Selenium-containing compounds exhibit diverse biological activities, such as antioxidative, anti-inflammatory, and cancer preventive effects. Using Caenorhabditis elegans as a model organism, we assessed the toxicity, neuroprotective, antioxidant properties, and impact on longevity of 11 selenoacetylenes. Their toxicity and bioactivities varied based on molecular structure. Selenoacetylenes with butyl substituents were toxic to Galleria mellonella larvae. The presence of but-3-in-2-ol radical increased antiprotozoal activity against Tetrahymena pyriformis. Compared to the positive control (Nimitz® EC), selenoacetylenes were less toxic to nematode worms and eggs. Selenoacetylenes significantly reduced amyloid beta (Aβ) paralysis in C. elegans CL4176 worms, increased longevity by 18 to 22%, along with improving survival after oxidative or thermal stress. Galantamine, showed inferior results. These findings enhance our understanding of selenoacetylenes on neuroprotection, antioxidant activity, and longevity in C. elegans. Future mammalian studies will further elucidate mechanisms and explore the potential therapeutic use of selenoacetylenes in treating Alzheimer’s disease and longevity. Seleniumcontaining Selenium containing activities antioxidative antiinflammatory, antiinflammatory anti inflammatory, inflammatory anti-inflammatory effects organism neuroprotective properties 1 structure larvae but3in2ol butinol but 3 2 ol pyriformis Nimitz® Nimitz (Nimitz EC, EC , EC) eggs Aβ (Aβ C CL CL417 22 22% stress Galantamine results neuroprotection Alzheimers Alzheimer s CL41 CL4

Abstract The nematicidal effect of Canavalia ensiformis seed extract combined with silicon dioxide nanoparticles was evaluated on second instar juveniles of Meloidogyne incognita, a phytopathogenic nematode that affects tomato crops. In the first experiment, concentrations of the extract were tested at 2, 4, 6, 6, 8 and 10%, observing that the most effective concentration was 10%, with 90% mortality at 24 hours. In the second experiment, concentrations of the extract at 1.5, 2.0, 2.5 and 3.0% were combined with silicon dioxide nanoparticles at 0.06, 0.08, 0.10, 0.12 and 0.14%, where the most effective was 1.5% extract with 0.14% nanoparticles, which showed a mortality of 94% at 72 hours. These results suggest that the combination of C. ensiformis extract with NP's can be a strategy for the management of M. incognita in tomato crops.

Resumen Se evaluó el efecto nematicida del extracto de semillas de Canavalia ensiformis combinado con nanopartículas de dióxido de silicio, en juveniles de segundo estadio (J2) de Meloidogyne incognita, nematodo fitopatógeno que afecta el cultivo de tomate. En el primer experimento, se probaron concentraciones del extracto al 2, 4, 6, 8 y 10%, observando que la concentración más efectiva fue del 10%, con una mortalidad del 90% a las 24 horas. En el segundo experimento, se combinaron concentraciones del extracto al 1.5, 2.0, 2.5 y 3.0% con nanopartículas de dióxido de silicio al 0.06, 0.08, 0.10, 0.12 y 0.14%, donde la más eficaz fue la de 1.5% de extracto con 0.14% de nanopartículas, que mostró una mortalidad del 94% a las 72 horas. Estos resultados sugieren que la combinación de extracto de C. ensiformis con las NP’s puede ser una estrategia para el manejo de M. incognita en cultivos de tomate.

ABSTRACT: The invasive chinese slug Meghimatiumpictum (Stoliczka, 1873) (Stylommathophora: Philomycidae) is originally from Asia, and it has been introduced in Latin American countries like Argentina and Brazil, where it is considered a critical horticultural pest. This species also became an intermediate host for the nematode AngiostrongyluscostaricensisMorera&Cespedes, 1971(Strongylida: Metastrongylidae), which can cause abdominal angiostrongyliasis in humans when ingested molluscs or their mucus containing larvae released on fruit and vegetables. This research aimed to investigate the biological parameters of the life cycle of M. pictum and evaluate its food preference to understand the species’ behavior and provide information on the choice of safer pest management and control methods. We observed that 68 and 75% of the grouped and isolated slugs, respectively, survived 26 weeks (180 days) under laboratory conditions. In addition, the individuals kept isolated had higher body mass (2.8 ± 0.6 g), length (3.3 ± 0.8 cm), and width (0.37 ± 0.3 cm) than grouped specimens. We also found that M. pictum has indeterminate growth and an annual reproductive cycle. Concerning food preference, slugs better accepted lettuce at different developmental stages (neonate, juvenile, and adult). Our study presents the first description of the M. pictum life cycle. We concluded that M. pictum has undefined biological parameters, which hampers its laboratory rearing. However, we also demonstrate its potential as a pest for different horticultural crops, which will require the development of management strategies. ABSTRACT Stoliczka, Stoliczka (Stoliczka 1873 Stylommathophora (Stylommathophora Philomycidae Asia Brazil AngiostrongyluscostaricensisMoreraCespedes AngiostrongyluscostaricensisMorera Cespedes AngiostrongyluscostaricensisMorera&Cespedes 1971Strongylida Strongylida 1971 1971(Strongylida Metastrongylidae, Metastrongylidae , Metastrongylidae) vegetables M methods 6 75 respectively 2 180 (18 days conditions addition 2.8 28 8 (2. 06 0 0. g, g g) 3.3 33 3 (3. 08 cm, cm 0.37 037 37 (0.3 03 specimens neonate, neonate (neonate juvenile adult. adult . adult) rearing However crops strategies 187 197 7 18 (1 2. (2 3. (3 (0. 19 1 ( (0

RESUMO: A lesma invasora Meghimatium pictum (Stoliczka, 1873) (Stylommathophora: Philomycidae) é originária da Ásia e foi introduzida em países latino-americanos como Argentina e Brasil, onde é considerada uma praga hortícola severa. Esta espécie também se tornou um hospedeiro intermediário do nematoide Angiostrongylus costaricensis Morera & Céspedes, 1971 (Strongylida: Metastrongylidae), que pode causar a infecção angiostrongilíase abdominal em humanos quando ingerido o molusco ou frutas e vegetais contendo o seu muco contaminado com larvas. Esta pesquisa teve como objetivo investigar os parâmetros biológicos do ciclo de vida de M. pictum e avaliar sua preferência alimentar para entender o comportamento da espécie e fornecer informações sobre a escolha futura de métodos mais seguros de manejo e controle desta praga. Observamos que 68 e 75% das lesmas agrupadas e isoladas, respectivamente, sobreviveram 26 semanas (180 dias) em condições de laboratório. Além disso, os indivíduos mantidos isolados apresentaram maior massa corporal (2,8 ± 0,6 g), comprimento (3,3 ± 0,8 cm) e largura (0,37 ± 0,3 cm) do que os espécimes agrupados. Também descobrimos que M. pictum tem crescimento indeterminado e ciclo reprodutivo anual. Com relação à preferência alimentar, a alface foi bem aceita pelas lesmas em diferentes estágios de desenvolvimento (recém-nascido, juvenil e adulto). Nosso estudo apresenta a primeira descrição do ciclo de vida de M. pictum. Concluímos que M. pictum possui parâmetros biológicos indefinidos, com ciclo de vida longo o que dificulta sua criação em laboratório. No entanto, também demonstramos seu potencial como praga para diferentes culturas hortícolas, o que exigirá o desenvolvimento de estratégias de manejo. RESUMO Stoliczka, Stoliczka (Stoliczka 1873 Stylommathophora (Stylommathophora Philomycidae latinoamericanos latino americanos Brasil severa Céspedes 197 Strongylida (Strongylida Metastrongylidae, Metastrongylidae , Metastrongylidae) larvas M 6 75 isoladas respectivamente 2 180 (18 dias laboratório disso 2,8 28 8 (2, 06 0 0, g, g g) 3,3 33 3 (3, 08 cm 0,37 037 37 (0,3 03 agrupados anual recémnascido, recémnascido recém nascido, nascido (recém-nascido adulto. adulto . adulto) indefinidos entanto hortícolas 187 19 7 18 (1 2, (2 3, (3 (0, 1 ( (0

Abstract The broad bean is one of the most important crops in the Central Mexican Plateau due to its adaptation to edaphoclimatic conditions and its high nutritional value in the diet of the inhabitants of this region. Nonetheless, the yields obtained are low compared to the world average. Phytoparasitic nematodes are one of the main constraints to broad bean production in other parts of the world; however, its presence in this crop is unknown in Mexico. In this work, phytoparasitic nematodes associated with broad bean crops were identified and quantified in 10 farms in the municipalities of Tepeyahualco and Cuyoaco, Puebla, and in plants germinated in sterile soil from seeds from different areas in 2022. The following six genera of phytoparasitic nematodes were found: Criconemoides, Ditylenchus, Helicotylenchus, Hoplolaimus, Pratylenchus and Zygotylenchus. The most abundant genera were Ditylenchus and Pratylenchus, with a population density of 11 and 7 specimens per 100 cm3 of soil and 159 and 60 specimens per 100 g of plant tissue, respectively, and they were found in all sampling sites. The population density of Ditylenchus exceeds the economic threshold of the crop; in addition, specimens of this genus were found in plants germinated in sterile soil. The results show that Ditylenchus is distributed throughout the sampled area and can affect yield. Further studies are needed to determine the identity of nematode species and their distribution in other production areas.

Resumen El haba es uno de los cultivos más importantes en el altiplano mexicano, debido a su adaptación a las condiciones edafoclimáticas y a su alto valor nutrimental en la dieta de los habitantes de esta región. Sin embargo, los rendimientos obtenidos son bajos comparado con el promedio mundial. Los nematodos fitoparásitos son una de las principales limitantes para la producción de haba en otras partes del mundo; no obstante, en México se desconoce su presencia en este cultivo. En este trabajo se identificaron y cuantificaron los nematodos fitoparásitos asociados a cultivos de haba en 10 predios de los municipios de Tepeyahualco y Cuyoaco, Puebla y en plantas germinadas en suelo estéril a partir de semillas provenientes de diferentes zonas en el año 2022. Se encontraron seis géneros de nematodos fitoparásitos: Criconemoides, Ditylenchus, Helicotylenchus, Hoplolaimus, Pratylenchus y Zygotylenchus. Los géneros más abundantes fueron Ditylenchus y Pratylenchus con una densidad de población de 11 y 7 ejemplares por 100 cm3 de suelo y 159 y 60 ejemplares por 100 g de tejido vegetal respectivamente y se encontraron en todos los sitios de muestreo. La densidad de población de Ditylenchus sobrepasa el umbral económico del cultivo, además, ejemplares de este género se encontraron en las plantas germinadas en suelo estéril. Los resultados demuestran que Ditylenchus está distribuido en toda la zona muestreada, y puede causar afectaciones en el rendimiento. Es necesario realizar más estudios para determinar la identidad de las especies de nematodos y su distribución en otras zonas de producción.

ABSTRACT Meloidogyne enterolobii is currently the most damaging nematode of the genus Meloidogyne due to its aggressiveness and ability to overcome existing sources of resistance; therefore, the search for genotypes with resistance in crops of high economic importance such as chili pepper (Capsicum annuum L. var. annuum) is one of the greatest challenges facing agricultural researchers. The aim of this study was to determine the level of resistance in C. annuum landraces from Mexico to different population densities of M. enterolobii. Five C. annuum landraces (UTC24, UTC25, UTC66, UTC67, and UTC90) and the commercial cv. Revelation were used. The experiment was conducted twice under greenhouse conditions with a randomized block design with four replicates per genotype and cultivar. Inoculation was performed on 21-d-old seedlings with inoculum doses of 0, 4500, 9000, and 13500 eggs plant-1. The gall index, reproduction factor, and reproduction index were evaluated at 42 and 63 d after inoculation. Genotypes UTC66, UTC67, and UTC90 showed a higher level of resistance with a damage percentage lower than 50% compared to ‘Revelation’ (susceptible). Genotype UTC90 showed the lowest reproduction factor and index, so it was considered a highly resistant genotype to an inoculum dose of 4500 M. enterolobii eggs with a damage percentage of less than 10%, while, at a dose of 13 500 eggs, its resistance level was intermediate. The results of this study contribute to the search for sources of resistance to M. enterolobii in chili pepper landraces.

Abstract The biological control in sugarcane in Venezuela has been established as a unique measure, having optimal results of the use of parasitoids and entomopathogens for the control of borers of the genus Diatraea, and later of the candelilla Aeneolamia spp., both key pests of the crop. For borers it was achieved after systematic releases of the Amazonian fly Lydella minense from the middle of the last century and then with the establishment of the braconid wasp Cotesia flavipes from 1987. For the biological control of Aenolamia varia, pest that involved the frequent application of insecticides, after the introduction of the use of the entomopathogenic fungus Metarhizium anisopliae since 1977, has been established as an efficient measure for the control of its adults, however, the nymphs were less controlled. This aspect was resolved through the introduction of the entomopathogenic nematode Heterorhabditis bacteriophora in 2004, which has been widely used as a biological measure to avoid the application of insecticides. As an example, we have the Azucarera Río Turbio, although in the last harvests it has had a reduction in its areas due to different factors. During the last 58 years, Diatraea infestation shows a reduction of 15 to 3.18 %, which saves 170 552.62 metric tons with a value of US$ 49 196 045 and a cost of biological control of US$ 1 187 189 which translates into a benefit-cost of US$ 41.44. Before the establishment of biological control, Aeneolamia was controlled exclusively with chemical insecticides applied to foliage for adults and soil for nymphs. Simultaneously since then, the entomopathogenic fungus M. anisopliae produced by national companies has been used and this entomopathogen was used on 87 000 hectares between 1986 and 1990. Also since 2004, the methodology of using entomopathogenic nematodes to control Aeneolamia nymphs began.

Resumen El control biológico en caña de azúcar en Venezuela se ha logrado establecer como una medida única, con resultados óptimos del uso de parasitoides y entomopatógenos para el control de los taladradores del género Diatraea, y, posteriormente, de la candelilla Aeneolamia spp., ambas plagas claves del cultivo. Para los taladradores, se logró después de liberaciones sistemáticas de la mosca amazónica Lydella minense desde un inicio, a mediados del siglo XX y luego con el establecimiento de la avispa bracónida Cotesia flavipes, a partir de 1987. Para el control biológico de Aeneolamia varia, plaga que implicaba la aplicación frecuente de insecticidas, después de la introducción del uso del hongo entomopatógeno Metarhizium anisopliae desde 1977, se ha establecido como medida eficiente para el control de sus adultos, aunque las ninfas eran menos controladas. Este aspecto se resolvió mediante la introducción del nematodo entomopatógeno Heterorhabditis bacteriophora en 2004, el cual se viene utilizando en forma general, y prácticamente ya se tienen las medidas biológicas para evitar la aplicación de insecticidas. Como ejemplo se tiene a la Azucarera Río Turbio, aunque en las últimas zafras ha tenido una reducción en sus áreas, por diferentes factores. Durante los últimos 58 años, la infestación de Diatraea muestra una reducción de 15 a 3.18 %, con lo cual se salvan 170 552.62 toneladas métricas (TM), con un valor de US$ 49 196 045 y un costo del control biológico de US$ 1 187 189 lo que se traduce en un beneficio-costo de US$ 41.44. Antes del establecimiento del control biológico, Aeneolamia se controlaba exclusivamente con insecticidas químicos, aplicados al follaje para los adultos y al suelo para las ninfas. Simultáneamente desde entonces, se ha utilizado el hongo M. anisopliae producido por empresas nacionales, hasta cubrir 87 000 ha, entre 1986 y 1990. También, desde 2004 se inició la utilización de nematodos entomopatógenos para el control de ninfas de Aeneolamia.

Summary Background and aims: The false-root knot nematode (Nacobbus spp.) comprises polyphagous species, with pepper (Capsicum annuum) being one of the most affected crops. Due to the lack of resistant pepper genotypes, we compared the responses of different commercial cultivars to identify possible plant defence mechanisms against N. celatus. M&M: Nematodes from Río Cuarto (Córdoba Province) and Lisandro Olmos (Buenos Aires Province) were inoculated on pepper cultivars: California Wonder (control), Fyuco INTA, Yatasto, and Fenomeno RZ. Plants were grown under a greenhouse and galls were analysed by histopathological techniques. Results: The roots of the commercial cultivars showed the typical morpho-anatomical alterations induced by N. celatus: gall formation, hyperplasia reactions, development of syncytia in the central cylinder and disorganisation of vascular tissues. Syncytial cells in contact with females of nematodes from Lisandro Olmos showed a defence reaction by Fyuco INTA, whereas feeding sites in Fenomeno RZ did not denote high metabolic activity in nematodes of both origins. Conclusions: The different responses observed between populations and/or hosts demonstrate the importance of considering nematodes from different geographical origins when testing plant material for tolerance and/or resistance to N. celatus. Studies of this nature are necessary since they facilitate a more in-depth understanding of the parasite-plant interaction.

Resumen Introducción y objetivos: El falso nematodo de la agalla (Nacobbus spp.) comprende especies polífagas, siendo el pimiento (Capsicum annuum) uno de los cultivos más afectados. Debido a la falta de genotipos resistentes del pimiento, comparamos las respuestas de diferentes cultivares comerciales para identificar posibles mecanismos de defensa contra N. celatus. M&M: Nematodos provenientes de Río Cuarto (provincia de Córdoba) y Lisandro Olmos (provincia de Buenos Aires) se inocularon en cultivares de pimiento: California Wonder, Fyuco INTA, Yatasto y Fenomeno RZ. Las plantas se desarrollaron en invernadero y las agallas se analizaron mediante técnicas histopatológicas. Resultados: Las raíces de los cultivares analizados mostraron las alteraciones morfo-anatómicas típicas inducidas por N. celatus: formación de agallas, reacciones de hiperplasia, desarrollo de sincitios en el cilindro central y desorganización de los tejidos vasculares. Las células sincitiales en contacto con hembras de Lisandro Olmos mostraron una reacción de defensa por parte de Fyuco INTA, mientras que los sincitios en Fenomeno RZ denotaron baja actividad metabólica en nematodos de ambas procedencias. Conclusiones: Las diferencias observadas entre las poblaciones y/o hospedadores demuestran la importancia de considerar nematodos de diferentes orígenes geográficos al analizar material vegetal para determinar su tolerancia y/o resistencia a N. celatus. Estudios de esta naturaleza son necesarios ya que facilitan una comprensión más profunda de la interacción parásito-planta.

Abstract Alliaceae crops includes several species of agricultural importance for the Arequipa region, among them the onion is the most produced in the country, however, these crops are affected by phytoparasitic nematodes, including Meloidogyne spp. which causes significant losses in the yield. The aim of the present study was to characterise the root-knot nematode (Meloidogyne spp) and determine the population density of phytoparasitic nematodes in alliaceae crops in the main producing localities of the Arequipa region. Samples of roots and soil were collected in onion, chinese onion, leek and chives crops in the provinces of Arequipa, Castilla, Caylloma and Islay. The identification of nematode genus was found by morphological characteristics and the characterization of Meloidogyne were performed by perineal patterns and electrophoretic pattern of esterase (Est). In the 38 soil samples, different genus of plant-parasitic nematodes was found: Aphelenchus, Dorylaimus, Helicotylenchus, Hemicycliophora, Meloidogyne, Mesocriconema, Mononchus, OGMA, Pratylenchus, Rotylenchus, Tylenchus, Xiphinema and free-living nematodes, in root samples, eight populations of Meloidogyne spp. were found. distributed among three species: (1) M. incognita phenotype Est I1, Rm: 1.0 with 33.33% of frequency and Est I2, Rm: 1.03, 1.07 (50%); (2) M. javanica Est J3, Rm: 1.03, 1.24, 1.37 (16.67%) and an atypical species named Meloidogyne sp. Rm: 0.85 (33.33%). The identification of genus and species phytoparasitic nematodes in alliaceae will allow the adoption of more efficient integrated management measures, because have a distinct parasitism behavior.

Resumen Cultivo de aliáceas comprenden diversas especies de importancia agrícola para la región Arequipa, entre ellas la cebolla es la de mayor producción en el país, sin embargo, estos cultivos son afectados por nematodos fitoparásitos entre ellas Meloidogyne spp. que ocasiona pérdidas significativas en la producción. El objetivo del presente estudio fue caracterizar al nematodo de las agallas (Meloidogyne spp) y determinar la densidad poblacional de nematodos fitoparásitos en cultivos de aliáceas en las principales localidades productoras de la región Arequipa, se colectaron muestras de raíces y suelo de cultivos de cebolla, cebolla china, poro y cebollín en las provincias de Arequipa, Castilla, Caylloma e Islay. La identificación de los géneros de nematodos se hizo mediante características morfológicas y la caracterización de Meloidogyne se hizo mediante patrones perineales y por padrón electroforético de esterasa (Est). En las 38 muestras de suelo se encontraron doce géneros de nematodos fitoparásitos: Aphelenchus, Dorylaimus, Helicotylenchus, Hemicycliophora, Meloidogyne, Mesocriconema, Mononchus, OGMA, Pratylenchus, Rotylenchus, Tylenchus, Xiphinema y nematodos de vida libre, en muestras de raíces, se encontraron ocho poblaciones de Meloidogyne spp. distribuidas en tres especies: (1) M. incognita fenotipo Est I1, Rm: 1.0 con 33,33% de frecuencia y Est I2, Rm: 1.03, 1.07 (50%); (2) M. javanica Est J3, Rm: 1.03, 1.24, 1.37 (16,67%) y una especie atípica denominada Meloidogyne sp. Rm: 0.85 (33,33%). La identificación de géneros y especies de nematodos fitoparásitos en aliáceas, permitirá adoptar medidas de manejo integrado más eficientes, debido a que poseen un comportamiento de parasitismo distinto.

ABSTRACT Integrated management is considered the best strategy to mitigate the damage caused by plant-parasitic nematodes. However, there is still limited information regarding some integrated techniques. Thus, this study aimed to assess the effects of genetic management associated with chemical control of Meloidogyne javanica in soybean (Glycine max (L.) Merr.) The experiment was installed in a greenhouse according to an 8×4 factorial design with eight replicates. The first factor was soybean cultivar (HO Juruena IPRO, resistant; Foco IPRO, HO Maracaí IPRO, and CZ 58B28 IPRO, moderately resistant; HO Mamoré IPRO, moderately susceptible; and Extrema IPRO, CZ 48B32 IPRO, and HO Aporé IPRO, susceptible). The second factor consisted of an untreated control and commercial nematicides based on abamectin, thiodicarb+imidacloprid, and fluopyram. Plants were inoculated with 2000 nematode eggs, and nematode and vegetative variables were evaluated at 65 d after inoculation. There was an interaction effect on nematode variables. Furthermore, there was an additive effect of genetic management and chemical control, mainly in resistant cultivars treated with thiodicarb+imidacloprid or fluopyram with controls of up to 69.90% and 96.86%, respectively. The application of fluopyram and the use of ‘HO Juruena IPRO’, ‘Foco IPRO’, or ‘HO Maracaí IPRO’ also contributed to the control of M. javanica. Vegetative variables were studied by analyzing product effects separately, but results were inconclusive.

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 19. Gastrointestinal parasitism is very common in horses in northeastern Argentina, where it is often subclinical, leading to losses in body development and reduced animal performance. The objective of this study was to characterize the population of gastrointestinal nematodes in horses from the town of Gobernador Virasoro, Corrientes, used in the artisanal production of bricks. An observational cross-sectional descriptive study design was used and non-probability convenience sampling was performed. The number of eggs per gram of feces was determined by coprological examinations (modified McMaster technique), and all samples with the presence of gastrointestinal nematode eggs were considered positive. Morphologically, eggs of the order Strongylida were distinguished from eggs of Parascaris equorum and Oxyuris equi and the possible combinations between them. Parasitic genera of the order Strongylida were identified from pool coprocultures, differentiating between large and small strongyles. The results showed that 94.79% of the samples were positive, of which 83.43% corresponded to the order Strongylida only, 10.98% to the combination with eggs of P. equorum and 5.59% to the combination with eggs of O. equi. The highest average number of eggs belonged to the Strongylida order, with 90.55% corresponding to small strongyles. The results of this study suggest that gastrointestinal parasitism is a major problem in the working horse population of Gobernador Virasoro and could have a negative impact on animal health and performance.

Resumen 15. En el nordeste argentino son muy frecuentes las parasitosis gastrointestinales en los equinos, presentes de forma subclínica, provocando pérdidas en el desarrollo corporal y disminución en el rendimiento de los animales. El objetivo fue caracterizar la población de los nematodos gastrointestinales en equinos de la localidad de Gobernador Virasoro (Corrientes) a través del examen coprológico, utilizados como animal de trabajo en la fabricación artesanal de ladrillos. Se utilizó un diseño de estudio observacional transversal descriptivo, para ello se realizaron muestreos de conveniencia de tipo no probabilísticos. Se realizó el recuento de huevos por gramo de materia fecal mediante estudios coprológicos (técnica de McMaster modificada), donde se consideró como positivas a todas aquellas muestras con presencia de huevos de nematodos gastrointestinales. Se diferenció morfológicamente entre huevos del orden Strongylida y huevos de Parascaris equorum y Oxyuris equi, y las combinaciones que pudieran presentarse entre ellos. Los géneros parasitarios del orden Strongylida se identificaron a partir de coprocultivos en pool diferenciando entre grandes y pequeños estrongilos. El 94,79% de las muestras fueron positivas, de las cuales el 83,43% correspondieron únicamente al orden Strongylida, el 10,98% a la combinación con huevos de P. equorum, y el 5,59% a la combinación con huevos de O. equi. Los mayores promedios de recuentos de huevos pertenecieron al orden Strongylida, donde mediante coprocultivo se determinó que el 90,55% correspondió a pequeños estróngilos. Los resultados de este estudio sugieren que la parasitosis gastrointestinal es un problema importante en la población de equinos de trabajo de Gobernador Virasoro, y podrían tener un impacto negativo en la salud y el rendimiento de los animales.

Resumo O nematoide-das-galhas Meloidogyne incognita está entre os fatores bióticos que afetaram enormemente a produção e a qualidade da cultura do tomate. O nematoide parasita de ovos, Purpureocillium lilacinum (Pl), é considerado um dos mais promissores agentes no controle e superação desse fitopatógeno. O efeito nematicida do isolado nativo Pl AUMC 10149 na sobrevivência de juvenis de segundo estágio e na eclosão dos ovos de M. incognita em diferentes momentos de exposição foi testado in vitro. Os dados obtidos mostraram que o Pl deu um percentual máximo de mortalidade de J2 (97.6%) e inibição da eclosão dos ovos (79.8%) após 72 horas de exposição. A potencialidade de Pl e de Bio-Nematon para controlar M. incognita infectando tomate foi conduzida em diferentes tempos de aplicação in vivo. Nove tratamentos com cinco repetições foram usados para tais bioagentes em comparação com o nematicida Oxamyl. Cada muda foi inoculada com 1.000 J2s de nematoide / vaso e 10 mL de Pl (1×1010 CFU/mL). Ou suspensão de esporos Bio-Nematon (1×108 CFU/mL) 10mL/pot. Os resultados indicaram que os tratamentos mais eficazes na redução da população de nematoides, número de galhas e desovas de M. incognita nas raízes das plantas foram realizados com Pl pré-plantio e pós-infecção com Pl (Rf 1.9), dando um aumento significativo no comprimento da planta (64.9%), massa fresca (72.52%) e massa seca da parte aérea (163.41%) sem impactar negativamente o meio ambiente. Portanto, o presente estudo confirmou que o uso de P. lilacinum AUMC 10149 pode ser usado como um suplemento prático para o manejo ecologicamente correto de nematoides-das-galhas no Egito.

Abstract Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile’s survival and egg hatching of M. incognita at different times of exposure was tested in vitro. The obtained data showed that Pl gave a maximum percentage of J2 mortality (97.6%) and egg hatching inhibition (79.8%) after 72 hours of exposure. The potentiality of Pl as well as Bio-Nematon to control M. incognita infecting tomato was conducted using different times of application in vivo. Nine treatments with five replicates were used for such bioagents compared with the nematicide Oxamyl. Each seedling was inoculated with 1000 J2s of nematode/pot and 10 mL of Pl (1x1010 CFU/mL) or Bio-Nematon spore suspension (1x108 CFU/mL) 10mL/pot. The results indicated that the most effective treatments in reducing nematode population, number of galls and egg masses of M. incognita in plant roots was performed with treatment by Pl pre-planting and post-infection with Pl (Rf 1.9) giving a significant enhancement in plant length (64.9%), fresh weight (72.52%) and shoot dry weight (163.41%) without negatively impacting environment. Therefore, the present study confirmed that using P. lilacinum AUMC 10149 can be used as a practical supplement to environmentally friendly disease management of root-knot nematodes in Egypt.

Resumo O Brasil é o maior produtor de figos da América do Sul, porém o cultivo comercial brasileiro da figueira baseia-se na plantação de uma única cultivar, o Roxo-de-Valinhos, resultando em sérios problemas relativos a pragas e doenças. Uma vez que há variações epigenéticas na interação planta-patógeno, principalmente por meio da regulação gênica, o presente trabalho objetiva realizar a caracterização in vivo de acessos de figo, por meio da análise de incidência natural de nematoides formadores de galha e de incidência natural de ferrugem, correlacionada ao seu perfil epigenômico, a fim de subsidiar trabalhos de conservação, melhoramento genético e produção da cultura. A análise dos componentes principais dos dados da caracterização dos acessos foi realizada por meio da matriz de correlação residual obtida pela análise de variância conjunta utilizando o programa GENES. Pôde-se constatar que todas as plantas foram atacadas por este patógeno, evidenciando que são suscetíveis ao mesmo. Já a análise conjunta dos dados demonstrou que a metilação e a incidência de ferrugem em folhas, quando observadas na mesma fase fenológica da planta, se correlacionam, apresentando evidências iniciais de mesmas cargas fatoriais de pressão nos genótipos, com a premissa de comportamento semelhante nos mesmos, indicando que, além do fator genético, fatores abióticos também são responsáveis pelas alterações no fenótipo das plantas, evidenciando a plasticidade fenotípica das mesmas.

Abstract Commercial fig tree cultivation in Brazil involves a single cultivar, ‘Roxo-de-Valinhos’. The use of a single cultivar results in serious diseases and related problems. The aim of this study was to characterize fig accessions by analyzing the natural root-knot nematode and leaf rust incidence in relation to the epigenomic profile of the plant, since epigenetic variations affect plant–pathogen interactions. All plants were attacked by nematodes, indicating susceptibility; Meloidogyne incognita was the root-knot nematode species involved. Joint analysis of data showed that methylation and leaf rust incidence were correlated when observed in the same phenological phase, presenting initial evidence of the same factorial pressure loads in genotypes, suggesting similar behavior within these genotypes.

Resumo Nematoides entomopatogênicos (NEP) das famílias Heterorhabditidae e Steinernematidae são amplamente utilizados no controle de insetos-pragas. No Brasil, os estudos relacionados a caracterização e identificação destes entomopatógenos são recentes e escassos. Nesse sentido, o objetivo deste estudo foi isolar NEP de amostras de solos coletadas em diferentes áreas no estado do Paraná, Brasil. Um isolado Heterorhabditis (UEL 08) detectado em amostra de solo em área de pastagem cultivada com braquiária, localizada em Londrina, Paraná, Brasil (23º34´311´´S, 050º58´298´´W), utilizando o método de “inseto-isca” com lagartas de Galleria mellonella. Para a identificação foram realizados estudos de morfometria e identificação molecular a partir da amplificação da região ITS. Algumas diferenças foram encontradas em termos de morfometria em comparação com a descrição original, entretanto, os dados moleculares demonstraram que a sequência obtida para o isolado UEL 08 é idêntica à sequência de referência de H. amazonensis (DQ665222), com a qual apresentou 100% de similaridade. Os estudos das características biológicas de H. amazonensis (UEL 08) revelaram que o isolado tem dois ciclos de vida distintos, um curto (216 h) e outro longo (288 h), sendo que ocorrem duas gerações em ambos os ciclos. O isolado UEL 08 H. amazonensis foi patogénico e virulento sobre os três hospedeiros avaliados. Notadamente, as larvas de G. mellonella e Alphitobius diaperinus foram consideradas mais susceptíveis do que os adultos do percevejo Dichelops (Diacereus) melacanthus, com percentagens de mortalidade de 100%, 85% e 46% de mortalidade, respectivamente. O ensaio de produção in vivo revelou um rendimento médio diário de 3,4 × 103 juvenis infectantes/g de larva hospedeira.

Abstract Entomopathogenic nematodes (EPNs) from Heterorhabditidae and Steinernematidae families are extensively used to control insect pests. In Brazil, however, relatively few studies have identified and characterized these entomopathogens. The objective of this study was to identify and characterize an EPN isolate obtained from soil samples collected in the state of Paraná, Brazil. An isolate (UEL 08) of Heterorhabditis was detected in a soil sample collected from a pasture area cultivated with Brachiaria grass in Londrina, state of Paraná, Brazil (23°34ʹ311ʹʹS, 050°58ʹ298ʹʹW), using the insect-baiting technique with Galleria mellonella larvae as hosts. The nematode was identified through morphometric studies and molecular analyses based on amplification of the rDNA ITS region. Although we identified certain morphometric differences compared with the original description, the molecular data indicated that the ITS sequence obtained for the UEL 08 isolate is identical to the reference sequence of H. amazonensis (DQ665222) and presented 100% similarity. Thus, the findings of our morphological and molecular studies confirmed that the isolated nematode is H. amazonensis, which is the first time this species has been registered in Paraná. Study of the biological characteristics of H. amazonensis (UEL 08) revealed that the isolate has two distinct life cycles – one short (216 h) and the other long (288 h) – and produces two generations in both cycles. We observed that H. amazonensis (UEL 8) was pathogenic and virulent to the three evaluated hosts, although with different virulence against these hosts. The larvae of G. mellonella and Alphitobius diaperinus were more susceptible than adult Dichelops (Diacereus) melacanthus, with 100%, 85%, and 46% mortality, respectively. Furthermore, an in vivo production assay revealed a mean daily yield of 3.4 × 103 infective juveniles/g host larvae.