutir los avances recientes sobre compuestos químicos secretados por microorganismos y mecanismos de interacción para el control biológico de nematodos fitopatógenos. Los resultados se organizaron en función de i) mecanismos de acción, ii) proceso de infección, iii) compuestos nematicidas, iv) interacciones y aplicaciones a las soluciones en campo y v) desafíos actuales. El enfoque de esta revisión contribuye a una mejor comprensión de la utilidad de los compuestos producidos por bacterias y hongos que permitan incorporarlos en el desarrollo de planes de manejo para el control de nematodos.

Abstract Root-knot nematodes are detrimental to agricultural crops and hard to control once established in the field. The objective of this research was to evaluate the growth, sporulation, and capture in vitro of asexual fungi against Meloidogyne sp. Molecular identification of the asexual fungi included in the study was performed by sequencing the ITS1 region of rDNA. The growth and sporulation of Arthrobotrys sp., Dactylellina sp. and Dactylaria sp. was evaluated in five culture media and two types of substrates (rice husks and ground corn). For the evaluation of attraction and capture of the nematodes, second stage juveniles of Meloidogyne sp. All the evaluated fungal isolates grew and sporulated in the culture media and substrates. The fungi Arthrobotrys sp. (C19-1-1) and Dactylellina sp. (C19-48) showed greater effectiveness in attracting and capturing Meloidogyne sp. The evaluated fungal isolates have the potential to colonize different culture media and substrates. In addition, they can form modified and specialized hyphae that control juvenile Meloidogyne sp. nematodes. Therefore, future studies should focus on evaluating fungal isolates against root-knot nematodes under field conditions.

Resumen Los nematodos formadores de agallas son perjudiciales para los cultivos agrícolas. El objetivo de esta investigación fue evaluar el crecimiento, esporulación y captura de hongos asexuales contra Meloidogyne sp. en condiciones in vitro. La identificación molecular de los hongos asexuales se realizó con PCR utilizando secuencias de la región ITS del ADNr. Se evaluó el crecimiento y esporulación de Arthrobotrys, Dactylellina y Dactylaria en cinco medios de cultivos y dos tipos de substratos (cascarilla de arroz y maíz molido). Para la evaluación de atracción y captura de los nematodos se emplearon juveniles de segunda etapa de Meloidogyne sp. Todos los aislamientos fúngicos evaluados crecieron y esporularon en los medios de cultivos y substratos. Los hongos Arthrobotrys sp. (C19-1-1) y Dactylellina sp. (C19-48) mostraron mayor efectividad en la atracción y captura de Meloidogyne sp. Los aislamientos fúngicos evaluados tienen el potencial de colonizar diferentes medios de cultivos y substratos. Además, pueden formar hifas modificadas y especializadas que controlan nematodos juveniles de Meloidogyne sp. Por lo tanto, los futuros estudios se deberían centrar en evaluar los aislados fúngicos contra los nematodos formadores de agallas en condiciones de campo.

Abstract Nowadays, fungal contamination of medical Cannabis inflorescences during postharvest has become an increasingly frequent and worrisome problem for consumers and the industry in general. This is because some of these microorganisms can produce secondary metabolites, such as mycotoxins, which can be toxic to humans. To assess the risk posed by fungal contamination and evaluate the potential for fungal isolates to produce mycotoxins, samples of medicinal Cannabis were tested for the presence of mycotoxin-forming fungi. Inflorescences were isolated on PDA agar at 23 ± 2 °C for ten days, and the microorganisms were identified. The strain with morphological characteristics compatible with the genus Aspergillus spp. was selected as the fungus with the highest risk of forming hazardous mycotoxins. This isolate was characterized conventionally and by molecular identification using primers for the internal transcribed spacer region (ITS) of ribosomal DNA and different coding genes and was identified as Aspergillus westerdijkiae. To determine mycotoxin formation, the genome of A. westerdijkiae was sequenced using the Illumina Novaseq platform in South Korea. The antiSMASH tool was used to search for gene clusters associated with producing secondary metabolites, and genes related to toxins were manually curated. Regions where the cluster of genes directly involved in OTA biosynthesis (otaA, otaB, otaC, otaR and otaD) were found, suggesting a potential risk of synthesis of this toxin.

ABSTRACT: This study addresses the need to understand the presence of functional microorganisms in tropical soils, providing valuable information for conservation and sustainable management. The main objective is to analyze the variability of functional microorganisms at different soil depths and their correlations with physicochemical parameters. To this end, soil samples were collected from 15 random points in a reserved forest and analyzed for physicochemical and microbiological properties at two depths (10 and 20 cm). The following functional microorganisms were quantified: viable aerobes, lactobacilli, actinomycetes, fungi, and nitrogen-fixing bacteria using specific protocols. The non-parametric Wilcoxon test was used to determine differences between depths, and the Pearson correlation coefficient (|ρ| ≥ 0.8) was used to analyze correlations between physicochemical parameters and microorganisms. The results suggest that the abundance of viable aerobic microorganisms, Lactobacillus, Actinomycetes, and Fungi decreases with soil depth, while nitrogen-fixing bacteria show no significant differences. The decrease in abundance is related to factors such as nutrient and oxygen availability and microenvironmental conditions. There is a strong positive correlation between the amount of viable aerobic microorganisms and Lactobacillus with phosphorus content, and a negative correlation between Actinomycetes and clay content. Actinomycetes prefer sandy soils, while Fungi thrive in soils rich in organic matter. The negative correlation between Fungi and Actinomycetes suggests competition for limited resources and possible chemical interactions, such as the production of antibiotic compounds by Actinomycetes. This study demonstrates that a detailed understanding of soil microbiota can offer new opportunities to improve agricultural practices, especially in terms of soil fertility management and environmental sustainability.

RESUMEN: Este estudio aborda la necesidad de entender la presencia microorganismos funcionales en suelos tropicales, proporcionando información valiosa para la conservación y manejo sostenible. Tiene como principal objetivo analizar la variabilidad de microorganismos funcionales en diferentes profundidades del suelo y las correlaciones con los parámetros fisicoquímicos. Para ello se recolectaron muestras de suelo de 15 puntos aleatorios en un bosque reservado y se analizaron propiedades fisicoquímicas y microbiológicas a dos profundidades (10 y 20 cm). Se cuantificaron los siguientes microorganismos funcionales: aerobios viables, lactobacilos, actinomicetos, hongos y bacterias fijadoras de nitrógeno utilizando protocolos específicos. Se empleó la prueba no paramétrica de Wilcoxon para determinar diferencias entre profundidades y el coeficiente de correlación de Pearson (|ρ| ≥ 0,8) para analizar correlaciones entre parámetros fisicoquímicos y microorganismos. Los resultados sugieren que la abundancia de microorganismos aerobios viables, Lactobacillus, Actinomicetos y Fungi disminuye con la profundidad del suelo, mientras que las bacterias fijadoras de nitrógeno no muestran diferencias significativas. La disminución de la abundancia se relaciona con factores como la disponibilidad de nutrientes y oxígeno y las condiciones microambientales. Existe una correlación positiva fuerte entre la cantidad de microorganismos aerobios viables y Lactobacillus con el contenido de fósforo, y una correlación negativa entre Actinomicetos y el contenido de Arcilla. Los Actinomicetos prefieren suelos arenosos, mientras que los Fungi prosperan en suelos ricos en materia orgánica. La correlación negativa entre Fungi y Actinomicetos sugiere competencia por recursos limitados y posibles interacciones químicas, como la producción de compuestos antibióticos por parte de los Actinomicetos. Este estudio demuestra que la comprensión detallada de la microbiota del suelo puede ofrecer nuevas oportunidades para mejorar las prácticas agrícolas, especialmente en términos de gestión de la fertilidad del suelo y sostenibilidad ambiental.

ABSTRACT: Piura is the region with the largest organic banana production in Peru; however, the post-harvest disease crown rot has generated large economic losses. Therefore, the following objectives were raised: to evaluate the efficacy of biofungicides in vitro and in vivo for the control of this disease. The products used were: oregano extract, citric acid; ascorbic acid, bioflavonoids; biofertilizer and tea tree oil. In vitro, the "poisoned medium" method was used. In vivo, fruits were inoculated with conidial suspensions at 1 x 104 CFU ml-1 of the phytopathogens Thielaviopsis paradoxa and Colletotrichum musae. The biofungicides were prepared according to the commercial dose. The products were applied, and the fungi were inoculated with manual sprayers. The banana clusters with treatment were placed in 18,4 kg cardboard boxes and packed, incubating at 13 °C for 18 days and 4 days in a maturation chamber with ethylene gas. In vitro, the biofungicides: oregano extract (1450 ppm) and citric acid (2825 ppm) obtained 100% inhibition in the growth of the mycelium of T. paradoxa and C. musae. In fruits, the lowest severity index was for the citrus extract biofungicide (4275 ppm), registering 0,0% against T. paradoxa and C. musae.

RESUMEN: Piura es la región con mayor producción de banano orgánico en el Perú; sin embargo, la enfermedad post cosecha de la pudrición de la corona ha generado grandes pérdidas económicas. Por lo cual, se planteó los siguientes objetivos: evaluar la eficacia de biofungicidas in vitro e in vivo para el control de esta enfermedad. Los productos usados fueron: extracto de orégano, ácido cítrico; ácido ascórbico, bioflavonoides; biofertilizante y aceite del árbol de té. In vitro se utilizó el método del “medio envenenado”. In vivo, se inocularon a frutos con suspensiones de conidias a 1 x 104 UFC mL-1 de los fitopatógenos Thielaviopsis paradoxa y Colletotrichum musae. Se prepararon los biofungicidas según la dosis comercial. Se aplicaron los productos y se inocularon los hongos con asperjadores manuales. Los clústeres de banano con tratamiento se embalaron en cajas de cartón de 18,4 kg y fueron embaladas incubándose a 13 °C durante 18 días y 4 días en cámara de maduración con gas etileno. En in vitro los biofungicidas: extracto de orégano (1450 ppm) y ácido cítrico (2825 ppm) obtuvieron 100% inhibición en el crecimiento del micelio de T. paradoxa y C. musae. En in vivo los frutos el menor índice de severidad lo fue para el biofungicida extracto de cítricos (4275 ppm) registrándose 0,0% frente a T. paradoxa y C. musae.

Resumo Os fungos endofíticos são um grupo ubiquituo que colonizam todas as espécies de plantas na terra. Os estudos que comparam a localização dos fungos endofíticos dentro das folhas de Manihot esculenta Crantz (mandioca) e o tempo de amostragem são muito escassos. Neste estudo, folhas maduras de M. esculenta foram coletadas do Panamá com a finalidade de comparar a diversidade cultivável de endófitos e determinar sua distribuição dentro das folhas. Um total de 170 endófitos foram isolados de 97 espécies que representam 13 gêneros e 8 morfoespécies determinadas como micélios esterilizados contendo 63 isolados. Os fungos Cladosporium, Nigrospora, Periconia e mycelia sterilia 1 e 3 foram os isolados mais predominantes. Também detectamos que os endófitos variaram ao longo do tempo de amostragem, mas não entre os locais dentro das folhas. A composição de endófitos na amostragem e localização de endófitos dentro da folha foi semelhante, exceto para Periconia e mycelia sterilia 3 e 7. Os dados gerados neste estudo contribuem para o conhecimento da biodiversidade de fungos endofíticos no Panamá e estabelecem as bases para pesquisas sobre o entendimento da função de endófitos em culturas de M. esculenta.

Abstract Endophytic fungi are a ubiquituos group that colonize all plant species on earth. Studies comparing the location of endophytic fungi within the leaves and the sampling time in Manihot esculenta Crantz (cassava) are limited. In this study, mature leaves of M. esculenta from Panama were collected in order to compare the cultivable diversity of endophytic fungi and to determine their distribution within the leaves. A total of one hundred sixty endophytes belonging to 97 species representing 13 genera and 8 morphospecies determined as mycelia sterilia that containing 63 isolates were isolated. Cladosporium, Nigrospora, Periconia, and mycelia sterilia 1 and 3 were the most predominant isolated endophytes. We detected that endophytes varied across the sampling time, but not amongst locations within leaves. The endophytes composition across sampling and the location of endophytes within leaf was similar, except for Periconia and mycelia sterilia 3 and 7. The data generated in this study contribute to the knowledge on the biodiversity of endophytic fungi in Panama, and establish the bases for future research focused on understanding the function of endophytes in M. esculenta crops.

Resumo A esporulação de Didymella bryoniae in vitro é de grande importância para estudos que requerem inóculo puro e em grandes quantidades. Assim, os objetivos deste estudo foram identificar a melhor condição para esporulação de D. bryoniae combinando diferentes espectros de luz (luz UV-A ou UV-B, luz branca e escuro contínuo) com distintos meios de cultura (PDA, V8, ML e PDAB) e, avaliar a sobrevivência do fungo armazenado a -20°C ao longo do tempo. As amostras de fungo só esporularam quando submetidas ao tratamento com luz UV-B, independentemente do meio de cultura. Maior aparecimento de esporos do tipo conídio foi observado no meio PDAB, e a menor produção ocorreu no meio ML. Estruturas reprodutivas, como peritécios e picnídeos, foram observadas em todos os meios de cultura. No entanto, houve uma variação considerável na quantidade de cada estrutura entre os diferentes meios de cultura. Os meios ML e V8 apresentaram maior número de peritécios e os meios PDA e PDAB apresentaram maior proporção de picnídeos em relação aos peritécios. A duração do armazenamento a -20°C não afetou o crescimento micelial ou a taxa de crescimento micelial. Em conclusão, a luz UV-B é essencial para a esporulação de D. bryoniae in vitro. Além disso, a composição do meio de cultura influencia o tipo de estrutura fúngica produzida, bem como o tamanho e a quantidade dos esporos. O congelamento a -20°C é uma técnica eficiente que pode ser usada para armazenar D. bryoniae por pelo menos cinco meses sem perda de viabilidade

Abstract The in vitro sporulation of Didymella bryoniae is of great importance for studies that require pure inoculum and in large quantities. Thus, the objectives of this study were to identify the best condition for D. bryoniae sporulation combining different light spectra (UV-A or UV-B light, white light, and continuous dark), with distinct culture media (PDA, V8, ML, and PDAB) and, to evaluate fungus’ survivability stored at -20°C over time. The fungus samples were only able to sporulate when subjected to the UV-B light treatment, regardless of the culture medium. The highest appearance of spores conidium type was observed in the PDAB medium, and the lowest production occurred in the ML medium. Reproductive structures, such as perithecia and pycnidia, were observed in all culture media. However, there was considerable variation in the amount of each structure between the different culture media. The ML and V8 media showed a greater number of perithecia and the PDA and PDAB media presented a greater proportion of pycnidia compared to perithecia. The storage duration at -20°C did not affect mycelial growth or mycelial growth rate. In conclusion, the UV-B light is essential for D. bryoniae in vitro sporulation. Moreover, the culture medium composition influences the type of fungal structure produced, as well as spores’ size and quantity. Freezing at -20°C is an efficient technique that can be used to store D. bryoniae for at least five months without loss of viability.

Resumo Este trabalho teve como objetivo avaliar o efeito da aplicação de plasma atmosférico na inativação de fungos na superfície de sementes de Erythrina velutina e em colônias fúngicas isoladas. Dois experimentos foram realizados em delineamento inteiramente casualizado: no primeiro, o plasma foi aplicado na superfície das sementes usando gás hélio e plasma atmosférico por três, seis e nove minutos, além do controle (sementes sem tratamento), constituindo sete tratamentos com cinco repetições cada; no segundo experimento, placas de Petri contendo o inóculo de diferentes fungos foram tratadas com plasma atmosférico por três, seis e nove minutos (Air-3, Air-6 e Air-9) e comparadas com fungos não tratados em placas de Petri sem tratamento (controle), totalizando quatro tratamentos e cinco repetições cada. Descobrimos que a aplicação de plasma atmosférico nas sementes de E. velutina por nove minutos teve efeito antimicrobiano sobre os fungos Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp. e Rhizopus sp. A formação de colônias fúngicas isoladas de sementes de E. velutina também foi inibida por três minutos de exposição à aplicação de plasma atmosférico, exceto para A. niger, cuja inibição ocorreu a partir de 6 minutos de exposição à aplicação de plasma atmosférico.

Abstract This study aimed to evaluate the effect of atmospheric plasma application on the inactivation of fungi on the surface of Erythrina velutina seeds and on isolated fungal colonies. Two experiments were conducted using a completely randomized design. First, plasma was applied to the surface of the seeds using helium gas and atmospheric plasma for 3, 6, and 9 min in addition to the control (untreated seeds), constituting seven treatments with five repetitions each. In the second experiment, Petri dishes containing the inoculum of different fungi were treated with atmospheric air plasma for 3, 6, and 9 min (Air-3, Air-6, and Air-9) and were compared with untreated fungi in Petri dishes without treatment (control), totaling four treatments and five repetitions each. We found that the application of atmospheric air plasma to E. velutina seeds for 9 min had an antimicrobial effect on the fungi Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp., and Rhizopus sp. The formation of fungal colonies isolated from E. velutina seeds was also inhibited by 3 min of exposure to atmospheric air plasma, except for A. niger, whose inhibition occurred after 6 min of exposure to atmospheric plasma.

Resumo O setor florestal brasileiro se destaca pela tecnologia, práticas de manejo florestal, responsabilidade social e ambiental e, principalmente, alta produtividade, mas pragas exóticas podem reduzir isto. O parasitoide Psyllaephagus bliteus (Riek, 1962) (Hymenoptera: Encyrtidae), percevejos predadores e fungos entomopatogênicos como Beauveria bassiana e Metarhizium anisopliae são inimigos naturais usados no controle biológico do psilídeo-de-concha do eucalipto Glycaspis brimblecombei (Moore, 1964) (Hemiptera: Aphalaridae), praga em plantios de eucalipto. A utilização de fungos entomopatogênicos contra pragas exóticas vem aumentando no setor florestal e a prospecção e identificação de isolados fúngicos é importante para o manejo integrado de pragas. O objetivo deste estudo foi o isolamento e identificação molecular de Cordyceps spp. e avaliar a patogenicidade dos isolados de Cordyceps javanica (LCBPF 11) e Cordyceps fumosorosea (LCBPF 12 e LCBPF 63), obtidos de adultos de Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), ao psilídeo-de-concha G. brimblecombei. Os fungos foram isolados de adultos de B. tabaci encontrados em culturas de soja e tomate e identificados molecularmente. Os conídios foram suspensos em solução com Tween 80 (0,1%) na concentração de 1,0 x 108 conídios/mL e pulverizados sobre dez ninfas de G. brimblecombei por folha de Eucalyptus cortada e colocada sobre gel hidrorretentor no interior de placas de Petri por repetição. O número de insetos mortos foi quantificado, diariamente, por sete dias e transferidos para câmaras úmidas. Cordyceps javanica (LCBPF 11) e C. fumosorosea (LCBPF 12 e LCBPF 63) foram identificados por análise molecular e todos os isolados foram patogênicos para os insetos. Isto indica serem importantes para o manejo de G. brimblecombei e confirma relatos de que, normalmente, fungos causam maiores mortalidades em insetos da mesma ordem daquela da qual foram isolados.

Abstract The Brazilian forestry sector stands out for its technology, forestry management practices, social and environmental responsibility and, mainly, for its high productivity and exotic pests can reduce it. The red gum lerp psyllid Glycaspis brimblecombei (Moore, 1964) (Hemiptera: Aphalaridae) is an important pest in Eucalyptus plantations. The parasitoid Psyllaephagus bliteus (Riek, 1962) (Hymenoptera: Encyrtidae), predatory bugs and entomopathogenic fungi such as Beauveria bassiana and Metarhizium anisopliae are the natural enemies and used in the biological control of the red gum lerp psyllid. The use of entomopathogenic fungi against exotic pests is increasing in the forestry sector and the prospecting and identification of fungus isolates is important for integrated pest management. The objective of this work was the isolation and molecular identification of Cordyceps spp. And to evaluate the pathogenicity of isolates, obtained from Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae) adults, against to the red gum lerp psyllid G. brimblecombei. The fungi were isolated from B. tabaci adults found in soybean and tomato crops and molecularly identified. The conidia obtained were suspended in solution with Tween 80 (0.1%) at a concentration of 1.0 × 108 conidia/mL and sprayed on ten G. brimblecombei nymphs per Eucalyptus leaf cut and placed on a hydroretentive gel inside per Petri dishes as a replication. The number of dead insects was quantified, daily, for seven days, and transferred to humid chambers. Cordyceps javanica (LCBPF 11) and C. fumosorosea (LCBPF 12 and LCBPF 63) were identified with a molecular analysis and all isolates were pathogenic to the insects and indicates that they could be used to manage G. brimblecombei and adds to reports that, normally, fungi cause greater mortality on insects of the same order as that from which they were isolated.

Resumo Diversidade molecular, morfológica, perfil químico qualitativo e atividade antioxidante de fungos filamentosos do trato digestivo de Phylloicus sp. (Trichoptera: Calamoceratidae). Este estudo visou identificar por análises molecular, morfológica, química e por extrato antioxidante, fungos filamentosos isolados do trato digestivo de Phylloicus sp, um inseto aquático que vive entre folhagens em riachos tropicais, e participam junto com os fungos da decomposição de substratos vegetais em habitats aquáticos. Larvas de insetos de Phylloicus sp. foram coletadas em riachos no Estado do Tocantins, Brasil. Os fungos foram isolados a partir do trato digestivo das larvas após desinfecção e dissecção, depois descritos e purificados para fins de identificação e testes para atividade antioxidante. A identidade molecular foi realizada do sequenciamento ITS1 e ITS4, TUB e TEF. Os extratos fúngicos foram produzidos em solução etanólica 70% e posterior liofilização. Para análise de grupos químicos dos extratos, foi realizada cromatografia em camada delgada (CCD) em duas fases móveis e diferentes reveladores. A morfologia foi realizada por microscopia óptica corada com Azul de Toluidina e a mensuração realizada no programa ImageJ. A atividade antioxidante realizada em CCD e por método quantitativo para os radicais DPPH e peróxido de hidrogênio (H2O2). Foram identificados quatro fungos: Endomelanconiopsis endophytica, Myxospora musae, Neopestalotiopsis cubana e Fusarium pseudocircinatum. Na CCD foi evidenciado várias manchas com fase móvel acetona/clorofórmio e reveladores UV 254 nm e vapor de I2. Os extratos fúngicos demonstram ação antioxidante para redução do radical livre DPPH e em especial para H2O2 acima de 50%, E. endophytica 91.6%, M. musae 87.8%, N. cubana 89.5% e 92.3% para F. pseudocircinatum. Este estudo demonstrou que a técnica molecular por PCR foi satisfatória para identificação dos fungos, e os extratos com inúmeros grupos químicos e potentes agentes redutores. Com isso, trabalhos futuros deverão ser realizados avaliando essas quatro espécies para uso industrial.

Abstract This study aimed to identify by molecular analysis, morphology, chemistry and antioxidant extracts of filamentous fungi isolated from the digestive tract of Phylloicus sp, an aquatic insect that lives on leaf packages in tropical streams and participates together with fungi of the decomposition of plant substrates in aquatic habitats. Insect larvae of Phylloicus sp. were collected in streams in the state of Tocantins, Brazil. Fungi were isolated from the digestive tract of larvae after disinfection and dissection, then described and purified for identification purposes and testing for antioxidant activity. Molecular identity was performed of ITS1 and ITS4, TUB e TEF sequencing. Fungal extracts were produced in 70% ethanol solution and later lyophilized. For analysis of chemical groups of extracts, thin layer chromatography (TLC) was performed in two mobile phases and different developers. Morphology was performed by optical microscopy stained with Toluidine Blue and measurement performed using the ImageJ program. Antioxidant activity performed in TLC and by quantitative method for DPPH and hydrogen peroxide (H2O2) radicals. Four fungi were identified: Endomelanconiopsis endophytica, Myxospora musae, Neopestalotiopsis cubana and Fusarium pseudocircinatum. The TLC showed several spots with acetone/chloroform mobile phase and UV 254 nm developers and I2 vapor. Fungal extracts demonstrate antioxidant action to reduce the DPPH free radical and especially for H2O2 above 50%, E. endophytica 91.6%, M. musae 87.8%, N. cubana 89.5% and 92.3% for F. pseudocircinatum. This study demonstrated that the molecular technique by PCR was satisfactory for identifying fungi, and extracts with numerous chemical groups and potent reducing agents. Thus future work, should be carried out evaluating these four species for industrial use.