http://sedici.unlp.edu.ar:80/handle/10915/66164 2026-04-11T11:14:55Z 2026-04-11T11:14:55Z Gallo, Micaela Belén Torres Nicolini, Andrés Martínez, Sergio Iván Perelló, Analía Edith Álvarez, Vera Alejandra Consolo, Verónica Fabiana http://sedici.unlp.edu.ar:80/handle/10915/189488 2025-12-27T04:29:35Z 2025-12-01T00:00:00Z

Articulo Nanopartículas de óxido de cobre biogénicas de Trichoderma harzianum: un nuevo enfoque para el manejo del brusone del trigo Mundo Nano; vol. 19, no. 37 Wheat blast, caused by the fungus Pyricularia oryzae Triticum pathotype (PoT), is a devastating disease in South America, Asia and Africa due to limited fungicide effectiveness and a lack of resistant varieties. More recently, it has also been detected in Africa, further exacerbating the global threat posed by this pathogen. In Argentina, it has been detected since 2012, but although no outbreaks have yet been recorded, this pathogen represents an imminent risk due to its presence in the nearby countries. For that, new strategies should be considered for controlling the disease and proper surveillance. Nanotechnology can contribute to protecting crops since it offers different mechanisms of action against pathogens. Thus, metallic oxide nanoparticles obtained by physicochemical or biogenic methods can act as antimicrobials. This study involved the biosynthesis of green copper oxide nanoparticles (CuONPs) from the fungus Trichoderma harzianum and evaluation of their ability to reduce fungal mycelium growth and wheat blast disease symptoms in plants. Physicochemical characterization of the CuONPs performed by TEM and EDS showed elongated fibers in shape and an average size of 397 ± 55 nm in length and 124 ± 13 nm in width, as good physico-chemical stability. In vitro and in vivo experiments to evaluate the potential of CuONPs against PoT showed that they were effective in strongly inhibiting the mycelial growth of PoT native aggressive strains PY15, PY22 and PY34 by 74, 72 and 67% respectively, at a concentrationof 1000 ppm. Moreover, CuONPs at a concentration of 500 ppm applied as a foliar spray on wheat plants inoculated with PY34 caused a reduction of 95% in disease severity. Further, wheat plants in which their seeds were previously pelletized with 500 ppm CuONPs showed a disease symptom reduction of 90%. These findings confirm that the biosynthesized CuONPs have a promising antifungal activity, which could be used as protection of wheat against PoT pathogen.

2025-12-01T00:00:00Z Wheat blast, caused by the fungus Pyricularia oryzae Triticum pathotype (PoT), is a devastating disease in South America, Asia and Africa due to limited fungicide effectiveness and a lack of resistant varieties. More recently, it has also been detected in Africa, further exacerbating the global threat posed by this pathogen. In Argentina, it has been detected since 2012, but although no outbreaks have yet been recorded, this pathogen represents an imminent risk due to its presence in the nearby countries. For that, new strategies should be considered for controlling the disease and proper surveillance. Nanotechnology can contribute to protecting crops since it offers different mechanisms of action against pathogens. Thus, metallic oxide nanoparticles obtained by physicochemical or biogenic methods can act as antimicrobials. This study involved the biosynthesis of green copper oxide nanoparticles (CuONPs) from the fungus Trichoderma harzianum and evaluation of their ability to reduce fungal mycelium growth and wheat blast disease symptoms in plants. Physicochemical characterization of the CuONPs performed by TEM and EDS showed elongated fibers in shape and an average size of 397 ± 55 nm in length and 124 ± 13 nm in width, as good physico-chemical stability. In vitro and in vivo experiments to evaluate the potential of CuONPs against PoT showed that they were effective in strongly inhibiting the mycelial growth of PoT native aggressive strains PY15, PY22 and PY34 by 74, 72 and 67% respectively, at a concentrationof 1000 ppm. Moreover, CuONPs at a concentration of 500 ppm applied as a foliar spray on wheat plants inoculated with PY34 caused a reduction of 95% in disease severity. Further, wheat plants in which their seeds were previously pelletized with 500 ppm CuONPs showed a disease symptom reduction of 90%. These findings confirm that the biosynthesized CuONPs have a promising antifungal activity, which could be used as protection of wheat against PoT pathogen. Santamarina, M. Pilar Giménez-Santamarina, Silvia Santamarina, Cristina Larrán, Silvina Roselló, Josefa http://sedici.unlp.edu.ar:80/handle/10915/181743 2025-07-14T20:10:52Z 2025-01-01T00:00:00Z

Articulo Molecules; vol. 30, no. 3 Cyperus esculentus L. var sativus is cultivated in Spain, only in the L’Horta Nord in the Valencia region. In this country, tubers are consumed fresh to make a popular beverage in the Valencia region called “horchata de chufa” (chufa milk). This drink is considered beneficial for human health thanks to its high nutritional value and medicinal importance in several treatments. This work evaluates the antifungal potential of the Thymus zygis essential oil against fungi found in tiger nut warehouses to preserve tubers under the best conditions. The analyzed commercial thyme essential oil belongs to the thymol/pcymene/ γ-terpinene chemotype. Thymol was found in larger quantities (51.34%), followed by the identified biogenetic precursors p-cymene (35.16%) and γ-terpinene (3.53%). Carvacrol also appeared, but in small quantities (3.53%). During in vitro tests, the T. zygis EO showed strong inhibition (98.85% to 91.81% MGI) against fungi Alternaria alternata, Fusarium andiyazi, Fusarium incarnatum, and Fusarium oxysporum at 300 μg/mL. It totally inhibited their growth (100% MGI) at 400 μg/mL, and did so strongly (75.94%, 72.02%, and 70.78%) with fungi Podospora australis, Penicillium commune, and Cladosporium subuliforme, respectively. Under in vivo conditions, formulated as a protective biofilm, and by forcing the environmental conditions of temperature and humidity to the maximum for fungus F. andiyazi growth on tiger nut tubers, the created film acted as a strong protector against fungal attacks.

2025-01-01T00:00:00Z Cyperus esculentus L. var sativus is cultivated in Spain, only in the L’Horta Nord in the Valencia region. In this country, tubers are consumed fresh to make a popular beverage in the Valencia region called “horchata de chufa” (chufa milk). This drink is considered beneficial for human health thanks to its high nutritional value and medicinal importance in several treatments. This work evaluates the antifungal potential of the Thymus zygis essential oil against fungi found in tiger nut warehouses to preserve tubers under the best conditions. The analyzed commercial thyme essential oil belongs to the thymol/pcymene/ γ-terpinene chemotype. Thymol was found in larger quantities (51.34%), followed by the identified biogenetic precursors p-cymene (35.16%) and γ-terpinene (3.53%). Carvacrol also appeared, but in small quantities (3.53%). During in vitro tests, the T. zygis EO showed strong inhibition (98.85% to 91.81% MGI) against fungi Alternaria alternata, Fusarium andiyazi, Fusarium incarnatum, and Fusarium oxysporum at 300 μg/mL. It totally inhibited their growth (100% MGI) at 400 μg/mL, and did so strongly (75.94%, 72.02%, and 70.78%) with fungi Podospora australis, Penicillium commune, and Cladosporium subuliforme, respectively. Under in vivo conditions, formulated as a protective biofilm, and by forcing the environmental conditions of temperature and humidity to the maximum for fungus F. andiyazi growth on tiger nut tubers, the created film acted as a strong protector against fungal attacks. Perelló, Analía Edith Romero-Munar, Antonia Martínez, Sergio Iván Busquets, Antonio Cañellas, María Quetglas, Bárbara M. Bosch, Rafael Vadell, Jaume Cabot, Catalina Gomila, Marga http://sedici.unlp.edu.ar:80/handle/10915/181451 2025-07-09T04:12:43Z 2025-06-01T00:00:00Z

Articulo Plants; vol. 14, no. 13 Grapevine (Vitis vinifera) is a key crop in Mediterranean agriculture, now increasingly threatened by Xylella fastidiosa subsp. Fastidiosa (Xff ), the causal agent of Pierce’s disease. This study investigated: (1) the diversity of culturable fungal endophytes in the xylem sap of naturally Xff -infected grapevines, and (2) the interaction between Xff and the pathogenic fungus Sclerotinia sclerotiorum identified in the sap. The xylem sap was collected from Cabernet Sauvignon vines in Mallorca, Spain, and fungal communities were characterized using culture-dependent methods. Both beneficial fungi (e.g., Aureobasidium pullulans, Rhodotorula mucilaginosa) and pathogenic species (e.g., S. sclerotiorum, Cladosporium sp., Alternaria alternata, and the Phoma complex) were isolated from both Xff -positive and Xff -negative plants, indicating similar community profiles. Although limited by small sample size, these findings offer preliminary evidence of complex ecological interactions between Xff and the xylem-associated mycobiota, with potential implications for grapevine health and disease development under varying environmental and management conditions. Further experiments under controlled conditions revealed that grapevines co-inoculated with Xff and S. sclerotiorum showed increased disease severity, suggesting a synergistic interaction. These preliminary results highlight the complex interplay between Xff and the fungal endophytic microbiome, which may modulate grapevine susceptibility depending on environmental and management conditions.

2025-06-01T00:00:00Z Grapevine (Vitis vinifera) is a key crop in Mediterranean agriculture, now increasingly threatened by Xylella fastidiosa subsp. Fastidiosa (Xff ), the causal agent of Pierce’s disease. This study investigated: (1) the diversity of culturable fungal endophytes in the xylem sap of naturally Xff -infected grapevines, and (2) the interaction between Xff and the pathogenic fungus Sclerotinia sclerotiorum identified in the sap. The xylem sap was collected from Cabernet Sauvignon vines in Mallorca, Spain, and fungal communities were characterized using culture-dependent methods. Both beneficial fungi (e.g., Aureobasidium pullulans, Rhodotorula mucilaginosa) and pathogenic species (e.g., S. sclerotiorum, Cladosporium sp., Alternaria alternata, and the Phoma complex) were isolated from both Xff -positive and Xff -negative plants, indicating similar community profiles. Although limited by small sample size, these findings offer preliminary evidence of complex ecological interactions between Xff and the xylem-associated mycobiota, with potential implications for grapevine health and disease development under varying environmental and management conditions. Further experiments under controlled conditions revealed that grapevines co-inoculated with Xff and S. sclerotiorum showed increased disease severity, suggesting a synergistic interaction. These preliminary results highlight the complex interplay between Xff and the fungal endophytic microbiome, which may modulate grapevine susceptibility depending on environmental and management conditions. Iturralde, Micaela Bracho Oliveros, Juan Pablo Valdivia-Pérez, Jessica A. Guzmán, Fanny Malbrán, Ismael Maté, Sabina María Fanani, María Laura Vairo Cavalli, Sandra Elizabeth http://sedici.unlp.edu.ar:80/handle/10915/181377 2025-07-07T20:11:45Z 2025-04-01T00:00:00Z

Articulo Antibiotics; vol. 14, no. 4 Background: The use of antimicrobial peptides (AMPs) as biotechnological tools is an area of growing interest in the research that seeks to improve crop defense. SmAPα1–21 and SmAPγ27–44 were previously reported to inhibit Fusarium graminearum, permeabilize the plasma membrane and induce cytoplasmic disorganization. To exert its activity, SmAPα1–21 initially enters through the basal and apical cells of F. graminearum conidia and then displays a general but non-homogeneous distribution in the cytoplasm of all conidial cells, in contrast. Methods: We analyzed, focusing on membrane interaction, the mode of action of SmAPγ27–44, a peptide based on the γ-core of defensins DefSm2-D and DefSm3, and SmAPα1–21, based on the α-core of DefSm2-D. Additionally, we compared the behavior of SmAPα1–21 with that of SmAP3α1–21 based on DefSm3 but with no activity against F. graminearum. Results: In this study, we showed that SmAPγ27–44 enters the cells with discrete intracellular localization. Furthermore, both peptides disrupted the plasma membrane, but with different modes of action. When large unilamellar liposomes (LUVs) containing phosphatidic acid and ergosterol were used as a filamentous fungal plasma membrane model, SmAPγ27–44 strongly induced aggregation concomitantly with the solubilization of the liposomes and showed the maximal insertion of its tryptophan moiety into the membrane’s hydrophobic interior. In comparison, SmAPα1–21 showed a high effect on the ζ potential of anionic vesicles, vesicle aggregation capacity after reaching a concentration threshold, and moderate transfer of tryptophan to the membrane. SmAP3α1–21, on the other hand, showed poor superficial adsorption to liposomes. Conclusions: In view of our results, a cell penetration peptide-like effect was pictured for the γ-core defensin-derived peptide and a classical AMP action was observed for the α-core defensin-derived one.

2025-04-01T00:00:00Z Background: The use of antimicrobial peptides (AMPs) as biotechnological tools is an area of growing interest in the research that seeks to improve crop defense. SmAPα1–21 and SmAPγ27–44 were previously reported to inhibit Fusarium graminearum, permeabilize the plasma membrane and induce cytoplasmic disorganization. To exert its activity, SmAPα1–21 initially enters through the basal and apical cells of F. graminearum conidia and then displays a general but non-homogeneous distribution in the cytoplasm of all conidial cells, in contrast. Methods: We analyzed, focusing on membrane interaction, the mode of action of SmAPγ27–44, a peptide based on the γ-core of defensins DefSm2-D and DefSm3, and SmAPα1–21, based on the α-core of DefSm2-D. Additionally, we compared the behavior of SmAPα1–21 with that of SmAP3α1–21 based on DefSm3 but with no activity against F. graminearum. Results: In this study, we showed that SmAPγ27–44 enters the cells with discrete intracellular localization. Furthermore, both peptides disrupted the plasma membrane, but with different modes of action. When large unilamellar liposomes (LUVs) containing phosphatidic acid and ergosterol were used as a filamentous fungal plasma membrane model, SmAPγ27–44 strongly induced aggregation concomitantly with the solubilization of the liposomes and showed the maximal insertion of its tryptophan moiety into the membrane’s hydrophobic interior. In comparison, SmAPα1–21 showed a high effect on the ζ potential of anionic vesicles, vesicle aggregation capacity after reaching a concentration threshold, and moderate transfer of tryptophan to the membrane. SmAP3α1–21, on the other hand, showed poor superficial adsorption to liposomes. Conclusions: In view of our results, a cell penetration peptide-like effect was pictured for the γ-core defensin-derived peptide and a classical AMP action was observed for the α-core defensin-derived one. Medina, Rocío Franco, Mario Emilio Ernesto Lucentini, César Gustavo Rosso, Janina Alejandra Saparrat, Mario Carlos Nazareno Bartel, Laura Cecilia Balatti, Pedro Alberto http://sedici.unlp.edu.ar:80/handle/10915/160262 2023-11-22T20:03:45Z 2019-01-01T00:00:00Z

Articulo Current Plant Biology; vol. 20 The aim of this work was to study the volatile organic compounds (VOCs) profile and diffusible secondary metabolites (SMs) of Stemphylium lycopersici and Fulvia fulva, two fungal pathogens of tomato. S. lycopersici synthesizes and releases quantitatively more VOCs than F. fulva, probably due to the different type of interaction that each fungus establishes with tomato; nevertheless, F. fulva synthesized a specific and more diverse spectrum of VOCs. S. lycopersici released VOCs that triggering cell death in tomato leaves. Also, F. fulva synthesized an ample array of SMs but their biological roles remain to be elucidated.

2019-01-01T00:00:00Z The aim of this work was to study the volatile organic compounds (VOCs) profile and diffusible secondary metabolites (SMs) of Stemphylium lycopersici and Fulvia fulva, two fungal pathogens of tomato. S. lycopersici synthesizes and releases quantitatively more VOCs than F. fulva, probably due to the different type of interaction that each fungus establishes with tomato; nevertheless, F. fulva synthesized a specific and more diverse spectrum of VOCs. S. lycopersici released VOCs that triggering cell death in tomato leaves. Also, F. fulva synthesized an ample array of SMs but their biological roles remain to be elucidated. Alippi, Adriana Mónica Lamelza, Florencia Torres Tejerizo, Gonzalo Arturo Abrahamovich, Eliana López, Ana Claudia http://sedici.unlp.edu.ar:80/handle/10915/159941 2023-11-08T20:03:49Z 2023-01-01T00:00:00Z

Articulo Identificación, análisis filogenético y minería genómica de la cepa de Bacillus thuringiensis m401 resistente a tetraciclina, y sus posibles aplicaciones biotecnológicas y de biocontrol Revista Argentina de Microbiología; 2023 Bacillus thuringiensis is an entomopathogen belonging to the Bacillus cereus clade. We isolated a tetracycline-resistant strain called m401, recovered it from honey, and identified it as Bacillus thuringiensis sv. kumamotoensis based on the average nucleotide identity calculations (ANIb) comparison and the analysis of the gyrB gene sequences of different B. thuringiensis serovars. Sequences with homology to virulence factors [cytK, nheA, nheB, nheC, hblA, hblB, hblC, hblD, entFM, and inhA] and tetracycline resistance genes [tet(45), tet(V), and tet(M)/tet(W)/tet(O)/tet(S) family] were identified in the bacterial chromosome. The prediction of plasmid-coding regions revealed homolog sequences to the MarR and TetR/AcrR family of transcriptional regulators, toxins, and lantipeptides. The genome mining analysis revealed 12 regions of biosynthetic gene clusters responsible for synthesizing secondary metabolites. We identified biosynthetic gene clusters coding for bacteriocins, siderophores, ribosomally synthesized post-translationally modified peptide products, and non-ribosomal peptide synthetase clusters that provide evidence for the possible use of Bt m401 as a biocontrol agent. Furthermore, Bt m401 showed high inhibition against all Paenibacillus larvae genotypes tested in vitro. In conclusion, Bt m401 owns various genes involved in different biological processes, such as transductional regulators associated with antibiotic resistance, toxins, and antimicrobial peptides with potential biotechnological and biocontrol applications.; Bacillus thuringiensis es un microorganismo entomopatógeno perteneciente al clado Bacillus cereus. En este trabajo, aislamos de miel una cepa resistente a tetraciclina y la identificamos como Bacillus thuringiensis sv. kumamotoensis (Bt m401) mediante comparación de genomas completos y cálculo de identidad promedio de nucleótidos (ANIb), utilizando la base de datos EDGAR. Este resultado fue corroborado por el análisis filogenético del gen gyrB, que permite diferenciar serovares de B. thuringiensis. Se confirmó la presencia del gen de resistencia a tetraciclina tet(45) en el cromosoma bacteriano y se identificaron secuencias homólogas a genes de virulencia (cytK, nheA, nheB, nheC, hblA, hblB, hblC, hblD y entFM). El mobiloma de Bt m401 está constituido por 4 plásmidos y se identificaron secuencias homólogas a reguladores transduccionales (MarR y TetR/AcR), a toxinas (Cry1 y zeta toxin) y a péptidos antimicrobianos (mersacidin family lantibiotics). La cepa Bt m401 demostró una muy buena actividad antagónica in vitro contra distintos genotipos de Paenibacillus larvae, agente causal de la loque americana de las abejas. El estudio de minería genómica para grupos de genes biosintéticos reveló 12 regiones de clústeres de genes responsables de la síntesis de metabolitos secundarios. Se identificaron clústeres que codifican bacteriocinas, sideróforos, RiPP-like y NRPS y lantipéptidos. En conclusión, Bt m401 presentó una amplia variedad de genes que estarían involucrados en diferentes procesos biológicos, con un potencial interesante para su empleo en aplicaciones biotecnológicas.

2023-01-01T00:00:00Z Bacillus thuringiensis is an entomopathogen belonging to the Bacillus cereus clade. We isolated a tetracycline-resistant strain called m401, recovered it from honey, and identified it as Bacillus thuringiensis sv. kumamotoensis based on the average nucleotide identity calculations (ANIb) comparison and the analysis of the gyrB gene sequences of different B. thuringiensis serovars. Sequences with homology to virulence factors [cytK, nheA, nheB, nheC, hblA, hblB, hblC, hblD, entFM, and inhA] and tetracycline resistance genes [tet(45), tet(V), and tet(M)/tet(W)/tet(O)/tet(S) family] were identified in the bacterial chromosome. The prediction of plasmid-coding regions revealed homolog sequences to the MarR and TetR/AcrR family of transcriptional regulators, toxins, and lantipeptides. The genome mining analysis revealed 12 regions of biosynthetic gene clusters responsible for synthesizing secondary metabolites. We identified biosynthetic gene clusters coding for bacteriocins, siderophores, ribosomally synthesized post-translationally modified peptide products, and non-ribosomal peptide synthetase clusters that provide evidence for the possible use of Bt m401 as a biocontrol agent. Furthermore, Bt m401 showed high inhibition against all Paenibacillus larvae genotypes tested in vitro. In conclusion, Bt m401 owns various genes involved in different biological processes, such as transductional regulators associated with antibiotic resistance, toxins, and antimicrobial peptides with potential biotechnological and biocontrol applications. Bacillus thuringiensis es un microorganismo entomopatógeno perteneciente al clado Bacillus cereus. En este trabajo, aislamos de miel una cepa resistente a tetraciclina y la identificamos como Bacillus thuringiensis sv. kumamotoensis (Bt m401) mediante comparación de genomas completos y cálculo de identidad promedio de nucleótidos (ANIb), utilizando la base de datos EDGAR. Este resultado fue corroborado por el análisis filogenético del gen gyrB, que permite diferenciar serovares de B. thuringiensis. Se confirmó la presencia del gen de resistencia a tetraciclina tet(45) en el cromosoma bacteriano y se identificaron secuencias homólogas a genes de virulencia (cytK, nheA, nheB, nheC, hblA, hblB, hblC, hblD y entFM). El mobiloma de Bt m401 está constituido por 4 plásmidos y se identificaron secuencias homólogas a reguladores transduccionales (MarR y TetR/AcR), a toxinas (Cry1 y zeta toxin) y a péptidos antimicrobianos (mersacidin family lantibiotics). La cepa Bt m401 demostró una muy buena actividad antagónica in vitro contra distintos genotipos de Paenibacillus larvae, agente causal de la loque americana de las abejas. El estudio de minería genómica para grupos de genes biosintéticos reveló 12 regiones de clústeres de genes responsables de la síntesis de metabolitos secundarios. Se identificaron clústeres que codifican bacteriocinas, sideróforos, RiPP-like y NRPS y lantipéptidos. En conclusión, Bt m401 presentó una amplia variedad de genes que estarían involucrados en diferentes procesos biológicos, con un potencial interesante para su empleo en aplicaciones biotecnológicas. Larrán, Silvina Simón, María Rosa Santamarina, María Pilar Roselló Caselles, Josefa Consolo, Verónica Fabiana Perelló, Analía Edith http://sedici.unlp.edu.ar:80/handle/10915/159776 2023-11-03T20:03:47Z 2023-01-01T00:00:00Z

Articulo Journal of the Saudi Society of Agricultural Sciences; vol. 22, no. 7 Charcoal rot, caused by Macrophomina phaseolina (Tassi) Goid., is one of the world’s most serious diseases because it reduces yield and seed quality. Nowadays, biological control is an environment-friendly option for controlling plant diseases. The goals of this study were to (i) test eight endophytic Trichoderma spp. strains as biocontrol agents against M. phaseolina and (ii) further investigate two selected strains showing good behaviour against the pathogen. Pathogen-antagonist interactions were studied in dual culture, and the morphological alterations of M. phaseolina mycelia in the interaction zone were examined by light microscopy. Trichoderma strains were applied to soya bean seeds by a seed coating technique. Their bioprotective effects were assessed by in vitro and in vivo assays to evaluate radicle length, the germination percentage and the presence of typical charcoal rot symptoms in seedlings. Two Trichoderma strains were selected and they were molecularly identified as T. harzianum species complex. Their antagonistic ability against M. phaseolina was evaluated under different water availability conditions. The mechanisms used by these two endophytic strains against the pathogen were evaluated by cryo-scanning electron microscopy. The results showed that all eight Trichoderma strains successfully performed biocontrol activity against M. phaseolina by reducing colony growth and causing morphological alterations in the mycelia of M. phaseolina. All endophytes improved seed germination and radicle length, and reduced typical symptoms and disease progression on seedlings. Water availability in the medium impacted on fungal growth. At 0.995 ɑw, all the fungi grew more and faster. At 0.95 ɑw M. phaseolina grew more than the Trichoderma strains, while the pathogen grew slightly more at 0.98 ɑw than the Trichoderma strains. However, both selected Trichoderma strains grew larger and faster than the pathogen at 0.995 ɑw. The mechanisms involved in pathogen control revealed by the light and cryo-scanning microscopy studies included competition for nutrients or space and direct mycoparasitism. All the endophytic Trichoderma strains were antagonistic against M. phaseolina, however our study allowed us to select two Trichoderma strains with good potential to be included for charcoal rot management.

2023-01-01T00:00:00Z Charcoal rot, caused by Macrophomina phaseolina (Tassi) Goid., is one of the world’s most serious diseases because it reduces yield and seed quality. Nowadays, biological control is an environment-friendly option for controlling plant diseases. The goals of this study were to (i) test eight endophytic Trichoderma spp. strains as biocontrol agents against M. phaseolina and (ii) further investigate two selected strains showing good behaviour against the pathogen. Pathogen-antagonist interactions were studied in dual culture, and the morphological alterations of M. phaseolina mycelia in the interaction zone were examined by light microscopy. Trichoderma strains were applied to soya bean seeds by a seed coating technique. Their bioprotective effects were assessed by in vitro and in vivo assays to evaluate radicle length, the germination percentage and the presence of typical charcoal rot symptoms in seedlings. Two Trichoderma strains were selected and they were molecularly identified as T. harzianum species complex. Their antagonistic ability against M. phaseolina was evaluated under different water availability conditions. The mechanisms used by these two endophytic strains against the pathogen were evaluated by cryo-scanning electron microscopy. The results showed that all eight Trichoderma strains successfully performed biocontrol activity against M. phaseolina by reducing colony growth and causing morphological alterations in the mycelia of M. phaseolina. All endophytes improved seed germination and radicle length, and reduced typical symptoms and disease progression on seedlings. Water availability in the medium impacted on fungal growth. At 0.995 ɑw, all the fungi grew more and faster. At 0.95 ɑw M. phaseolina grew more than the Trichoderma strains, while the pathogen grew slightly more at 0.98 ɑw than the Trichoderma strains. However, both selected Trichoderma strains grew larger and faster than the pathogen at 0.995 ɑw. The mechanisms involved in pathogen control revealed by the light and cryo-scanning microscopy studies included competition for nutrients or space and direct mycoparasitism. All the endophytic Trichoderma strains were antagonistic against M. phaseolina, however our study allowed us to select two Trichoderma strains with good potential to be included for charcoal rot management. D'Amico, Gabriela Mariana Fucks, Enrique Eduardo Carut, Claudia Beatriz http://sedici.unlp.edu.ar:80/handle/10915/158201 2023-09-29T20:04:56Z 2022-01-01T00:00:00Z

Objeto de conferencia VIII Congreso Argentino de Cuaternario y Geomorfología (San Juan, 19 al 23 de septiembre de 2022); Libro de Actas - VIII Congreso Argentino de Cuaternario y Geomorfología - San Juan 2022 El presente trabajo analiza los cambios en la línea de costa y en el uso del suelo en tres sitios de la costa del estuario del Río de la Plata, donde dinámicas naturales y antrópicas actúan en conjunto: 1) Isla Paulino (1936-2016); 2) Atalaya (1929 - 2016) y 3) desembocadura de los ríos Salado y Samborombón, (1931-2018)

2022-01-01T00:00:00Z El presente trabajo analiza los cambios en la línea de costa y en el uso del suelo en tres sitios de la costa del estuario del Río de la Plata, donde dinámicas naturales y antrópicas actúan en conjunto: 1) Isla Paulino (1936-2016); 2) Atalaya (1929 - 2016) y 3) desembocadura de los ríos Salado y Samborombón, (1931-2018) Murace, Mónica Adriana Luna, María Luján Lucentini, César Gustavo Maly, Laura Elizabeth Perelló, Analía Edith Saparrat, Mario Carlos Nazareno http://sedici.unlp.edu.ar:80/handle/10915/153856 2023-06-02T20:03:55Z 2022-10-01T00:00:00Z

Articulo White rot in heartwood of Melia azedarach (Meliaceae) specimens from urban trees of La Plata (Buenos Aires): causal agent and chemical-anatomical characterization of the attacked wood Lilloa; vol. 59, supl. Los hongos xilófagos atacan frecuentemente ejemplares del arbolado urbano descomponiendo su madera. Esto afecta negativamente la estabilidad y resistencia al quiebre, poniendo en riesgo a la población y sus bienes. Durante un relevamiento de las pudriciones presentes en el arbolado de la ciudad de La Plata, fueron observados ejemplares de Melia azedarach (Meliaceae) con evidencias de pudrición blanca en duramen expuesto. El objetivo del trabajo fue identificar al hongo responsable de esta pudrición y analizar las alteraciones anatómicas y químicas que causa en el leño. Se examinaron muestras de duramen con evidencias de pudrición blanca en estadios intermedio y avanzado extraídas de fuste y rama, respectivamente. Los aislamientos fúngicos fueron obtenidos de secciones de madera sembradas en agar malta con antibiótico y fungicida. La identificación fue llevada a cabo a partir de las características de las colonias y confirmada mediante técnicas moleculares. Los estudios anatómicos fueron realizados con microscopios estereoscópico, óptico y electrónico de barrido, y los análisis químicos mediante química húmeda y espectroscopía infrarroja transformada de Fourier (FT-IR). Phlebia brevispora (Basidiomycota, Polyporales) fue la única especie xilófaga aislada del material. Las alteraciones anatómicas registradas permitieron diagnosticar pudrición blanca simultánea en fuste y coexistencia de pudrición blanca simultánea y selectiva en rama. Mediante química húmeda fueron determinados incrementos relativos en el tenor de lignina y extraíbles lipofílicos, y disminuciones en el porcentaje de los extraíbles hidrofílicos en las muestras de ambos estadios de degradación (rama y fuste); la disminución del tenor de celulosa sólo fue identificada en rama. El FT-IR reveló el ataque a la celulosa y la lignina. Si bien existe información previa de la presencia P. brevispora en árboles en pie, el presente hallazgo constituye el primer registro para la Argentina, mientras que la interacción P. brevispora - Melia azedarach es reportada por primera vez en esta contribución.; The xylophagous fungi frequently attack specimens of urban trees, decomposing their wood. This negatively affects stability and resistance to breakdown, putting the population and their goods at risk. During a survey of the rot present in the trees of La Plata city, specimens of Melia azedarach (Meliaceae) with evidence of white rot in exposed heartwood were observed. The aim of this work was to identify the fungus responsible for this rot and to analyze the anatomical and chemical alterations it causes in the wood. Heartwood samples with evidence of white rot in intermediate and advanced stages attained from stem and branch, respectively, were used. Fungal isolates were obtained from wood sections cultured on malt agar with antibiotic and fungicide. The identification was based on the characteristics of the colonies and confirmed by molecular techniques. Anatomical studies were performed with stereoscopic, optical and scanning electron microscopes and the chemical analysis by using wet chemistry and Fourier transform infrared spectroscopy (FT-IR). Phlebia brevispora (Basidiomycota, Polyporales) was the only xylophagous species isolated from the material. The anatomical alterations recorded allowed the diagnosis of simultaneous white rot in the stem and the coexistence of simultaneous and selective white rot in branch. Through wet chemistry, relative increases in the content of lignin and lipophilic extracts were determined, and decreases in the percentage of hydrophilic extractables in the samples of both degradation stages (branch and stem); the decrease in cellulose content was only identified in branch. FT-IR revealed the attack on cellulose and lignin. Although there is previous information about the presence of P. brevispora in standing trees, the current finding constitutes the first record for Argentina, while the interaction P. brevispora – Melia azedarach is reported for the first time in this contribution.

2022-10-01T00:00:00Z Los hongos xilófagos atacan frecuentemente ejemplares del arbolado urbano descomponiendo su madera. Esto afecta negativamente la estabilidad y resistencia al quiebre, poniendo en riesgo a la población y sus bienes. Durante un relevamiento de las pudriciones presentes en el arbolado de la ciudad de La Plata, fueron observados ejemplares de Melia azedarach (Meliaceae) con evidencias de pudrición blanca en duramen expuesto. El objetivo del trabajo fue identificar al hongo responsable de esta pudrición y analizar las alteraciones anatómicas y químicas que causa en el leño. Se examinaron muestras de duramen con evidencias de pudrición blanca en estadios intermedio y avanzado extraídas de fuste y rama, respectivamente. Los aislamientos fúngicos fueron obtenidos de secciones de madera sembradas en agar malta con antibiótico y fungicida. La identificación fue llevada a cabo a partir de las características de las colonias y confirmada mediante técnicas moleculares. Los estudios anatómicos fueron realizados con microscopios estereoscópico, óptico y electrónico de barrido, y los análisis químicos mediante química húmeda y espectroscopía infrarroja transformada de Fourier (FT-IR). Phlebia brevispora (Basidiomycota, Polyporales) fue la única especie xilófaga aislada del material. Las alteraciones anatómicas registradas permitieron diagnosticar pudrición blanca simultánea en fuste y coexistencia de pudrición blanca simultánea y selectiva en rama. Mediante química húmeda fueron determinados incrementos relativos en el tenor de lignina y extraíbles lipofílicos, y disminuciones en el porcentaje de los extraíbles hidrofílicos en las muestras de ambos estadios de degradación (rama y fuste); la disminución del tenor de celulosa sólo fue identificada en rama. El FT-IR reveló el ataque a la celulosa y la lignina. Si bien existe información previa de la presencia P. brevispora en árboles en pie, el presente hallazgo constituye el primer registro para la Argentina, mientras que la interacción P. brevispora - Melia azedarach es reportada por primera vez en esta contribución. The xylophagous fungi frequently attack specimens of urban trees, decomposing their wood. This negatively affects stability and resistance to breakdown, putting the population and their goods at risk. During a survey of the rot present in the trees of La Plata city, specimens of Melia azedarach (Meliaceae) with evidence of white rot in exposed heartwood were observed. The aim of this work was to identify the fungus responsible for this rot and to analyze the anatomical and chemical alterations it causes in the wood. Heartwood samples with evidence of white rot in intermediate and advanced stages attained from stem and branch, respectively, were used. Fungal isolates were obtained from wood sections cultured on malt agar with antibiotic and fungicide. The identification was based on the characteristics of the colonies and confirmed by molecular techniques. Anatomical studies were performed with stereoscopic, optical and scanning electron microscopes and the chemical analysis by using wet chemistry and Fourier transform infrared spectroscopy (FT-IR). Phlebia brevispora (Basidiomycota, Polyporales) was the only xylophagous species isolated from the material. The anatomical alterations recorded allowed the diagnosis of simultaneous white rot in the stem and the coexistence of simultaneous and selective white rot in branch. Through wet chemistry, relative increases in the content of lignin and lipophilic extracts were determined, and decreases in the percentage of hydrophilic extractables in the samples of both degradation stages (branch and stem); the decrease in cellulose content was only identified in branch. FT-IR revealed the attack on cellulose and lignin. Although there is previous information about the presence of P. brevispora in standing trees, the current finding constitutes the first record for Argentina, while the interaction P. brevispora – Melia azedarach is reported for the first time in this contribution. Vio, Santiago Adolfo Galar, María Lina Gortari, María Cecilia Balatti, Pedro Alberto Garbi, Mariana Lodeiro, Aníbal Roberto Luna, María Flavia http://sedici.unlp.edu.ar:80/handle/10915/152924 2023-05-13T04:03:45Z 2023-01-01T00:00:00Z

Articulo Plants; vol. 12, no. 4 The use of multispecies bacterial bio-inputs is a promising strategy for sustainable crop production over the use of single-species inoculants. Studies of the use of multispecies bio-inputs in horticultural crops are scarce, not only on the growth-promoting effects of each bacterium within the formulation, but also on their compatibility and persistence in the root environment. In this work, we described that a multispecies bacterial bio-input made up of Azospirillum argentinense Az39, Gluconacetobacter diazotrophicus PAL-5, Pseudomonas protegens Pf-5 and Bacillus sp. Dm-B10 improved lettuce plant growth more effectively than when these strains were inoculated as single-species bio-inputs. Bacteria persisted together (were compatible) and also colonized seedling roots of lettuce plants grown in controlled conditions. Interestingly, colonization was highly related to an early and enhanced growth of seedlings grown in the nursery. A similar effect on plant growth was found in lettuce plants in a commercial greenhouse production in the peri-urban area of La Plata City, Buenos Aires, Argentina. To our knowledge, this is the first study demonstrating that a synthetic mixture of bacteria can colonize and persist on lettuce plants, and also showing their synergistic beneficial effect both in the nursery greenhouse as well as the commercial production farm.

2023-01-01T00:00:00Z The use of multispecies bacterial bio-inputs is a promising strategy for sustainable crop production over the use of single-species inoculants. Studies of the use of multispecies bio-inputs in horticultural crops are scarce, not only on the growth-promoting effects of each bacterium within the formulation, but also on their compatibility and persistence in the root environment. In this work, we described that a multispecies bacterial bio-input made up of Azospirillum argentinense Az39, Gluconacetobacter diazotrophicus PAL-5, Pseudomonas protegens Pf-5 and Bacillus sp. Dm-B10 improved lettuce plant growth more effectively than when these strains were inoculated as single-species bio-inputs. Bacteria persisted together (were compatible) and also colonized seedling roots of lettuce plants grown in controlled conditions. Interestingly, colonization was highly related to an early and enhanced growth of seedlings grown in the nursery. A similar effect on plant growth was found in lettuce plants in a commercial greenhouse production in the peri-urban area of La Plata City, Buenos Aires, Argentina. To our knowledge, this is the first study demonstrating that a synthetic mixture of bacteria can colonize and persist on lettuce plants, and also showing their synergistic beneficial effect both in the nursery greenhouse as well as the commercial production farm. Toledo, Andrea Vanesa Brentassi, María Eugenia http://sedici.unlp.edu.ar:80/handle/10915/151449 2023-04-13T20:06:03Z 2022-02-01T00:00:00Z

Articulo Entomologia Experimentalis et Applicata; vol. 170, no. 2; http://sedici.unlp.edu.ar/handle/10915/117084 Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) is the main planthopper vector of Mal de R ıo Cuarto virus (MRCV), a Fijivirus that severely affects maize production in Argentina. The effect of several nutritional sources on the virulence of Beauveria bassiana s.l. CEP147 (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) against this planthopper was evaluated with the aim to select some of them to be incorporated in future mass production studies. Ten agar-agar 2% media were used. Media were supplemented with 10 g of sucrose and 4% flour of either amaranth, chia, flax, oat bran, parboiled rice, poppy, quinoa, or wheat germ. Sabouraud dextrose agar with 1% yeast extract (SDAY) was used as control, and sucrose agar medium supplemented with 2% chitin was used as a possible inductor of enzymatic activity. We evaluated the effect of each medium on colony growth, conidial yield, viability, size, adherence, hydrophobicity, protease activity, cumulative mortality, and median survival time (MST). Principal component analysis indicated that conidial viability and adherence explained the most of the total variance, indicating that these variables can be used as indicators of fungal virulence. Medium supplemented with chia flour not only increased conidial viability (100%) and adherence (0.09 A550) with respect to the control medium, but also produced high D. kuscheli mortality (91.7%), with the lowest MST (5.2 days).We suggest that chia flour, which is rich in carbohydrates, proteins, vitamins, andminerals, might be incorporated as a nutritional supplement to solid substrates in order to increase the virulence of B. bassiana s.l. CEP147 against this and other pests. However, future studies are necessary to evaluate the effectiveness of this nutritional source on solid-state fermentation. Puede accederse a los datos utilizados para este artículo haciendo clic en "Documentos relacionados".

2022-02-01T00:00:00Z Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) is the main planthopper vector of Mal de R ıo Cuarto virus (MRCV), a Fijivirus that severely affects maize production in Argentina. The effect of several nutritional sources on the virulence of Beauveria bassiana s.l. CEP147 (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) against this planthopper was evaluated with the aim to select some of them to be incorporated in future mass production studies. Ten agar-agar 2% media were used. Media were supplemented with 10 g of sucrose and 4% flour of either amaranth, chia, flax, oat bran, parboiled rice, poppy, quinoa, or wheat germ. Sabouraud dextrose agar with 1% yeast extract (SDAY) was used as control, and sucrose agar medium supplemented with 2% chitin was used as a possible inductor of enzymatic activity. We evaluated the effect of each medium on colony growth, conidial yield, viability, size, adherence, hydrophobicity, protease activity, cumulative mortality, and median survival time (MST). Principal component analysis indicated that conidial viability and adherence explained the most of the total variance, indicating that these variables can be used as indicators of fungal virulence. Medium supplemented with chia flour not only increased conidial viability (100%) and adherence (0.09 A550) with respect to the control medium, but also produced high D. kuscheli mortality (91.7%), with the lowest MST (5.2 days).We suggest that chia flour, which is rich in carbohydrates, proteins, vitamins, andminerals, might be incorporated as a nutritional supplement to solid substrates in order to increase the virulence of B. bassiana s.l. CEP147 against this and other pests. However, future studies are necessary to evaluate the effectiveness of this nutritional source on solid-state fermentation. Reynaldi, Francisco José Sguazza, Guillermo Hernán Pecoraro, Marcelo Ricardo Ítalo Tizzano, Marco Antonio Galosi, Cecilia Mónica http://sedici.unlp.edu.ar:80/handle/10915/149216 2023-02-23T20:07:53Z 2010-01-01T00:00:00Z

Articulo Environmental Microbiology Reports; vol. 2, no. 6 Honey is one of the most important agricultural products for export in Argentina. In fact, more than 3.5 million beehives and 50 000 beekeepers are related with this production, mainly located in Buenos Aires province. Honeybee mortality is a serious problem that beekeepers in Argentina have had to face during the last 3 years. It is known that the consequence of the complex interactions between environmental and beekeeping parameters added to the effect of different disease agents such as viruses, bacteria, fungi and parasitic mites may result in a sudden collapse of the colony. In addition, multiple viral infections are frequently detected concomitantly in bee colonies. We describe here the preliminary results of a survey of three honeybee-pathogenic viruses, acute bee paralysis viruses (ABPV), chronic bee paralysis viruses (CBPV) and Sacbrood viruses (SBV) detected during a screening of 61 apiaries located in the main honey producer province using a RT-PCR assay. This is the first molecular report of the presence of these viruses in Argentine apiaries.

2010-01-01T00:00:00Z Honey is one of the most important agricultural products for export in Argentina. In fact, more than 3.5 million beehives and 50 000 beekeepers are related with this production, mainly located in Buenos Aires province. Honeybee mortality is a serious problem that beekeepers in Argentina have had to face during the last 3 years. It is known that the consequence of the complex interactions between environmental and beekeeping parameters added to the effect of different disease agents such as viruses, bacteria, fungi and parasitic mites may result in a sudden collapse of the colony. In addition, multiple viral infections are frequently detected concomitantly in bee colonies. We describe here the preliminary results of a survey of three honeybee-pathogenic viruses, acute bee paralysis viruses (ABPV), chronic bee paralysis viruses (CBPV) and Sacbrood viruses (SBV) detected during a screening of 61 apiaries located in the main honey producer province using a RT-PCR assay. This is the first molecular report of the presence of these viruses in Argentine apiaries. Larrán, Silvina Ronco, Blanca Lía Carranza, Marcelo Ricardo Zúccaro, Martín Aníbal http://sedici.unlp.edu.ar:80/handle/10915/145246 2022-11-04T20:04:52Z 2004-01-01T00:00:00Z

Comunicacion Australasian Plant Pathology; vol. 33, no. 3 During the growing season 2000–2001, symptoms of rot and brown to black mummified buds were observed on artichoke plants cultivated in Arana, Buenos Aires, Argentina, an area of intensive horticulture production. The present study was undertaken in order to determine the aetiology of the disease. The fungus isolated was identified as Botrytis cinerea. Pathogenicity was confirmed by inoculating buds of globe artichoke plants and cut buds with a spore suspension. Inoculated plants and cut buds developed symptoms and spores characteristic of grey mould. B. cinerea was re-isolated from inoculated buds. This work confirms the presence the grey mould, caused by Botrytis cinerea, on artichoke in Argentina.

2004-01-01T00:00:00Z During the growing season 2000–2001, symptoms of rot and brown to black mummified buds were observed on artichoke plants cultivated in Arana, Buenos Aires, Argentina, an area of intensive horticulture production. The present study was undertaken in order to determine the aetiology of the disease. The fungus isolated was identified as Botrytis cinerea. Pathogenicity was confirmed by inoculating buds of globe artichoke plants and cut buds with a spore suspension. Inoculated plants and cut buds developed symptoms and spores characteristic of grey mould. B. cinerea was re-isolated from inoculated buds. This work confirms the presence the grey mould, caused by Botrytis cinerea, on artichoke in Argentina. Perelló, Analía Edith Sisterna, Marina Noemí http://sedici.unlp.edu.ar:80/handle/10915/145238 2022-11-04T20:04:54Z 2008-01-01T00:00:00Z

Articulo Australasian Plant Pathology; vol. 37, no. 6 The trapping of pseudothecia carrying asci with mature ascospores of Lewia infectoria (teleomorph of Alternaria infectoria) from wheat stubble under natural field conditions in Buenos Aires Province, Argentina, is reported for the first time. The production of mature pseudothecia in culture is also reported. Monosporic isolates of A. infectoria, obtained from infected wheat plants in Argentina, produced conidia within a week and ascomata with fully mature ascospores within 7 months when stored on slants of PCA at 4°Cin darkness. The anamorph exhibited the sporulation pattern of Alternaria infectoria species-group, and was identified by its axenic colony morphology and the prominence of its secondary conidiophore structure. Critical examination of the teleomorph revealed it to be Lewia infectoria. The presence of the teleomorph has implications in the long-distance dispersal of A. infectoria and on resistance breeding programs. This is the first confirmed report of the sexual stage of A. infectoria in Argentina.

2008-01-01T00:00:00Z The trapping of pseudothecia carrying asci with mature ascospores of Lewia infectoria (teleomorph of Alternaria infectoria) from wheat stubble under natural field conditions in Buenos Aires Province, Argentina, is reported for the first time. The production of mature pseudothecia in culture is also reported. Monosporic isolates of A. infectoria, obtained from infected wheat plants in Argentina, produced conidia within a week and ascomata with fully mature ascospores within 7 months when stored on slants of PCA at 4°Cin darkness. The anamorph exhibited the sporulation pattern of Alternaria infectoria species-group, and was identified by its axenic colony morphology and the prominence of its secondary conidiophore structure. Critical examination of the teleomorph revealed it to be Lewia infectoria. The presence of the teleomorph has implications in the long-distance dispersal of A. infectoria and on resistance breeding programs. This is the first confirmed report of the sexual stage of A. infectoria in Argentina. Consolo, Verónica Fabiana Cordo, Cristina Alicia Salerno, Graciela Lidia http://sedici.unlp.edu.ar:80/handle/10915/144408 2022-10-25T04:04:32Z 2008-07-01T00:00:00Z

Articulo Australasian Plant Pathology; vol. 37, no. 4 The genetic diversity of the rice blast pathogen, <i>Pyricularia oryzae</i>, was analysed in rice-growing provinces of Argentina. A total of 161 isolates of the fungus was collected from 15 rice cultivars at nine locations during 2000-05 and characterised using Pot2-DNA fingerprinting. Based on DNA analysis (isolates with ≥70% band similarity), five lineages were identified and designated A, B, C, D and E, with 11, 22, 4, 1 and 4 haplotypes identified, respectively. The predominant lineage, B, representing 38% of the collected isolates, was recovered from four cultivars in five locations. In contrast to lineages A and B, which did not contain a dominant haplotype, a single haplotype predominated in lineages C and E. Isolates representing all haplotypes were examined for virulence on a set of differential rice cultivars, near-isogenic lines and commercial cultivars commonly grown in Argentina, revealing 41 pathotypes and 24 international races. There was no significant association between DNA fingerprint similarities and pathotypes. Overall, these data indicated that populations of <i>P. oryzae</i> in Argentina are genetically simple and predominantly clonal yet have a high pathotype diversity.

2008-07-01T00:00:00Z The genetic diversity of the rice blast pathogen, <i>Pyricularia oryzae</i>, was analysed in rice-growing provinces of Argentina. A total of 161 isolates of the fungus was collected from 15 rice cultivars at nine locations during 2000-05 and characterised using Pot2-DNA fingerprinting. Based on DNA analysis (isolates with ≥70% band similarity), five lineages were identified and designated A, B, C, D and E, with 11, 22, 4, 1 and 4 haplotypes identified, respectively. The predominant lineage, B, representing 38% of the collected isolates, was recovered from four cultivars in five locations. In contrast to lineages A and B, which did not contain a dominant haplotype, a single haplotype predominated in lineages C and E. Isolates representing all haplotypes were examined for virulence on a set of differential rice cultivars, near-isogenic lines and commercial cultivars commonly grown in Argentina, revealing 41 pathotypes and 24 international races. There was no significant association between DNA fingerprint similarities and pathotypes. Overall, these data indicated that populations of <i>P. oryzae</i> in Argentina are genetically simple and predominantly clonal yet have a high pathotype diversity. Agnello, Ana Carolina Morelli, Irma Susana Del Panno, María Teresa http://sedici.unlp.edu.ar:80/handle/10915/143571 2022-10-11T20:04:34Z 2020-04-02T00:00:00Z

Capitulo de libro Plant Microbe Symbiosis The use of green remediation technologies (i.e., phytoremediation, bioremediation, mycoremediation) for the restoration of hydrocarbon-contaminated sites is one of the keys for sustainable development. These technologies rely on the joint action of biotic components of the ecosystem, namely, plants, bacteria, and fungi. Despite the fact that previous studies showed that the clean-up of hydrocarbons could be achieved individually by plants or microorganisms, present investigations suggest that the interaction of plants with their surrounding microbiome determines the outcomes of green remediation technologies. This book chapter reviews the state of the art to explain the two-way relationship established between plants and their associated microbiome in hydrocarbon-polluted soils. Special focus is put on stressing the results obtained in recent studies that employ omics approaches. Springer

2020-04-02T00:00:00Z The use of green remediation technologies (i.e., phytoremediation, bioremediation, mycoremediation) for the restoration of hydrocarbon-contaminated sites is one of the keys for sustainable development. These technologies rely on the joint action of biotic components of the ecosystem, namely, plants, bacteria, and fungi. Despite the fact that previous studies showed that the clean-up of hydrocarbons could be achieved individually by plants or microorganisms, present investigations suggest that the interaction of plants with their surrounding microbiome determines the outcomes of green remediation technologies. This book chapter reviews the state of the art to explain the two-way relationship established between plants and their associated microbiome in hydrocarbon-polluted soils. Special focus is put on stressing the results obtained in recent studies that employ omics approaches. Wolcan, Silvia María http://sedici.unlp.edu.ar:80/handle/10915/143439 2022-10-06T20:03:57Z 2004-01-01T00:00:00Z

Articulo Australasian Plant Pathology; vol. 33, no. 1 Podosphaera balsaminae was recorded for the first time in Argentina and apparently in the Americas, causing powdery mildew on Impatiens balsamina (balsam) and Impatiens × hawkeri (New Guinea impatiens). This is also the first record of P. balsaminae on New Guinea impatiens. In a preliminary test, results of cross inoculations suggest that a pathogenic specialisation of P. balsaminae for these two hosts is present.

2004-01-01T00:00:00Z Podosphaera balsaminae was recorded for the first time in Argentina and apparently in the Americas, causing powdery mildew on Impatiens balsamina (balsam) and Impatiens × hawkeri (New Guinea impatiens). This is also the first record of P. balsaminae on New Guinea impatiens. In a preliminary test, results of cross inoculations suggest that a pathogenic specialisation of P. balsaminae for these two hosts is present. Villalpando, María Candela Murillo, Bruno Zapata, Silvia Raquel Guerrero, Elisa Evangelina Fernanda Mónaco, Cecilia Inés http://sedici.unlp.edu.ar:80/handle/10915/141726 2023-06-27T19:44:22Z 2016-01-01T00:00:00Z

Articulo Avances en Energías Renovables y Medio Ambiente; vol. 20 En el contexto de una agricultura sustentable el uso de los biocontroladores en el manejo sanitario de plagas es una herramienta muy importante para disminuir la aplicación de agroquímicos que resultan perjudiciales para la salud humana y el medio ambiente. Bajo esta perspectiva este trabajo evaluó en condiciones de laboratorio la capacidad antagonista de aislamientos nativos de <i>Trichoderma</i> sp. frente al hongo fitopatógeno <i>Botrytis cinerea</i>. Para ello se trabajó con 11 cepas sobre las que se evaluó competencia por sustrato, hiperparasitismo, y accionar <i>in situ</i> y a distancia a través de la producción de metabolitos. Todas las cepas evaluadas mostraron capacidad inhibitoria sobresaliendo Cepa cátedra por su mejor accionar conjunto.; In sustentable agriculture context, to work with biocontrol agents in pest management is a very important tool to reduce the application quantity of agrochemicals which are harmful to human health and environment. This work evaluated, in laboratory, antagonistic capacity of Trichoderma sp wild strain against Botrytis cinerea fungus. Eleven strains were proved by substrate competition, hyperparasitism, and <i>in situ</i> and at distance activity trought metabolites production. All strains tested showed inhibitory capacity standing out for its best behavior Cepa cátedra.

2016-01-01T00:00:00Z En el contexto de una agricultura sustentable el uso de los biocontroladores en el manejo sanitario de plagas es una herramienta muy importante para disminuir la aplicación de agroquímicos que resultan perjudiciales para la salud humana y el medio ambiente. Bajo esta perspectiva este trabajo evaluó en condiciones de laboratorio la capacidad antagonista de aislamientos nativos de <i>Trichoderma</i> sp. frente al hongo fitopatógeno <i>Botrytis cinerea</i>. Para ello se trabajó con 11 cepas sobre las que se evaluó competencia por sustrato, hiperparasitismo, y accionar <i>in situ</i> y a distancia a través de la producción de metabolitos. Todas las cepas evaluadas mostraron capacidad inhibitoria sobresaliendo Cepa cátedra por su mejor accionar conjunto. In sustentable agriculture context, to work with biocontrol agents in pest management is a very important tool to reduce the application quantity of agrochemicals which are harmful to human health and environment. This work evaluated, in laboratory, antagonistic capacity of Trichoderma sp wild strain against Botrytis cinerea fungus. Eleven strains were proved by substrate competition, hyperparasitism, and <i>in situ</i> and at distance activity trought metabolites production. All strains tested showed inhibitory capacity standing out for its best behavior Cepa cátedra. Larrán, Silvina Perelló, Analía Edith Simón, María Rosa Moreno, María Virginia http://sedici.unlp.edu.ar:80/handle/10915/141438 2022-09-01T20:04:21Z 2002-10-01T00:00:00Z

Articulo World Journal of Microbiology and Biotechnology; vol. 18, no. 7 The present investigation was undertaken in order to select the surface-sterilization technique most efficient for eliminating epiphytes, to document the spectrum of endophytes of healthy leaves from three wheat cultivars in Buenos Aires Province (Argentina) and to determine their infection frequencies at three growth stages. Surface-sterilization with undiluted commercial solution of sodium hypochlorite was reaffirmed as adequate for removing epiphytes on wheat leaves. From the 450 wheat leaf segments incubated, three bacterial isolates and 130 fungal isolates were obtained. From all the isolates, 19 fungal species were identified. Bacterial isolates were characterized as <i>Bacillus</i> sp. There were significant differences between microorganisms, stages of growth, and stages × microorganisms interaction. Differences between cultivars, stages × cultivars, microorganisms × cultivars and for the triple interaction were not significant. Frequency of microorganisms isolated increased with crop age, but it was statistically similar for the three wheat cultivars tested (Klein Centauro, Klein Dragon and Buck Ombu). <i>Rhodotorula rubra</i>, <i>Alternaria alternata</i>, <i>Cladosporium herbarum</i> and <i>Epicoccum nigrum</i> were isolated in the highest frequency. The other microorganisms were present at intermediate or low values. The species isolated may be assigned to three groups: (a) well-known and economically important pathogens of wheat, (b) commonly abundant phylloplane fungi considered to be primary saprobic and minor pathogens and (c) species occasionally present in wheat.

2002-10-01T00:00:00Z The present investigation was undertaken in order to select the surface-sterilization technique most efficient for eliminating epiphytes, to document the spectrum of endophytes of healthy leaves from three wheat cultivars in Buenos Aires Province (Argentina) and to determine their infection frequencies at three growth stages. Surface-sterilization with undiluted commercial solution of sodium hypochlorite was reaffirmed as adequate for removing epiphytes on wheat leaves. From the 450 wheat leaf segments incubated, three bacterial isolates and 130 fungal isolates were obtained. From all the isolates, 19 fungal species were identified. Bacterial isolates were characterized as <i>Bacillus</i> sp. There were significant differences between microorganisms, stages of growth, and stages × microorganisms interaction. Differences between cultivars, stages × cultivars, microorganisms × cultivars and for the triple interaction were not significant. Frequency of microorganisms isolated increased with crop age, but it was statistically similar for the three wheat cultivars tested (Klein Centauro, Klein Dragon and Buck Ombu). <i>Rhodotorula rubra</i>, <i>Alternaria alternata</i>, <i>Cladosporium herbarum</i> and <i>Epicoccum nigrum</i> were isolated in the highest frequency. The other microorganisms were present at intermediate or low values. The species isolated may be assigned to three groups: (a) well-known and economically important pathogens of wheat, (b) commonly abundant phylloplane fungi considered to be primary saprobic and minor pathogens and (c) species occasionally present in wheat. Wolcan, Silvia María Sato, Y. http://sedici.unlp.edu.ar:80/handle/10915/140832 2022-08-22T20:04:18Z 2005-01-01T00:00:00Z

Articulo Australasian Plant Pathology; vol. 34, no. 4 Powdery mildew of Chamaelaucium uncinatum, caused by Oidiopsis sp., is recorded for the first time in Argentina. Although the teleomophic stage was not found, the characteristics of the fungus were similar to those of the anamorph of Leveillula taurica and might be identified as Oidiopsis sicula. Other than Australia, the centre of origin of this host, this is the first country where this disease has been reported. Descriptions of the symptoms and the pathogen are provided.

2005-01-01T00:00:00Z Powdery mildew of Chamaelaucium uncinatum, caused by Oidiopsis sp., is recorded for the first time in Argentina. Although the teleomophic stage was not found, the characteristics of the fungus were similar to those of the anamorph of Leveillula taurica and might be identified as Oidiopsis sicula. Other than Australia, the centre of origin of this host, this is the first country where this disease has been reported. Descriptions of the symptoms and the pathogen are provided.