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Caracterización morfóliga y molecular de Nematodos fitoparasíticos asociados con tomate riñón (Solanum lycopersicum L.): estrategias de control en Meloidogyne sp.
No full textABSTRACT
Root root-knot nematodes belonging to the genus Meloidogyne are widely distributed worldwide and they are considered the most important phytopathogens due to their impact on economic importance crops. In the present study, morphometric variations of populations of Meloidogyne sp. collected in different localities from provinces of Cotopaxi and Tungurahua. Additionally, the effect of different doses (1, 2 and 3%) of essential oils of Nicotiana glauca, Ricinus comunis and Brassica carinata for the control of Meloidogyne spp was evaluated. A negative control (tween) and a positive control (Nakar nematicide 1.5 ml/L) were used. Samplings were made in farms planted with tomato in El Tambo, Cunchibamba, Quillan Loma and Izamba (Province of Tungurahua) and in Patain, Rumipamba, Salache, and Santa Ana (Province of Cotopaxi). The extraction of the nematodes was done by using the Baermann funnel. The morphometric data were subjected to a Principal Components Analysis (PCA) to determine the interpopulation variations. A wide variation of the morphometric variables was observed in the juveniles (J2) of the different populations of Meloidogyne sp. collected in Cotopaxi, mainly regarding the length of the body, width in the middle part, length of the stylet and b, while in the populations collected in Tungurahua the populations showed to be similar between them. The Principal Components Analysis explained up to 80.7% of the variation when considering the first three axes and indicated that the variables tail length, esophagus length and width in the middle part of the body had the highest weights to explain this variation. The mortality rate produced by the essential oils increased with the increase of the dose and time of exposure, with the best results when N. glauca oil was used at doses of 2 and 3%, followed by the oil of B. carinata. Based on the effectiveness of thes two essential oils, they could be incorporated into pest management programs against Meloidogyne population, however, field studies are suggested to validate the results under laboratory conditions. In this study molecular characterization was not made due to lack of equipments and time to standardization of the methodology.RESUMEN
Los nematodos agalladores de raíces del género Meloidogyne están ampliamente distribuidos a nivel mundial y son considerados los fitopatógenos más importantes debido a su impacto impacto en cultivos de importancia económica. En el presente estudio se evaluaron las variaciones morfométricas de poblaciones de Meloidogyne sp. colectadas en diferentes localidades de las provincias de Cotopaxi y Tungurahua. Adicionalmente se evaluó el efecto de diferentes dosis (1, 2 y 3%) de aceites esenciales de Nicotiana glauca, Ricinus comunis y Brassica carinata para el control de Meloidogyne spp. Se usó un testigo negativo (tween) y uno positivo (nematicida Nakar 1,5 ml/L). Los muestreos fueron hechos fincas sembradas con tomate riñón en El Tambo, Cunchibamba, Quillan Loma e Izamba (Provincia de Tungurahua) y en Patain, Rumipamba, Salache, y Santa Ana (Provincia de Cotopaxi). La extracción de los nematodos fue hecha mediante el uso del embudo de Baermann. Los datos mosrfométricos fueron sometidos a un análisis de Componentes Principales (ACP) para determinar las variaciones interpoblacionales. Se observó una amplia variación de las variables morfométricas en los juveniles (J2) de las diferentes poblaciones de Meloidogyne sp. Colectadas en Cotopaxi, principalmente en cuanto a la longitud del cuerpo, ancho en la parte media, longitud del estilete y b, mientras que en las poblaciones colectadas en Tungurahua las poblaciones mostraron más similitud entre ellas. El Análisis de Componentes Principales explico hasta un 80,7% de la variación al considerar los tres primeros ejes e indicó que las variables longitud de la cola, longitud del esófago y ancho en la parte media del cuerpo tuvieron los mayores pesos para explicar esta variación. La tasa de mortalidad producida por los diferentes aceites incrementó con el aumento de la dosis y tiempo de exposición, con los mejores resultados cuando se usó aceite de N. glauca a dosis de 2 y 3%, seguido del aceite de B. carinata. Basados en la efectividad de estos aceites esenciales, estos podrían ser incorporados en programas de manejo de poblaciones de Meloidogyne, sin embargo se sugiere realizar estudios de campo para validar los resultados en condiciones de laboratorio. En el presente estudio no se ha trabajado la caracterización molecular por motivo que no se tiene los equipos y limitación de tiempo para la estandarización de la metodología.Tesi
Caracterización morfóliga y molecular de Nematodos fitoparasíticos asociados con tomate riñón (Solanum lycopersicum L.): estrategias de control en Meloidogyne sp.
No full textABSTRACT
Root root-knot nematodes belonging to the genus Meloidogyne are widely distributed worldwide and they are considered the most important phytopathogens due to their impact on economic importance crops. In the present study, morphometric variations of populations of Meloidogyne sp. collected in different localities from provinces of Cotopaxi and Tungurahua. Additionally, the effect of different doses (1, 2 and 3%) of essential oils of Nicotiana glauca, Ricinus comunis and Brassica carinata for the control of Meloidogyne spp was evaluated. A negative control (tween) and a positive control (Nakar nematicide 1.5 ml/L) were used. Samplings were made in farms planted with tomato in El Tambo, Cunchibamba, Quillan Loma and Izamba (Province of Tungurahua) and in Patain, Rumipamba, Salache, and Santa Ana (Province of Cotopaxi). The extraction of the nematodes was done by using the Baermann funnel. The morphometric data were subjected to a Principal Components Analysis (PCA) to determine the interpopulation variations. A wide variation of the morphometric variables was observed in the juveniles (J2) of the different populations of Meloidogyne sp. collected in Cotopaxi, mainly regarding the length of the body, width in the middle part, length of the stylet and b, while in the populations collected in Tungurahua the populations showed to be similar between them. The Principal Components Analysis explained up to 80.7% of the variation when considering the first three axes and indicated that the variables tail length, esophagus length and width in the middle part of the body had the highest weights to explain this variation. The mortality rate produced by the essential oils increased with the increase of the dose and time of exposure, with the best results when N. glauca oil was used at doses of 2 and 3%, followed by the oil of B. carinata. Based on the effectiveness of thes two essential oils, they could be incorporated into pest management programs against Meloidogyne population, however, field studies are suggested to validate the results under laboratory conditions. In this study molecular characterization was not made due to lack of equipments and time to standardization of the methodology.RESUMEN
Los nematodos agalladores de raíces del género Meloidogyne están ampliamente distribuidos a nivel mundial y son considerados los fitopatógenos más importantes debido a su impacto impacto en cultivos de importancia económica. En el presente estudio se evaluaron las variaciones morfométricas de poblaciones de Meloidogyne sp. colectadas en diferentes localidades de las provincias de Cotopaxi y Tungurahua. Adicionalmente se evaluó el efecto de diferentes dosis (1, 2 y 3%) de aceites esenciales de Nicotiana glauca, Ricinus comunis y Brassica carinata para el control de Meloidogyne spp. Se usó un testigo negativo (tween) y uno positivo (nematicida Nakar 1,5 ml/L). Los muestreos fueron hechos fincas sembradas con tomate riñón en El Tambo, Cunchibamba, Quillan Loma e Izamba (Provincia de Tungurahua) y en Patain, Rumipamba, Salache, y Santa Ana (Provincia de Cotopaxi). La extracción de los nematodos fue hecha mediante el uso del embudo de Baermann. Los datos mosrfométricos fueron sometidos a un análisis de Componentes Principales (ACP) para determinar las variaciones interpoblacionales. Se observó una amplia variación de las variables morfométricas en los juveniles (J2) de las diferentes poblaciones de Meloidogyne sp. Colectadas en Cotopaxi, principalmente en cuanto a la longitud del cuerpo, ancho en la parte media, longitud del estilete y b, mientras que en las poblaciones colectadas en Tungurahua las poblaciones mostraron más similitud entre ellas. El Análisis de Componentes Principales explico hasta un 80,7% de la variación al considerar los tres primeros ejes e indicó que las variables longitud de la cola, longitud del esófago y ancho en la parte media del cuerpo tuvieron los mayores pesos para explicar esta variación. La tasa de mortalidad producida por los diferentes aceites incrementó con el aumento de la dosis y tiempo de exposición, con los mejores resultados cuando se usó aceite de N. glauca a dosis de 2 y 3%, seguido del aceite de B. carinata. Basados en la efectividad de estos aceites esenciales, estos podrían ser incorporados en programas de manejo de poblaciones de Meloidogyne, sin embargo se sugiere realizar estudios de campo para validar los resultados en condiciones de laboratorio. En el presente estudio no se ha trabajado la caracterización molecular por motivo que no se tiene los equipos y limitación de tiempo para la estandarización de la metodología.Tesi
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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