439 research outputs found
Epidemiología y variabilidad patogénica del virus del mosaico del pepino dulce (Pepino mosaic virus). Nuevas enfermedades asociadas a su presencia (torrao o cribado)
El Pepino mosaic virus (PepMV) es un Potexvirus que fue descrito por primera vez en pepino dulce (Solanum muricatum Ait.) en Perú (Jones et. Al., 1980). En 1999 se detectó en Holanda, infectando a tomate (Van der Vlugt et al., 2000) mostrando una variada sintomatología. Desde entonces, el PepMV se ha expandido rápidamente por las principales áreas productoras de tomate del Mundo. Este virus se ha convertido en uno de los principales problemas en la producción de tomate en Europa donde produce importantes pérdidas económicas.
La rápida expansión del PepMV en las zonas afectadas ha estado facilitada por su eficaz transmisión mecánica con las operaciones de cultivo y mediante los insectos polinizadores (Lacasa et al., 2003), sin embargo no se ha detectado la existencia de ninguna especie de insecto capaz de actuar como vector del mismo. El PepMV podría permaneces en el campo de una cosecha a la siguiente infectando a la flora arvense que podría actuar como reservorio de la enfermedad. Asimismo se ha comprobado la transmisión por semilla que podría constituir la forma de dispersión del virus a la larga distancia (Córdoba et. A., 2007).
Actualmente se conocen diferentes aislados del virus que afectan al tomate. En primer momento, debido a las diferencias biológicas y moleculares observadas entre el aislado del PepMV que infectaba a tomate y el original de pepino dulce, distintos autores consideraron el aislado de tomate como un aislado diferente, denominándolo aislado tipo tomate (Van der Vlugt y Beredsen, 2002). Estudios posteriores demostraron que los aislados de PepMV de Europa, América del Norte y Canadá comparados con el aislado original de pepino dulce presentaban diferencias evidentes en sintomología, así como estructura poblacional del PepMV en cultivo de tomate en España, analizando y secuenciando tres zonas distintas del genoma del virus.Alfaro Fernández, AO. (2009). Epidemiología y variabilidad patogénica del virus del mosaico del pepino dulce (Pepino mosaic virus). Nuevas enfermedades asociadas a su presencia (torrao o cribado) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/7027Palanci
Seed transmission of Pepino Mosaic Virus an efficacy of the tomato seed disinfection treatments
[EN] Rates of seed transmission for Pepino mosaic virus (PepMV) were estimated in seedlings grown from seeds obtained from symptomatic tomato (Lycopersicon esculentum) fruits of plants naturally infected with the virus. The proportion of seeds infected with PepMV was at least 25% as estimated from enzyme-linked inummosorbent assay (ELISA) analysis of grouped seeds. The seeds from symptomatic fruits were planted, and seedlings at the cotyledon and transplant stage were assayed for PepMV by ELISA. Three of 168 seedlings grown from infected seeds were PepMV-positive, corresponding to a seed-to-seedling transmission rate of 1.84%. Various tomato seed treatments were evaluated for their ability to prevent seed transmission of PepMV. This virus was largely eradicated by immersing the seeds in 10% trisodium phosphate for 3 h. Although heat treatments of 24 h at 80 degrees C and 48 h at 74 degrees C eliminated PepMV in seedlings, these treatments did not eradicate the virus in whole seeds. The three treatments did not adversely affect seed germination. The results suggest that trisodium phosphate can be used to eradicate PepMV in tomato seed without hindering germination.Córdoba-Sellés, MDC.; García-Rández, A.; Alfaro Fernández, AO.; Jordá-Gutiérrez, C. (2007). Seed transmission of Pepino Mosaic Virus an efficacy of the tomato seed disinfection treatments. Plant Disease. 91(10):1250-1254. https://doi.org/10.1094/PDIS-91-10-125012501254911
Haplotypes of "Candidatus Liberibacter solanacearum" identified in Umbeliferous crops in Spain
[EN] 'Candidatus Liberibacter solanacearum' is a phloem-limited Gram-negative bacterium that causes serious damage to different crops of the botanical families Solanaceae and Apiaceae. Five haplotypes have been described: LsoA and LsoB are present in solanaceous crops in America and vectored by the tomato/potato psyllid Bactericera cockerelli; LsoC affects carrots from Northern and Central Europe, and is transmitted by the carrot psyllid Trioza apicalis; haplotypes LsoD and LsoE are present in Southern Europe and Morocco in carrot and celery, and are associated with the psyllid Bactericera trigonica. Thirty-four 'Ca. L. solanacearum' isolates were collected in six different regions of Spain from distinct Apiaceae hosts (carrot, celery, parsley and parsnip) in eight consecutive years and were analysed. Their haplotypes were determined by a sequence analysis of 16S ribosomal RNA, the 16S-26S ribosomal RNA intergenic spacer, and the 23S ribosomal RNA and rplJ and rplL genes. Both haplotypes LsoD and LsoE were found across Spain, and no host specificity appeared between these two haplotypes. This is the first report of 'Ca. L. solanacearum' associated with parsley and parsnip.This work has been supported by grant INIA (RTA2011-00142). This paper is dedicated to the memory of F.J. Villaescusa (1981-2011). The technical support of S. Sanjuan and J.C. Ferrandiz from Agricola Villena Coop. V. is also acknowledged.Alfaro Fernández, AO.; Hernández-Llopis, D.; Font San Ambrosio, MI. (2017). Haplotypes of "Candidatus Liberibacter solanacearum" identified in Umbeliferous crops in Spain. European Journal of Plant Pathology. 149(1):127-131. https://doi.org/10.1007/s10658-017-1172-21271311491Alfaro-Fernández A., Cebrián M.C., Villaescusa F.J., Hermoso de Mendoza A., Ferrándiz J.C., Sanjuán S., Font M.I. (2012). ‘Candidatus Liberibacter solanacearum’ associated with Bactericera trigonica affected carrots in the Canary Islands. Plant Disease 96, 581.Bertolini, E., Teresani, G. R., Loiseau, M., Tanaka, F. A. O., Barbé, S., Martínez, C., Gentit, P., López, M. M., & Cambra, M. (2014). Transmission of ‘Candidatus Liberibacter solanacearum’ in carrot seeds. Plant Pathology, 64, 276–285.EPPO. (2013). Data sheets on pests recommended for regulation. Candidatus Liberibacter solanacearum. EPPO Bulletin, 43, 197–201.Green, M. J., Thompson, D. A., & Mackenzie, D. J. (1999). Easy and efficient DNA extraction from woody plants for the detection of phytoplasmas by polymerase chain reaction. Plant Disease, 83, 482–485.Hansen, A. K., Trumble, J. T., Stouthamer, R., & Paine, T. D. (2008). A new huanglongbing species, “Candidatus Liberibacter psyllaurous,” found to infect tomato and potato, is vectored by the psyllid Bactericera cockerelli (Sulc). Applied Environmental Microbiology, 74, 5862–5865.Larkin, M. A., Blackshields, G., Brown, N. P., Chenna, R., McGettigan, P. A., McWilliam, H., Valentin, F., Wallace, I. M., Wilm, A., Lopez, R., Thompson, J. D., Gibson, T. J., & Higgins, D. G. (2007). Clustal W and Clustal X version 2.0. Bioinformatics, 23, 2947–2948.Loiseau, M., Garnier, S., Boirin, V., Merieau, M., Leguay, A., Renaudin, I., Renvoisé, J.-P., & Gentit, P. (2014). First report of ‘Candidatus Liberibacter solanacearum’ in carrot in France. Plant Disease, 98, 839.Munyaneza, J. E. (2012). Zebra chip disease of potato: biology, epidemiology and management. American Journal of Potato Research, 89, 329–350.Munyaneza, J., Buchman, J., Upton, J., Goolsby, J., Crosslin, J., & Bester, G. (2008). Impact of different potato psyllid populations on zebra chip disease incidence, severity, and potato yield. Subtropical Plant Science, 60, 27–37.Munyaneza, J., Sengoda, V., Crosslin, J., de la Rosa-Lorenzo, G., & Sanchez, A. (2009). First report of ‘Candidatus Liberibacter psyllaurous’ in potato tubers with zebra Chip disease in Mexico. Plant Disease, 93, 552.Munyaneza, J. E., Fisher, T. W., Sengoda, V. G., & Garczynski, S. F. (2010a). First report of ‘Candidatus Liberibacter solanacearum’ associated with psyllid-affected carrots in Europe. Plant Disease, 94, 639.Munyaneza, J. E., Fisher, T. W., Sengoda, V. G., Garczynski, S. F., Nissinen, A., & Lemmetty, A. (2010b). Association of ‘Candidatus Liberibacter solanacearum’ with the psyllid Trioza apicalis (hemiptera: Triozidae). Journal of Economic Entomology, 103, 1060–1070.Munyaneza, J. E., Swisher, K. D., Hommes, M., Willhauck, A., Buck, H., & Meadow, R. (2015). First report of ‘Candidatus Liberibacter solanacearum’ associated with psyllid-infested carrots in Germany. Plant Disease, 99, 1269.Nelson, W. R., Fisher, T. W., & Munyaneza, J. E. (2011). Haplotypes of “Candidatus Liberibacter solanacearum” suggest long-standing separation. European Journal of Plant Patholology, 130, 5–12.Nelson, W. R., Sengoda, V. G., Alfaro-Fernández, A., Font, M. I., Crosslin, J. M., & Munyaneza, J. E. (2013). A new haplotype of ‘Candidatus Liberibacter solanacearum’ identified in the Mediterranean region. European Journal of Plant Pathology, 135, 633–639.Tahzima, R., Maes, M., Achbani, E. H., Swisher, K. D., Munyaneza, J. E., & De Jonghe, K. (2014). First report of ‘Candidatus Liberibacter solanacearum’ on carrot in Africa. Plant Disease, 98, 1426.Teresani, G. R., Bertolini, E., Alfaro-Fernández, A., Martínez, C., Tanaka, F. A. O., Kitajima, E. W., Roselló, M., Sanjuán, S., Ferrándiz, J. C., López, M. M., Cambra, M., & Font, M. I. (2014). Association of ‘Candidatus Liberibacter solanacearum’ with a vegetative disorder of celery in Spain and development of a real-time PCR method for its detection. Phytopathology, 104, 804–811.Teresani, G., Hernández, E., Bertolini, E., Siverio, F., Marroquín, C., Molina, J., de Hermoso Mendoza, A., & Cambra, M. (2015). Search for potential vectors of ‘Candidatus Liberibacter solanacearum’: population dynamics in host crops. Spanish Journal of Agricultural Research, 13, e10–002
Virosis en tomate transmitidas por semilla y su control
[ES] Las virosis transmitidas por semilla en el cultivo del tomate crean gran preocupación entre los productores, y son de especial atención en aquellos que se dedican al cultivo de variedades locales donde las semillas se extraen durante la campaña y son empleadas para cultivos posteriores con lo que la infección y dispersión de estos virus es mucho más frecuente. Entre los virus transmitidos por semilla en tomate destacan el virus del mosaico del tomate (ToMV) y el virus del mosaico del pepino dulce (PepMV). Ambos virus se caracterizan por transmitirse, además de por semilla, de manera mecánica fácilmente y son muy estables manteniéndose en los restos del cultivo anterior y en las infraestructuras empleadas durante el manejo del cultivo. Sin embargo, la localización de estos virus en las semillas contaminadas difiere, mientras que PepMV se localiza únicamente de manera superficial, ToMV puede encontrarse además en zonas más internas como en el endospermo. Esto hace que los tratamientos empleados para la desinfección de semillas infectadas con cada uno de estos virus sea distinto: mientras que PepMV puede ser inactivado con tratamientos químicos superficiales, el tratamiento para descontaminar semillas con ToMV debe ser térmico a elevadas temperaturas.[EN] Viral diseases transmitted through seed create a great concern among
the tomato producers, especially those who use local varieties that harvest
their own seeds from the previous growing season fruits. In this case the
infection and spread of seed-transmitted viruses is more usual. ToMV and PepMV are the two main seed-transmitted viruses which affect tomato
crops. Both viruses are easily mechanically and seed transmitted, and
remain infective in the plant debris of the previous crop and in the crop
structures. However, the location of the virus in the contaminated seed is
different. PepMV is present only externally in the seed coat, but ToMV
could be also found in the endosperm. Therefore seed treatments to
inactivate these two viruses are different; while PepMV could be inactivated
by external chemical treatments, ToMV infected seeds should be thermal
treated in order to eliminate further seedling infections.Alfaro Fernández, AO.; Font San Ambrosio, MI. (2020). Virosis en tomate transmitidas por semilla y su control. En I Congrés de la Tomaca Valenciana: La Tomaca Valenciana d'El Perelló. Editorial Universitat Politècnica de València. 97-114. https://doi.org/10.4995/TOMAVAL2017.2017.6524OCS9711
Germination ecology of the perennial Centaurium somedanum, a specialist species of mountain springs
To improve understanding of how a rare endemic species of Centaurium adapts to a specialized ecological niche, we studied the germination ecology of the mountain spring specialist, C. somedanum, a perennial species restricted to an unusual habitat for this genus. We conducted laboratory experiments with fresh seeds collected from two populations for three consecutive years, to investigate: (1) the effect of temperature and light ongermination; (2) the existence of seed dormancy; and (3) inter-population and inter-annual variation in germinability. Germination occurred only in the light and at relatively low temperatures (15?228C) with no differences between constant and alternating regimes, and a significant decrease at high temperatures (258C and 308C). We found non-deep simple morphophysiological dormancy and variation in seed germinability depending on the year of seed collection. C. somedanum diverged from the common germination characteristics of the genus in: (1) its germination at lower temperatures, which contrasts with what is generally expected in wetland species but could be adaptive in the spring habitat; and (2) its morphophysiological dormancy, which we report here for the first time in the genus and which could be an adaptation to its mountain habitat
The integrity of the ocular surface in corneal ulcers: three case report
Las úlceras corneales infecciosas constituyen un importante problema de salud pública. Un tratamiento precoz de
la infección y un correcto control en un segundo tiempo de la inflamación así como del componente neurotróficotóxico iatrogénico, aumenta la probabilidad de un mejor resultado visual final. Presentamos una serie de casos
clínicos de úlceras corneales documentadas fotográficamente, en las que se evidencia su agresividad al diagnóstico y sus secuelas, así como la descripción de su tratamiento en cada caso.Infectious corneal ulcers are a major public health problem. Early treatment of infection and proper control of the
second stage of inflammation and of the iatrogenic neurotrophic-toxic component raise the likelihood of a satisfactory medical outcome. We present a series of photographically-documented clinical cases of corneal ulcers,
illustrating the aggressiveness of the condition and showing the sequels produced, together with a description of
the treatment given in each case
Detección y cuantificación del virus del mosaico de la sandía por RT-PCR a tiempo real
El virus del mosaico de la sandía (watermelon mosaic virus, WMV) produce graves daños en varios cultivos de cucurbitáceas en todo el mundo. El control de enfermedades se basa en restringir la propagación del virus y en la obtención de variedades resistentes por mejora genética. Para poder aplicar estas estrategias de control es necesario disponer de herramientas para
la detección sensible y la cuantificación precisa de WMV en plantas infectadas. En este trabajo, se desarrolló un procedimiento basado en la retrotranscripción seguida de una PCR a tiempo real con un par de iniciadores y una sonda TaqMan® específicos de WMV
Educational project “Mathematics for secondary education (MATEM)”, your academic task during the year 2012: participants´ perspective
MATEM es un proyecto de extensión universitaria. Entre sus objetivos está el mejoramiento de la educación matemática a nivel del ciclo diversificado y, para ello, las universidades estatales trabajan en conjunto con profesores y estudiantes de secundaria. El objetivo de este artículo es mostrar sobre la indagación realizada sobre diversos aspectos del proyecto MATEM, con el fin de evaluar su desarrollo y considerar las recomendaciones para la toma de decisiones. Se resume la percepción de los estudiantes de secundaria inscritos en los cursos Precálculo y Cálculo de MATEM-UNA en el año 2012 y la opinión de los docentes tutores. Se encontró que MATEM es una actividad académica atractiva para los docentes de matemáticas y la población estudiantil de diferentes regiones del país, aunque en ocasiones no se cuente con las condiciones necesarias para desarrollarlo en sus respectivas instituciones. El reconocimiento de un curso universitario, obtener más práctica para la prueba de bachillerato, aumentar sus conocimientos en matemática y prepararse para los cursos universitarios constituyen los aspectos que más motivan a los estudiantes a inscribirse en el proyecto. Al respecto, el desarrollo de habilidades y destrezas de razonamiento resultó el mencionado con mayor frecuencia por los entrevistados."MATEM" is a university outreach project. Among its objectives is to improve the mathematics education at the high school level and to accomplish it public universities work together with high school´s teachers and students. The study´s aim was to research various aspects of MATEM Project to order to evaluate its development and consider recommendations for making decisions. This paper summarizes the perceptions of high school students enrolled during 2012 in courses Precalculus and Calculus, moreover the opinion of mathematics teachers. The main results were that MATEM is an academic activity attractive for math teachers and student population from different regions of the country, although sometimes are not available the necessary conditions to develop it in their respective institutions, to have passed a university course, get more practice for the standard test at the end of high school, increase their math skills and prepare for college courses were the aspects that motivate students to enroll in the project, however the development of reasoning skills and abilities were more frequently pointed by respondents
Keratograph 5M As A Useful And Objective Tool For Evaluating The Ocular Surface In Limbal Stem Cell Deficiency.
Purpose: In limbal stem cell deficiency, both the Ocular Surface Disease Index (OSDI)
questionnaire and tear break-up time (BUT) are comparable between traditional methods and
the Keratograph 5M. In this study, we aimed to correlate OSDI with Keratograph 5M
interviewed OSDI, as well as slit-lamp tear BUT with Keratograph 5M noninvasive tear
break-up time (NIKBUT) in limbal stem cell deficiency.
Patients and methods: Thirty-eight limbal stem cell-deficiency patients (76 eyes) from
Virgen Macarena-Rocio Hospital (Seville, Spain) underwent this diagnostic test study. All
patients completed the traditional OSDI. We measured the BUT, performed a Keratograph
5M analysis of NIKBUT first (employed for the analysis) followed by the average NIKBUT,
the level of dryness, and conducted the OSDI questionnaire through an interview. For each
pair of tests, we analyzed the means and applied an intraclass correlation coefficient (r),
creating a Bland-Altman plot for data dispersion.
Results: Average values were 47.5 points (±25.8), and 47.3 points (±27.5) for traditional
OSDI and Keratograph OSDI, respectively (P =0.87); the r value indicates good agreement
(0.72). The Bland-Altman plot followed a linear pattern, and the results were similarly
distributed. The NIKBUT mean was shorter than the BUT mean (P = 0.007); the r value
indicates moderate agreement (0.574). The Bland-Altman plot formed an almost horizontal
line, with almost all values between the mean and two standard deviations.
Conclusion: Keratograph 5M is useful for the evaluation of the ocular surface in limbal
stem cell deficiency. NIKBUT can substitute BUT based on its advantages of being non-
invasive, objective, with intraobserver and interobserver repeatability and reliability. The
Keratograph 5M OSDI is comparable to the traditional questionnaire.Unión Europea RD16/0008/001
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