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The aim of this work was to characterize cultural, morphological, physiological and molecular endospore forming endophytic bacteria associated with Theobroma cacao L. in Quinindé canton, Esmeraldas province, Ecuador. Isolation of bacteria was done from healthy pods and flower pedicels from cocoa Criollo Type Nacional cultivar. Bacteria isolates were characterized cultural, morphological, physiological and molecular. Identification of bacteria isolates were analyzed by 16S-ribosomal RNA gene pyrosequencing. Fourty-five endospore forming endophytic bacteria were recovered from healthy pods and flowers peduncules, mainly from endocarp. Based on their cultural, morphological and physiological characteristics they were similar to Bacillus. According to 16S rDNA sequence alignment isolates were classified like Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus mycoides and Bacillus cereus with 99 % sequence similarity. Some bacteria isolates did not produced optimal concensus sequences and were classified under the genus Bacillus. [ABSTRACT FROM AUTHOR]

The aim of this work was to determine the antifungal activity of Bacillus subtilis 9-2, Bacillus mycoides 29-2, Bacillus sp. 33 and 72, Bacillus cereus 45-1, 51-2, 53-4 and Bacillus amyloliquefaciens 24 on mycelial growth and sporulation of the phytopathogenic fungus Moniliophthora roreri H.C Evans et al. The confrontation experiments were carried out in Petri dishes with two compartments. PDA culture medium was added to one side of the plate and TSA to the other. The bacterial strains were individually inoculated (100 µl; 1×108 CFU ml-1) on the face of the cap with TSA culture medium; while on the other lid with PDA culture medium, a mycelial disk (5 mm in diameter) of the strain of the phytopathogenic fungus was placed. Sterile distilled water was used as a control. All plates were sealed with Parafilm and incubated at 28°C for 15 days. The experiments were repeated twice. All strains of bacteria produced volatile compounds that inhibited mycelial growth and the formation of M. roreri spores. B. subtilis 9-2, B. mycoides 29-2, B. sp. 33, Bacillus cereus 45-1, 51-2 and Bacillus amyloliquefaciens 24 inhibited mycelial growth and sporulation of M. roreri by more than 60%. These findings offer new possibilities to control frosty pod rot caused by M. roreri using Bacillus endophytes strains producing antifungal volatile compounds. [ABSTRACT FROM AUTHOR]

The aim of this work was to determine the antagonistic effect of the endophytic endosporeforming bacteria against M. roreri, as well as its identification. The trial was carried out by dual culture method on Petri dishes containing Potato Dextrose Agar culture medium (PDA). The bacterial inoculum was placed in the center of the plate, and discs of the pathogenic fungus were placed on both sides of the plate. M. roreri colony growth was measured and the radial growth inhibition percentage (RGIP) was calculated at 15 days. A completely randomized design was used with five replicates per treatment (isolate from endophytic bacteria) and control (M. roreri). Besides, bacteria were characterized from the cultural, morphological and physiological point of view according to methodologies collected in the scientific literature. In the antagonism test, 23 isolates of the bacteria (51.1 %) showed a RGIP in the pathogen ranging from 53.8 to 73.8 %; while 22 isolates (48.9 %) registered a RGIP between 2.8 and 47.2 %, at 15 days of incubation in the interaction. The description of the bacterial isolates based on their cultural and morpho-physiological characteristics confirmed their taxonomic location in the group of the aerobic endospore-forming bacteria, class Bacilli. It is demonstrated the high potential of new strains of Bacillus spp. as promising candidates for the biological control of M. roreri, which is the causal agent of frosty pod rot. [ABSTRACT FROM AUTHOR]

El presente trabajo se realizó con el objetivo de actualizar el estado de información existente sobre los microorganismos endófitos asociados a Theobroma cacao L. como agentes de control biológico de la moniliasis, causada por Moniliophthora roreri Evans et al. Se resume sobre el origen y evolución de las definiciones de microorganismos endófitos, enfatizando en el control biológico de las enfermedades del cacao con énfasis en la moniliasis, uno de los problemas fitosanitarios de mayor importancia a nivel mundial; así como se hace una valoración sobre sus perspectivas de empleo. Los hongos y bacterias endófitos presentan varios mecanismos de acción entre los que se encuentran: competencia directa por el espacio y nutrientes, antibiosis, micoparasitismo, resistencia sistémica inducida y promoción del crecimiento; funciones que son parte de las estrategias para el manejo eficaz y sostenible de la moniliasis. The present work was carried out with the objective of updating the state of existing information on the endophytic microorganisms associated with Theobroma cacao L., as agents of biological control of moniliasis, caused by Moniliophthora roreri Evans et al. It is summarized on the origin and evolution of the definitions of endophytic microorganisms, emphasizing the biological control of cocoa diseases with emphasis on moniliasis, one of the most important phytosanitary problems worldwide; as well as an assessment of their employment prospects. Fungal and bacterial endophytes have several mechanisms of action, which include direct competition for space and nutrients, antibiosis, mycoparasitism, induced systemic resistance and promotion of growth; functions that are part of the strategies for an effective and sustainable management of the frosty pod rot. [ABSTRACT FROM AUTHOR]

With the objective to evaluate the antagonistic activity of T. harzianum (strain A-34) on the causal agent of rice blast (P. grisea), were developed several in vitro experiments. It was evaluated the biocontrol mechanisms such as competition through mounted the percent inhibition of radial growth of hyphae of P. grisea from 24 to 240 hours and the antagonistic capacity. In addition, was evaluated micoparasitism to inclination the observation of events Microscopy winding, penetration, vacuolization, lysis, and antibiosis by observing 24 hours a confrontation between the hyphae of the phytopathogenic fungus and biological control agent. It was obtained at 120 hours 100 % inhibition of micelial growth of causal agent, what corresponded with the degree 1 of antagonistic capacity (scale) and is recorded as a hyperparasitic action on P. grisea. It was evidenced an antibiotic effect of metabolites produced by T. harzianum (strain A-34) to 24 hours of confrontation, where there was time interaction between the hyphae of microorganisms with 14,3 % inhibition, also was evidence the micoparasitism events by penetration, vacuolization and lysis in the cells of phytopathogenic fungus. These results demonstrated the ability of T. harzianum (strain A-34) on causal agent of rice blast (P. grisea). [ABSTRACT FROM AUTHOR]

In order to evaluate the antifungal activity of Spathodea aqueous extracts, as a viable alternative for the control of bean rust, this work was realize in an field independent farmer in Corralillo municipality, Villa Clara province, between January and May 2014. For this, aqueous extracts from leaves and flowers were applied at 5 and 10% on BAT-304 bean variety. The experiment was made under a design of random blocks with six treatments and three replications. The extract applications began from 30 days of age (flowering) and the last 65 days, with a frequency of five days. It was objetive determining the infection intensity and rust distribution in each one of the treatments as well as their effect on quantitative variables (number of pustules/ leaf, pustules diameter and yield. As results was found that the aqueous extracts of leaves and flowers of S. campanulata, showed antifungal activity against Uromyces phaseoli applied at 10%. [ABSTRACT FROM AUTHOR]

This work was developed at Agriculture Microbiology laboratory in the Agriculture Faculty at Universidad Central “Martha Abreu" de Las Villas, with the aim to evaluate the influence of incubation time of Trichoderma harzianum Rifai on antifungal activity of its culture filtrates against Bipolaris oryzae. Flask with Czapek broth was used for growing T. harzianum, then one disc of mycelium were incubated during 20 and 30 days at 28±1ºC and dark. Trichoderma harzianum (strain A-34) was submited to filtration process, and comparison were done among concentration of 0%, 25%, 50%, 75%, 100% (v/v). Major inhibition porcentaje were observed in concentrations of 75% y 100% both at 20 and 30 days of incubation. At 20 day the inhibition porcentaje was greater in comparsison with 30 days. [ABSTRACT FROM AUTHOR]

El artículo discurre sobre el estudio de tres patógenos fungosos en tres variedades de soya. Los autores comentan sobre las enfermedades provocadas por hongos fitopatógenos del suelo en el que se cultiva la soya. También se considera la presencia de Rhizoctonia, un tipo de fungo.

La aplicación de metabolitos o filtrados de microrganismos antagonistas es una alternativa ecológica que ha sido poco estudiada para el control del agente causal de tizón del arroz M. grisea. El siguiente trabajo se realizó con el objetivo de evaluar el efecto del tiempo de incubación, el medio y el tipo de cultivo en la obtención de filtrados de cultivo de T. harzianum sobre el agente causal del tizón del arroz M. grisea en el laboratorio de microbiología agrícola de la Facultad de Ciencias Agropecuarias de la Universidad Central de Las Villas, Cuba. Se estudiaron los tiempos de incubación de 10, 20 y 30 días, los medios de cultivo Caldo de Papa Glucosado, Czapek, Richard y Fries, así como las condiciones de cultivo de estático y agitado. Los filtrados obtenidos bajo estas condiciones se sometieron a las siguientes concentraciones: 25, 50, 75% y al 100%. Se evaluó el Porcentaje de Inhibición del Crecimiento Radial del agente causal a las 24, 72, 120 y 168 horas. En todos los factores estudiados se obtuvo inhibición del crecimiento de los micelios de M. grisea en un rango de 30% a 80% a las concentraciones de 75% y 100%. [ABSTRACT FROM AUTHOR]

Con el objetivo de seleccionar cepas de actinomicetos eficientes como agentes biocontroladores de los hongos fitopatógenos del suelo Rhizoctonia solani Kühn., Sclerotium rolfsii Sacc. y Macrophomina phaseolina (Tassi) Goid., se evaluaron 69 cepas de actinomicetos, a las cuales se le determinó la actividad antagonista in vitro contra los hongos fitopatógenos del suelo. Posteriormente, se realizó una selección de las cepas con mejor capacidad antagónica para la evaluación de la actividad enzimática extracelular, la capacidad solubilizadora de fosfatos, la producción de ácido indol-acético (AIA) y la caracterización molecular. De las 69 cepas evaluadas, se obtuvo que 2 cepas presentaron antagonismo contra S. rolfsii, 39 contra M. phaseolina y 11 contra R. solani. Las cepas que presentaron los mayores halos de inhibición contra R. solani fueron J11, J4 y EA2, y contra M. phaseolina la cepa EBa21. Todas las cepas seleccionadas presentaron actividad enzimática extracelular; se destacan la cepa EBa21 en la producción de quitinasas, las cepas EA2, J4 y L2 en la de celulasas y las cepas EA2 y B8 en las de proteasas. En la solubilización de fosfato sobresalieron las cepas B8 y EBa21, mientras que en la producción de AIA prevalecieron las cepas EBe3, EA2 y EBa21. La identificación de las cepas, mediante la secuenciación de la región 16S del ARNr, arrojó que todas tienen una homología del 99% con diferentes especies de Streptomyces. spa [ABSTRACT FROM AUTHOR]

El artículo presenta un resumen de la tesis de doctorado en Ciencias Agrícolas, que expone un análisis sobre el cultivo de tomate (Lycopersicon esculentum Mill), el cual constituye la especie principal que comporta un sistema de cultivo protegido en Cuba.

Bipolaris oryzae and Sarocladium oryzae are the principal causal agents of rice disease in Cuba. The aim of this work, was to determine antagonic activity of Trichoderma harzianum against B. oryzae and S. oryzae isolated from Camagüey. Exposition time and interactions amongs T. harzianum and the fungal causal agents. Also antagonic mechanisms (micoparasitism, competence and antibiosis) were evaluated. At 48 hours hyphal interaction between B. oryzae and T. harzianum were determined. Hyphal Coiling, penetration, lysis and vacuolization on parasited B. oryzae were observed. At 240 hours, hiperparasite activity of antagonist showed total colonization of mycelial of B. oryzae with 67.10% growth inhibition. In the case of S. oryzae, growth inhibition was 64.4% with 75% of colonozation of total surface of Petri dish. Antibiosis was observed in both fungal causal agents at 24 hours. Non differences were determined in the competence and antibiosis mechanism among antagonist-fungal causal agents interactions. fúngicas del arroz. Evaluation of “in vitro" antagonism of Trichoderma harzianum against B. oryzae and S. oryzae could be a promising alternative for a sustainable management of the principal causal agents of rice disease in production areas of Cuba. [ABSTRACT FROM AUTHOR]

The effect of seed treatment with the actinomycetes strains EA2 and CB14, and their combination, on damping-off incidence caused by Rhizoctonia solani Kühn in Phaseolus vulgaris L. cv. Velasco largo was evaluated under greenhouse conditions. These strains were compared with Trichoderma harzianum A-34, Celest®Top 312 FS and two controls (positive and negative). Inceptisol sterile and non-sterile soil was used under a completely randomized design. The coating seeds with strains were made using 8 % cassava starch. The incidence of R. solani was determined 21 days after sowing. In non-sterile soil, the lowest incidences caused by R. solani were found with Celest®Top 312 FS, which did not significantly differ from the combination of actinomycete strains CB14 + EA2, but yes with the rest of the treatments. In the sterile soil, the lowest percentages of incidences were obtained with the combination of actinomycete strains (CB14 + EA2). [ABSTRACT FROM AUTHOR]

Malanga (Xanthosoma sagittifolium (L.) Schott) is an important food crop for over 400 million people in the tropics and subtropics. In order to determine the response of different varieties of malanga Xanthosoma to dry rot, a series of experiments were conducted in the period between 2012 and 2014. The experiments were performed on loamy Soil at the National Research Institute in Tropical Crops and Roots (INIVIT). We determined the incidence and severity of damage, yields and percent of losses at harvest. The lowest values of incidence and the highest total return was achieved in clons 'INIVIT MX-95-2', 'INIVIT MX-95-1' and 'INIVIT MX-2007'. Clones of malanga Xanthosoma belonging to the group purple, showed lower incidence that of white and yellow groups. These results will allow selecting cultivars of malanga with greater resistance to the dry rot and with this to diminish the losses in the harvest. [ABSTRACT FROM AUTHOR]

Con el objetivo de evaluar los mecanismos de acción de T. harzianum sobre M. grisea se utilizó la técnica de cultivo dual. El mecanismo de acción de competencia se determinó a través del Porcentaje de Inhibición del Crecimiento Radial (PICR). La antibiosis se comprobó a las 24 horas a través del porcentaje de inhibición cuando no existía interacción entre las hifas de los agentes biológicos y el mecanismo de micoparasitismo a partir del contacto de las hifas del antagonista con el hongo patógeno. Desde las 96 horas, se obtuvo un PICR por encima del 93,0% de inhibición del crecimiento de las hifas de M. grisea. Además, se evidenció un hiperparasitismo del agente antagonista al presentar un sobrecrecimiento con la producción de conidios sobre el patógeno. A las 24 horas se alcanzó 14,3% de inhibición del crecimiento micelial de M. grisea, lo que demuestra la producción de metabolitos volátiles y no volátiles por el agente de control biológico y se observó micoparasitismo por enrollamiento, penetración, vacuolización y lisis. [ABSTRACT FROM AUTHOR]