Schiff bases are diverse organic compounds with an azomethine structure (–C=N–), holding potential in both chemistry and biology. They serve as catalysts, stabilizers, and exhibit various biological activities. The molecular structure of Schiff bases influences their biological properties, including antimicrobial effects. Redox-active compounds with more negative potentials tend to be more effective against microbes. In one of our recent studies, we explored the antimicrobial properties of two Schiff bases derivatives, SB-1 ((E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino) and SB-2 ((E)-2-((4-nitrobenzilidene)amino)aniline). SB-1 showed antibacterial activity against certain Gram-positive bacteria, while SB-2 did not. The difference in their cyclic voltametric profiles, especially SB-1’s more negative reduction potential, prompted us to carry out further characterizations, including scan-rate studies, solvent analysis, and computational calculations. We found that SB-1, which presents a stable intramolecular hydrogen bond, undergoes irreversible oxidation, likely at the –NH2 group, and a quasi-reversible reduction via an intramolecular reductive coupling of the (–C=N–) azomethine group, supported by orbital theoretical calculations. This research sheds light on the potential applications of Schiff bases in antimicrobial contexts, guided by their redox properties and structure. –C=N–, CN –C=N– , C N biology catalysts stabilizers activities effects Redoxactive Redox active microbes studies derivatives SB1 SB 1 SB- E4amino33,5ditertbutyl2hydroxybenzylideneamino E4amino335ditertbutyl2hydroxybenzylideneamino Eaminoditertbutylhydroxybenzylideneamino E 4 amino 3 3,5 di tert butyl 2 hydroxybenzylidene 5 ((E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino SB2 E24nitrobenzilideneaminoaniline. E24nitrobenzilideneaminoaniline Enitrobenzilideneaminoaniline nitrobenzilidene aniline . ((E)-2-((4-nitrobenzilidene)amino)aniline) Grampositive Gram positive bacteria not profiles SB1s SBs s characterizations scanrate scan rate analysis calculations SB1, 1, bond oxidation NH2 NH –NH group quasireversible quasi reversible (–C=N– contexts –C=N E4amino33 5ditertbutyl2hydroxybenzylideneamino ditertbutyl hydroxybenzylideneamino 35 3, nitrobenzilideneaminoaniline ((E)-2-((4-nitrobenzilidene)amino)aniline (–C=N Eamino E4amino3 ditertbutylhydroxybenzylideneamino E4amino

Compared to other species, components of Combretum lanceolatum are still with few data reported in the literature. This work describes the compounds identification, antioxidant and antimicrobial activities of C. lanceolatum twigs. Ethanolic extract (EECLT) from C. lanceolatum twigs was submitted to partition obtaining: hexane (HF), diethyl ether (EEF), ethyl acetate (EAF) and hydromethanolic (HMF) fractions. They were analyzed by gas chromatography-mass spectrometry, high performance liquid chromatography coupled to mass spectrometry and direct insertion mass spectrometry and evaluated for antioxidant assay (2,2-diphenyl-1-picrylhydrazyl (DPPH) method) and antimicrobial assay. Fifty-seven compounds were identified in the fractions. In antioxidant assay, EECLT and EAF demonstrated good antioxidant potential (half maximal effective concentration (EC50): 57.9 and 45.4 µg mL–1, respectively), better than the positive control butylated hydroxytoluene (BHT) (EC50: 69.34 µg mL–1). For antimicrobial assay, all fractions presented promising minimal inhibitory concentration (MIC). EECLT presented the best values against Staphylococcus aureus (125 µg mL–1) and Escherichia coli (62.5 µg mL–1) and better than the positive control fluconazole (8 and 16 µg mL–1) against Candida albicans (3.9 µg mL–1) and Candida krusei (15.6 µg mL–1) strains. This study presents relevant chemical and biological information about C. lanceloatum expanding the knowledge of Brazilian flora. species literature identification C (EECLT obtaining HF, HF , (HF) EEF, EEF (EEF) (EAF HMF (HMF chromatographymass 2,2diphenyl1picrylhydrazyl 22diphenyl1picrylhydrazyl diphenylpicrylhydrazyl 2,2 diphenyl 1 picrylhydrazyl 2 DPPH (DPPH method Fiftyseven Fifty seven half EC50 EC (EC50) 579 57 9 57. 454 45 4 45. mL1 mL mL–1 respectively, respectively respectively) BHT (BHT (EC50 6934 69 34 69.3 mL–1. . MIC. MIC (MIC) 125 (12 62.5 625 62 5 (62. 8 ( 3.9 39 3 (3. 15.6 156 15 6 (15. strains flora (HF (EEF 2diphenyl1picrylhydrazyl 22 2, EC5 mL– (EC5 693 69. (MIC 12 (1 62. (62 3. (3 15. (15 (EC (6

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

Protium ovatum Eng. Burseraceae is an endemic species in Brazil used in traditional medicine. This study investigated the chemical variation and the in vitro antioxidant and antimicrobial properties of dichloromethane soluble fraction of hydrolate (DSFH) from leaves of P. ovatum collected from five different vegetation physiognomies within the Cerrado Goiano. The region was characterized based on the DSFH chemical composition by gas chromatography coupled to mass spectrometry (GC-MS) analysis. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed to compare the different DSFHs from five Savannah regions in Brazil. The DSFHs from the Cerrado stricto sensu (CSS), Mata de Galeria (MG) and Cerradão (C) regions were grouped in the negative part of PC1, showing high similarity. Samples from the C and MG regions showed antioxidant activity of IC50 = 0.98 and 0.78 mg mL-1, respectively, and 0.250 mg mL-1 of butylated hydroxytoluene (positive control). DSFH from different regions exhibited antifungal activity against Candida albicans. The results show that the chemical composition and the biological activity of DSFHs can be affected according to the area of collection. Eng medicine (DSFH P Goiano GCMS GC MS (GC-MS PCA (PCA HCA (HCA CSS, CSS , (CSS) (MG (C PC1 PC similarity IC IC5 098 0 98 0.9 078 78 0.7 mL1, mL1 mL 1, 1 respectively 0250 250 0.25 mL- positive control. control . control) albicans collection (CSS 09 9 0. 07 7 025 25 0.2 02 2

A series of novel thieno[2,3-d]pyrimidine derivatives were designed, synthesized and evaluated for their biological ability. 2-Amino-4,7-dihydro-5H-thieno[2,3-d]pyrano-3-cyanonitrile was synthesized by Gewald reaction using pyranone as substrate, malonitrile and sulfur powder as raw materials and triethylamine as base at room temperature. Subsequent amination with N,N-dimethylformamide dimethyl acetal (DMF-DMA) gave N'-(3-cyano-4,7-dihydro-5H-thieno[2,3-c]pyran-2-yl)-N,N-dimethylmethanimidamide. In this article, the 23 thieno[2,3-d] pyrimidines were obtained by Dimroth rearrangement condensation with different anilines, 16 of them being new compounds. Meanwhile, all compounds were assessed for breast cancer MDA-MB-231 cell line bioactivity with paclitaxel (PTX) as the positive control, and all compounds in the series showed inhibitory effects on breast cancer cell MDA-MB-231. The IC50 of compound l against MDA-MB-231 is 27.6 μM, which is similar to that of PTX with an IC50 of 29.3 μM. This means that compound l exhibits comparable inhibitory activity to PTX in MDA-MB-231 cells and may be considered as a potential anti-MDA-MB-231 inhibitor. thieno2,3dpyrimidine thieno23dpyrimidine thienodpyrimidine thieno 2,3 d pyrimidine 2 3 designed ability 2Amino4,7dihydro5Hthieno2,3dpyrano3cyanonitrile 2Amino47dihydro5Hthieno23dpyrano3cyanonitrile AminodihydroHthienodpyranocyanonitrile Amino 4,7 dihydro 5H pyrano cyanonitrile 4 7 H substrate temperature N,Ndimethylformamide NNdimethylformamide N,N dimethylformamide N DMFDMA DMF DMA (DMF-DMA N3cyano4,7dihydro5Hthieno2,3cpyran2ylN,Ndimethylmethanimidamide. N3cyano47dihydro5Hthieno23cpyran2ylNNdimethylmethanimidamide NcyanodihydroHthienocpyranylNNdimethylmethanimidamide cyano c pyran yl dimethylmethanimidamide. dimethylmethanimidamide N'-(3-cyano-4,7-dihydro-5H-thieno[2,3-c]pyran-2-yl)-N,N-dimethylmethanimidamide article thieno2,3d thieno23d thienod thieno[2,3-d anilines 1 Meanwhile MDAMB231 MDAMB MDA MB 231 MDA-MB-23 (PTX control MDAMB231. 231. IC IC5 276 27 6 27. μM 293 29 29. antiMDAMB231 antiMDAMB anti anti-MDA-MB-23 inhibitor thieno2 3dpyrimidine dpyrimidine 2, 2Amino4 7dihydro5Hthieno2 3dpyrano3cyanonitrile Hthieno dpyrano 47 4, Ndimethylformamide NN N3cyano4 3cpyran2ylN Ndimethylmethanimidamide cpyran ylN N3cyano4,7dihydro5Hthieno2,3cpyran2ylN,Ndimethylmethanimidamide ylNNdimethylmethanimidamide 3d MDAMB23 MDA-MB-2 antiMDAMB23 anti-MDA-MB-2 2Amino dihydroHthieno 7dihydro5Hthieno dpyranocyanonitrile Ncyano N3cyano cpyranylN MDAMB2 MDA-MB- antiMDAMB2 anti-MDA-MB- MDA-MB anti-MDA-MB

Abstract Introduction. Endophytic fungi (EF) in grapevines (Vitis vinifera) have great potential for agricultural applications and may represent possible biological control agents for vineyards. Objective. To isolate and identify endophytic fungi (EF) from grapevine plants with antibiosis capacity against Botrytis cinerea. Materials and methods. Young and mature branches from forty healthy grapevine plants were collected from seven production lots in the Cañete province, Lima, Peru, during March to May 2022. EF isolation was performed on 702 sections of disinfected tissues using potato dextrose agar (PDA) culture medium, and identification was carried out at the genus level. Secondary metabolites were extracted from twenty-eight EF strains to determine the mycelial inhibition of the pathogen. An analysis of variance (ANOVA) was conducted on the evaluated parameters using the Minitab statistical program. Results. A total of 129 EF strains were isolated from leaves and stems of young and mature grapevine branches, encompassing seven genera (Trichoderma, Aspergillus, Alternaria, Cladosporium, Fusarium, Nigrospora, and Stemphylium). The highest frequency was found in leaves and mature branches. Trichoderma and Alternaria were the most frecuent genera in grapevine plants, with 22.48 % and 21.71%, respectively. Metabolites obtained from the EFVH-01 strain of the genus Cladosporium, and EF-99 and EF-70 strains of the genus Alternaria, had the greatest effect on mycelial inhibition of the pathogen. Conclusions. Strains of endophytic fungi from the genera Cladosporium and Alternaria showed antibiosis capacity against Botrytis cinerea at the laboratory scale, which could potential biocontrol agents of pathogens in grapevine cultivation.

Resumen Introducción. Los hongos endófitos (HE) de la vid (Vitis vinifera) tienen un gran potencial de aplicación en la agricultura y pueden representar posibles agentes de control biológico de los viñedos. Objetivo. Aislar e identificar los hongos endófitos (HE) de plantas de vid con capacidad de antibiosis hacia Botrytis cinerea. Materiales y métodos. Se colectaron ramas jóvenes y maduras de cuarenta plantas sanas de vid de siete lotes de producción en la provincia de Cañete, Lima, Perú, durante los meses de marzo a mayo 2022. El aislamiento de HE se realizó de 702 secciones de tejidos desinfectados en medio de cultivo papa dextrosa agar (PDA) y la identificación fue a nivel de género. Se extrajeron metabolitos secundarios de veintiocho cepas de HE para determinar la inhibición micelial del patógeno. Se llevó a cabo un análisis de varianza (ANDEVA) de los parámetros evaluados con el programa estadístico Minitab. Resultados. Se aislaron un total de 129 cepas de HE de hojas y tallos de ramas jóvenes y maduras de vid, que correspondieron a siete géneros (Trichoderma, Aspergillus, Alternaria, Cladosporium, Fusarium, Nigrospora y Stemphylium). La mayor frecuencia se presentó en las hojas y rama madura. Trichoderma y Alternaria fueron los géneros más frecuentes en las plantas de vid con 22,48 % y 21,71 %, respectivamente. Los metabolitos obtenidos de las cepas HEVH-01 del género Cladosporium, HEV-99 y HEV-70 del género Alternaria, tuvieron mayor efecto en la inhibición micelial del patógeno. Conclusiones. Cepas de hongos endofitos del género Cladosporium y Alternaria mostraron capacidad de antibiosis hacia Botrytis cinerea a escala de laboratorio, los cuales podrían ser potenciales biocontroladores de patógenos en el cultivo de vid.

Abstract Introduction. “Green mold,” caused by Penicillium digitatum is one of the phytosanitary issues that limits citrus production. For its control, synthetic fungicides are used, which have lost effectiveness due to resistance developed by the fungus. An alternative is the use of endophytic fungi with biocontrol action. Objective. To evaluate the effect of secondary metabolites (SM) from endophytic fungi (EF) on the mycelial inhibition of Penicillium digitatum and the effectiveness of disease control in mandarin fruits (Citrus reticulata) post-harvest. Materials and methods. The study was conducted in 2022, using a completely randomized experimental design in the Plant Health Laboratory at the Universidad Nacional de Cañete (UNDC), Lima, Peru. For the antibiosis test, secondary metabolites were extracted from ten strains of EF from the genera Trichoderma sp., Fusarium sp., and Aspergillus sp., where mycelial inhibition of the pathogen (%) was evaluated. SMs were sprayed at 15 % (v/v) concentration on mandarin fruits that were disinfected and inoculated with the pathogen by spraying (1x 105 CFU/cc). Additionally, a commercial biocontrol, a vegetable oil, and a fungicide were used. After 6 and 9 days, disease incidence (%) and severity index (0, 1, 2, 3) were evaluated. Results. Secondary metabolites from strains the HEA-111 (Aspergillus), HEA-109 (Fusarium), and HSA-1 (Trichoderma) showed the highest mycelial inhibition with 95.05 %, 87.51 %, and 47.47 %, respectively. In mandarin fruits treated with SMs from strains HEA-109 and HSA-1, there was a control of 80 % and 55 %, respectively. Conclusions. SMs from EF were effective in inhibiting the mycelial growth of P. digitatum and reduces disease progression in mandarin fruits post-harvest.

Resumen Introducción. El “moho verde” causado por Penicillium digitatum es uno de los problemas fitosanitarios que limita la producción en los cítricos. Para su control se utilizan fungicidas sintéticos, que han perdido eficacia, debido a la resistencia generada por el hongo. Una alternativa, es el uso de hongos endófitos con acción biocontroladora. Objetivo. Evaluar el efecto de metabolitos secundarios (MS) de hongos endófitos (HE) en la inhibición micelial de Penicillium digitatum y la eficacia de control de la enfermedad, en frutos de mandarina (Citrus reticulata) después de la cosecha. Materiales y métodos. El estudio se realizó en 2022, bajo un diseño experimental completo al azar, en el laboratorio de Sanidad Vegetal, Universidad Nacional de Cañete (UNDC), Lima, Perú. Para la prueba de antibiosis se extrajeron los metabolitos secundarios de diez cepas de HE de los géneros Trichoderma sp., Fusarium sp. y Aspergillus sp., en donde se evaluó la inhibición micelial del patógeno (%). Se asperjaron MS a una concentración del 15 % (v/v) sobre frutos de mandarina que fueron desinfectados e inoculados con el patógeno por aspersión (1x105 UFC/cc). Adicionalmente, se utilizaron un biocontrol comercial, un aceite vegetal y un fungicida. Después de 6 y 9 días, se evaluaron la incidencia (%) y el índice de severidad (0,1,2,3) de la enfermedad. Resultados. Los metabolitos secundarios de las cepas HEA-111 (Aspergillus), HEA-109 (Fusarium) y HSA-1 (Trichoderma) presentaron la mayor inhibición micelial con 95,05 %, 87,51 % y 47,47 %, respectivamente. En los frutos de mandarina tratados con los MS de las cepas HEA-109 y HSA-1, hubo un control del 80 % y 55 %, respectivamente. Conclusiones. Los MS de HE tuvieron efecto en la inhibición micelial de P. digitatum y redujeron el avance de la enfermedad en frutos de mandarina después de la cosecha.

Abstract Introduction. Supply chain issues have increased the costs of raw material and reduced the availability of materials for the production of biological control agents. This can result in greater disease pressure and lower yields on farms. Objective. To determine the effect of different amounts of starch and the use of local ingredients in small- and large-scale fermentation processes for Trichoderma harzianum. Materials and methods. The study was conducted in San José, Costa Rica, between 2016 and 2018. Flask experiments were performed to investigate the reduction or elimination of starch in commercial fermentation media. Fermentation vessel trials were conducted to evaluate the effectiveness of an alternative local medium, which included three treatments: 1) commercial medium as a control, 2) 10 % molasses medium, and 3) 10 % molasses with 0.5% yeast extract. Viable spore counts were performed to determine colony-forming units (CFU/mL). Results. Reducing starch to 10 % of the original medium had no impact on CFU/mL. However, the absence of starch resulted in uneven growth during fermentation. Molasses produced approximately half the CFU/mL compared to the commercial medium but exceeded the threshold of 107 CFU/mL used in studies for the biological control of plant pathogens. Results obtained in a commercial-scale fermenter were similar to those of pilot-scale fermentation. Conclusion. Reducing starch content in the commercial medium did not affect growth, but the absence of starch led to solid mycelium clumps. The use of a local molasses-based medium on a commercial scale feasible as long as the required viable spore count for field use is maintained.

Resumen Introducción. Los problemas en la cadena de suministro aumentaron los costos de las materias primas y redujeron la disponibilidad de materiales para la producción de agentes de control biológico. Esto puede ejercer mayor presión de enfermedades y menores rendimientos en las granjas. Objetivo. Determinar el efecto de diferentes cantidades de almidón y el uso de ingredientes locales en procesos de fermentación a pequeña y gran escala para Trichoderma harzianum. Materiales y métodos. El estudio se ralizó en San José, Costa Rica, entre 2016 y 2018. Se realizaron ensayos en matraces para investigar la reducción o eliminación de almidón en medios de fermentación comerciales. Se llevaron a cabo ensayos en recipientes de fermentación para evaluar la efectividad de un medio local alternativo, que incluyó tres tratamientos: 1) medio comercial como control, 2) melaza al 10 % y 3) melaza al 10 % con 0,5 % de extracto de levadura. Se realizaron recuentos de esporas viables para determinar las unidades formadoras de colonias (UFC/mL). Resultados. La reducción de almidón al 10 % del medio original no tuvo impacto en las UFC/mL. Sin embargo, la ausencia de almidón resultó en un crecimiento desigual durante la fermentación. La melaza produjo aproximadamente la mitad de las UFC/mL en comparación con el medio comercial, pero superó el umbral de 107 UFC/mL utilizado en estudios para el control biológico de patógenos de plantas. Los resultados obtenidos en un fermentador a escala comercial fueron similares a los de la fermentación a escala piloto. Conclusión. La reducción del contenido de almidón en el medio comercial no afectó al crecimiento, pero la ausencia de almidón provocó acumulaciones sólidas de micelio. El uso de un medio de melaza de origen local a escala comercial parece factible mientras se mantenga un recuento de esporas viables requeridas para su uso en el campo.

Abstract Introduction. Paraguay is the sixth largest producer and third largest exporter of soybeans (Glycine max (L.) Merr.) in the world and this crop is the most important socio-economic crop in the country. However, its productivity can be adversely affected by diseases caused by phytopathogenic fungi. In addition, phytosanitary information on soybean cultivation in Paraguay is limited. Objective. To understand farmers’ perceptions of the main soybean diseases and their management. Materials and methods. Between April and May 2022, a questionnaire in Google Forms format with open and closed-ended multiple-choice questions, was applied to 45 soybean producers aged between 30 and 50 years, who cultivate in areas between 200 to 1000 ha in the departments of Alto Paraná, Itapúa, and Caaguazú in Paraguay. Results. Among the respondents, 56% considered Asian soybean rust (Phakopsora pachyrhizi) as the most significant phytosanitary problem associated with soybean cultivation, followed by late-season diseases (LSD) such as brown spot (Septoria glycines) and frogeye leaf spot (Cercospora kikuchii). Respondents indicated taht they use three to four fungicide applications as a disease control measure, with their choice based on the type of product formulation. A majority of respondents noted that both the cost and frequency of applications increased over time. Additionally, 53% mentioned that biological fungicides are a viable alternative for integrated disease management. Conclusion. The responses obtained in this research allowed obtaining the perception of disease management tactics of soybean producers in Paraguay, underscoring the significance of Asian soybean rust and late-season diseases. However, there is a need for further research that can explore all aspects of pathogen management.

Resumen Introducción. Paraguay es el sexto productor y tercer exportador mundial de soja (Glycine max (L.) Merr.), este cultivo es el de mayor importancia socioeconómica en el país. Sin embargo, su productividad puede verse afectada por enfermedades causadas por hongos fitopatógenos. Además, la información fitosanitaria sobre el cultivo de soja en Paraguay es limitada. Objetivo. Comprender la percepción de agricultores sobre las principales enfermedades de la soja y su manejo. Materiales y Métodos. Entre abril y mayo de 2022, se aplicó un cuestionario en formato de formularios de Google con preguntas abiertas y cerradas de selección múltiple a 45 productores de soja de entre 30 y 50 años, quienes cultivan en superficies de entre 200 y 1000 ha en los departamentos de Alto Paraná, Itapúa y Caaguazú en Paraguay. Resultados. El 56 % de los encuestados consideró que el mayor problema fitosanitario asociado al cultivo es la roya asiática de la soja (RAS) (Phakopsora pachyrhizi), seguida por las enfermedades de final de ciclo (EFC), como la mancha marrón (Septoria glycines) y mancha ojo de rana (Cercospora kikuchii). Los entrevistados indicaron que utilizan de tres a cuatro aplicaciones de fungicidas como medida de control de enfermedades, su elección fue basada en el tipo de formulación de los productos. En su mayoría, los entrevistados señalaron que el costo y la cantidad de aplicaciones aumentó con el transcurso del tiempo. El 53 % mencionó que los fungicidas biológicos son una buena alternativa para el manejo integrado de enfermedades. Conclusión. Las respuestas obtenidas en esta investigación permitieron obtener la percepción de las tácticas de manejo de enfermedades de los productores de soja en Paraguay, lo que resaltó la importancia de la RAS y las EFC. No obstante, resulta necesario que se realicen más investigaciones que puedan explorar todos los aspectos del manejo de los patógenos.

Summary: The use of rhizobacteria has the ability to colonize the root system, promote plant growth and biocontrol or suppress phytopathogenic fungi. The objective of this research was to select and analyze fluorescent rhizobacteria solubilizing nitrogen, phosphorus and potassium, producing lytic enzymes with antagonistic activity towards P. palmivora and L. theobromae. The bacteria were isolated from root and leaf tissue of endemic CCN-51 cacao cultivars from the provinces of Los Ríos, Santa Elena and Esmeralda. Characterization of antagonistic activity was based on the selection of proteolytic activity, siderophore production and fluorescent pigmentation under ultra violet light. In addition, antagonistic activity was performed using cell extracts. Nine bacterial strains (BF 567, FZ 9-7, LH 5-10, MH 4-20, MN 5-20, MN 5-19, AC3, PV-25) with protease production, siderophore production and fluorescence emission were selected. The ability of the bacteria to solubilize complex minerals (nitrogen, phosphorus and potassium) was analyzed and their solubilization efficiency varied, ranging from 50 to 100 %. The antagonistic factor of cell supernatants from FZ 9-7, BF 567 and PV-25 inhibited mycelial growth toward P. palmivora and L. theobromae by 40, 60 and 85%, respectively. The use of rhizobacteria could be used as an alternative biofertilizer to chemical fertilizers and biological control of phytopathogenic soil fungi through their volatile emissions.

Resumen: El empleo de rizobacterias tiene la capacidad de colonizar el sistema radicular, promover el crecimiento en plantas y la capacidad biocontroladora o suprimir hongos fitopatógenos. El objetivo de esta investigación fue seleccionar y analizar las rizobacterias fluorescentes solubilizadoras de nitrógeno, fósforo y potasio, productoras de enzimas líticas de actividad antagonistas hacia P. palmivora y L. theobromae. Las bacterias se aislaron del tejido radicular y foliar de cultivares endémicos de cacao CCN-51 de las provincias de Los Ríos, Santa Elena y Esmeralda. La caracterización de la actividad antagonista se apoyó en la selección de actividad proteolítica, producción de sideróforos y pigmentación fluorescente bajo luz ultra violeta. Además, se realizó la actividad antagonista mediante los extractos celulares. Se seleccionaron nueve cepas bacterianas (BF 567, FZ 9-7, LH 5-10, MH 4-20, MN 5-20, MN 5-19, AC3, PV-25) con producción de proteasa, sideróforos y emisión de fluorescencia. Se analizó la capacidad de las bacterias para solubilizar minerales complejos (nitrógeno, fosforo y potasio) su eficiencia de solubilización vario, oscilando entre 50 y 100%. El factor antagónico de los sobrenadantes celulares de FZ 9-7, BF 567 y PV-25 inhiben el crecimiento del micelio hacia P. palmivora y L. theobromae en un 40, 60 y 85%, respectivamente. La utilización de las rizobacterias podría usarse como biofertilizante alternativo a los fertilizantes químicos y control biológico de hongos fitopatógenos del suelo a través de sus emisiones volátiles.

Summary: The cocoa crop is very susceptible to nutritional deficiencies and moniliasis caused by the phytopathogen Moniliophthora roreri. One of the alternatives to synthetic chemicals are compounds based on silicon (Si). In the present investigation, the ef fect of silicon as a biostimulant in cocoa cultivation and as a biological control agent for M. roreri was evaluated. In the experiment, five Si treatments were used: T1 (4.00 kg ha-1), T2 (3.00 kg ha-1), T3 (2.00 kg ha-1) and T4 (1.5 kg ha-1) and a control treatment (without application). Production indicators, ear number, fresh and dry weight of almonds, dry weight of 100 almonds and crop yield were determined. In addition, the incidence and severity of the disease at 60, 120 and 180 days af ter the application of Si and the ef ficiency of the treatments. The significantly higher results for the variables: Production, ear number, fresh and dry weight of almond and dry weight of 100 almonds, were obtained by applying 4 kg ha-1 of Si, all doses of Si exceeded the control (P ≤ 0.05) in the variables related to production. In the control of the phytopathogen (M. roreri), the dose of 4 kg ha-1 Si decreased the incidence and severity of the disease by more than 50%. The application of Si can be an option in cocoa cultivation as a biostimulant and biological control agent for M. roreri.

Resumen: El cultivo del cacao es muy susceptible a deficiencias nutrimentales y a la moniliasis ocasionada por el fitopatógeno Moniliophthora roreri. Una de las alternativas a los productos químicos sintéticos son los compuestos a base de silicio (Si). En la presente investigación se evaluó el efecto del silicio como bioestimulante en el cultivo de cacao y agente de control biológico de M. roreri. En el experimento se utilizaron cincos tratamientos de Si: T1 (4.00 kg ha-1), T2 (3.00 kg ha-1), T3 (2.00 kg ha-1) y T4 (1.5 kg ha-1) y un tratamiento control (sin aplicación). Se determinaron los indicadores de producción, número de mazorca, peso fresco y seco de almendras, peso seco de 100 almendras y el rendimiento del cultivo. Además, de la incidencia y severidad de la enfermedad a los 60, 120 y 180 días después de la aplicación del Si y la eficiencia de los tratamientos. Los resultados significativamente superiores para las variables: Producción, número mazorca, peso fresco y seco de almendra y peso seco de 100 almendra, se obtuvieron mediante la aplicación de 4 kg ha-1 de Si, todas las dosis de Si superaron al control (P ≤ 0.05) en las variables relacionas a la producción. En el control del fitopatógeno (M. roreri), la dosis de 4 kg ha-1 Si disminuyó la incidencia y la severidad de la enfermedad en más del 50%. La aplicación de Si puede ser una opción en el cultivo de cacao como bioestimulante y agente de control biológico de M. roreri.

Resumen El objetivo de este trabajo fue evaluar el efecto combinado de dos tácticas de biocontrol de plagas: la biofumigación con Brassicajuncea y la inoculación de Trichoderma harzianum, sobre el crecimiento in vitro del patógeno Phomopsis spp., agente etiológico de la cancrosis en el cultivo de pecán (Carya illinoinensis). Se trituraron plantas de B. juncea y se colocaron en envases de poliestireno en dosis de 10 y 30 g. Luego, en cada uno de estos recipientes se introdujo una caja de Petri con un disco con micelio dePhomopsis spp. o T. harzianum o ambos hongos (cultivo dual). Se incubó en cámara de cultivo. Los parámetros evaluados fueron la superficie de las colonias y el porcentaje de inhibición miceliar de Phomopsis spp. Los datos se analizaron con estadística no paramétrica mediante la prueba de Kruskal-Wallis. Se obtuvieron los siguientes resultados: i) B. juncea no afectó el crecimiento de T. harzianum; ii) la dosis de 30 g de B. juncea suprimió completamente el crecimiento de Phomopsis spp.; iii) T. harzianum inhibió significativamente el crecimiento de las colonias de Phomopsis spp.; iv) la combinación de T. harzianum y la biofumigación con 10 g de B. juncea mostró sinergia sobre el control del crecimiento de Phomopsis spp. La biofumigación con B. juncea, la aplicación de T. harzianum y la combinación de ambas técnicas podrían ser alternativas promisorias para el control biológico de Phomopsis spp.

Abstract This work aimed to evaluate the combined effect of two pest biocontrol strategies: biofumigation with Brassica juncea and inoculation of Trichoderma harzianum, on the in vitro growth of the pathogen Phomopsis spp., an etiological agent of canker disease in pecan crops (Carya illinoinensis). B. juncea plants were crushed and placed in polystyrene recipients in doses of 10 and 30 g. Then, a Petri dish was introduced to each recipient, with a disk with a grown mycelium of Phomopsis spp. or T. harzianum, or both fungi (dual culture). Treatments were incubated in a culture chamber. The parameters evaluated were colonies’ surface area and percentage of mycelial inhibition of Phomopsis spp. Data were analyzed with non-parametric statistics using the Kruskal-Wallis test. The results indicated that: i) B. juncea did not affect the growth of T. harzianum; ii) the 30 g dose of B. juncea completely suppressed the growth of Phomopsis spp.; iii) T. harzianum significantly inhibited the growth of Phomopsis spp. colonies; iv) the combination of T. harzianum and biofumigation with 10 g of B. juncea showed synergy on the growth control of Phomopsis spp. Biofumigation with B. juncea, the application of T. harzianum, and the combination of both techniques could be promising alternatives for the biological control of Phomopsis spp.

ABSTRACT Colombia is the ninth largest producer of dragon fruit in the world and the department of Boyacá is the largest with 440 hectares planted. Bacterial phytopathogens can cause pitahaya fruit losses and low yields by producing stem soft rot. This research aimed to study and identified possible agents of bacterial diseases of pitahaya in Boyacá, Colombia. Thirteen farms in the region were selected to take 20 samples by means of a targeted and random sampling of stem and fruit tissues with soft rot symptoms in the early stages of the disease. A process of microbiological isolation, biochemical and molecular taxonomic identification of the isolated bacteria. The 16s rRNA gene sequences of the V2-V5 region were edited by removing the primers, assembling and obtaining the consensus sequence of the primers 1100R-337F and 800R -518F. The phylogenetic analysis was performed by BLAST at NCBI, using the "Classifier" and "SeqMatch" tools from the RDP website, and phylogenetic trees were created by multiple alignment using the MUSCLE algorithm and the Tamura Nei distance method was performed. Signs like blisters and mucilaginous fluids, symptoms like yellow and brown chlorotic spots, soft rot, and liquefaction were identified, and possible vectors like flies and ants were report. Twenty-five bacterial morphotypes were identified classifieds in 4 phyla, 9 families and 13 genera. The analysis of the 16S rRNA gene sequences of the bacterial strains showed a 98 to 100% identity with Enterobacter cloacae, Pectobacterium carotovora and Paenibacillus glucanolyticus, reported in other studies as causing the soft rot of the pitahaya stem and fruit. New species were reported as possible pathogenic bacteria of pitahaya: Pantoea cypripedii, Kluyvera intermedia and Klebsiella oxytoca. Infectivity assays did not have positive results. The microbiota identified in the stages of the necrotrophic phase or final stage of soft rot of the stem belong to the genera Achromobacter, Sphingobacterium, Pseudomonas, Klebsiella, Paenibacillus, Bacillus, Stenotrophomonas and Microbacterium. In the fly Leptoglossus zonatus associated with the crop were identified Pseudomonas fulva and Lysinibacillus fusiformis were identified. This is also the first official report of a complex of possible phytopathogen bacteria of the order Enterobacterales (Enterobacteriacea, Erwiniaceae and Pectobacteriaceae family) in symptoms by bacterial disease on pitahaya Colombian crops. Identification of the bacteria in a pathogenic system can guide chemical and biological control practices in order to increase the productive and export potential of exotic and orphan crops from small local farmings.

RESUMEN Colombia es el noveno productor de pitahaya amarilla en el mundo y el Departamento de Boyacá es el mayor productor con 440 hectáreas plantadas. Los fitopatógenos bacterianos pueden causar pérdidas de frutos de pitahaya y bajos rendimientos al producir la pudrición blanda de los tallos. El objetivo de esta investigación fue estudiar e identificar posibles agentes de enfermedades bacterianas de la pitahaya en Boyacá, Colombia. Trece (13) fincas de la región fueron seleccionadas para la toma de 20 muestras mediante un muestreo dirigido y al azar de tejidos de tallo y frutos con síntomas de pudrición blanda en estadios iniciales de la enfermedad. Se realizó un proceso de aislamiento microbiológico, identificación bioquímica y taxonómica molecular de las bacterias aisladas. Las secuencias del gen ARNr 16s de la región V2-V5 fueron editadas mediante la eliminación de los primers, ensamblaje y obtención de la secuencia consenso de los primers 1100R-337F y 800R -518F. El análisis filogenético fue hecho por BLAST en el NCBI, por las herramientas "Classifier" y "SeqMatch", del sitio Web del RDP y se realizaron árboles filogenéticos mediante alineamiento múltiple usando el algoritmo MUSCLE y el método de distancias de Tamura Nei. Se registraron signos como ampollas y fluidos mucilaginosos, síntomas como manchas cloróticas amarillas y marrones, pudrición blanda y licuefacción, y se reportaron posibles vectores como moscas y hormigas. Veinticinco (25) morfotipos de bacterias fueron clasificados en 4 filos, 8 familias y 13 géneros. El análisis de las secuencias del gen ARNr 16S de las cepas bacterianas mostró una identidad del 98 al 100% con Enterobacter cloacae, Pectobacterium carotovora y Paenibacillus glucanolyticus, reportados en otros estudios como causantes de la pudrición blanda del tallo y fruto de pitahaya. Se reportaron nuevas especies como posibles bacterias patógenas de pitahaya: Pantoea cypripedii, Kluyvera intermedia y Klebsiella oxytoca. Los ensayos de infectividad no arrojaron resultados positivos. La microbiota identificada en los estadios de la fase necrotrofa o final de la pudrición blanda del tallo podría estar conformada por los géneros Achromobacter, Sphingobacterium, Pseudomonas, Klebsiella, Paenibacillus, Bacillus, Stenotrophomonas y Microbacterium. En la mosca Leptoglossus zonatus asociada al cultivo se identificó Pseudomonas fulva y Lysinibacillus fusiformis. Este es el primer registro oficial de un complejo de posibles bacterias fitopatógenas del orden Enterobacterales (familia Enterobacteriaceae, Erwiniaceae y Pectobacteriaceae) en síntomas por enfermedad bacteriana en cultivos colombianos de pitahaya. La identificación de las bacterias de un pato-sistema puede orientar las prácticas de control químico y biológico con el fin de incrementar el potencial productivo y de exportación de los cultivos exóticos y huérfanos de las pequeñas fincas locales.

Abstract Ovine Enzootic Abortion (OEA) is caused by Chlamydia abortus and has recently been recognized as endemic in Mexico. Due to the impact of OEA on intensive lamb production, it is necessary to establish a sanitary control plan based on an efficient diagnosis. The loop-mediated isothermal amplification technique (LAMP) is a molecular test that can specifically identify C. abortus. The aim of this study was to standardize the LAMP technique for the specific detection of C. abortus in ovine vaginal exudates. Primers were identified and modified from an electronic database. The effective conditions of the technique were determined using synthetic DNA and positive biological samples by PCR as references. The assay detection limit was 1 × 10-5 of genetic material, equivalent to 8.5 copies. The standardized LAMP test is proposed as a novel molecular tool for the rapid and specific diagnosis of C. abortus infection from ovine vaginal exudate samples in Mexico.

Resumen El Aborto Enzoótico Ovino (AEO) es causado por Chlamydia abortus y ha sido reconocido recientemente como endémico en México. Debido al impacto del AEO en la producción intensiva de corderos, es necesario establecer un plan de control sanitario basado en un diagnóstico eficiente. La técnica de amplificación isotérmica mediada por bucle (LAMP) es una prueba molecular que puede identificar específicamente a C. abortus. El objetivo de este estudio fue estandarizar la técnica de LAMP para la detección específica de C. abortus a partir de exudado vaginal ovino. Los cebadores fueron identificados y modificados a partir de una base de datos electrónica. Las condiciones efectivas de la técnica se determinaron con ADN sintético y de muestras biológicas positivas por PCR como referencia. El límite de detección de la prueba fue de 1 × 10-5 de material genético, equivalente a 8.5 copias. Se propone el test de LAMP estandarizado como una nueva herramienta molecular para el diagnóstico rápido y específico de la infección por C. abortus a partir de muestras de exudado vaginal ovino en México.

Research that directs the way stakeholders act and how they collaborate is essential when addressing complex environmental challenges in the field of sustainability science. For example, researchers attempting to manage Prosopis invasions through biological control in South Africa have historically faced challenges from stakeholders. In this study we illustrate the importance of stakeholder engagement and social learning by outlining the collaborative efforts of various stakeholders to promote effective, integrative and sustainable management of Prosopis invasions in the Northern Cape, South Africa. Through a community of practice approach, stakeholders worked together over the past half-decade in an attempt to develop a National Strategy for Prosopis management and improve its control. This strategy aimed not only to emphasise the need for integration of biomass use (aimed at offsetting the costs of mechanical clearing and necessary herbicide use) but also to underscore the significance of biocontrol alongside other management approaches. Stakeholders also identified that adequate farm-scale planning is necessary to provide a sense of purpose and assist in monitoring of progress. We worked alongside land managers and experts to develop such plans. The engagement of local champions played a crucial role in facilitating collaboration and learning among stakeholders, emphasising the significance of inclusive approaches in addressing complex sustainability challenges. In addition, we gained an understanding of how to develop the community of practice to enhance collaboration that ensures the implementation of plans to better manage Prosopis. Our findings underscore the necessity of meaningful stakeholder engagement and collaboration in effective invasive species management. By promoting understanding and involvement of diverse stakeholders, initiatives can have a greater impact in addressing broader sustainability issues. SIGNIFICANCE: Our findings highlight the fundamental role of stakeholder collaboration in addressing environmental challenges (e.g. biological invasions), promoting sustainability and fostering social learning. Collaboration facilitates exchange of knowledge, promotes social learning and allows stakeholders to make informed decisions when addressing sustainability issues. Collaborative approaches promote the effectiveness of a community of practice in managing Prosopis invasions in South Africa. Local champions played a pivotal role in facilitating collaboration, bridging communication gaps and promoting inclusive approaches. Sustained stakeholder engagement, transdisciplinary collaborations, effective biological control and market development for biomass products will be essential to improve the sustainable management Prosopis.