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Experiencias compartidas sobre detección de micotoxinas de Fusarium a las harinas de soja, trigo y otros cultivos
Get PDFFil: Peruzzo, Alejandra. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin
Resistencia genética a la Cancrosis del tallo de soja causada por Diaporthe phaseolorum var. caulivora: una estrategia innovadora y sustentable
Get PDFFil: Peruzzo, Alejandra. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin
Search and identification of resistance to soybean stem canker caused by Diaporthe phaseolorum var. caulivora
No full textLa agricultura moderna requiere estrategias que incrementen la productividad de manera sustentable y el compromiso de mejorar y preservar la calidad de vida urbana, rural y el ambiente. Estados Unidos, Brasil y Argentina son los principales productores mundiales de soja; siendo los responsables del 80% de la producción de grano entre 1996-2017. En Argentina y el mundo las enfermedades causan pérdidas del 10-15%, constituyendo un factor limitante para el rendimiento y calidad de granos, semillas y derivados. La cancrosis del tallo de soja (CTS) es causada por el hongo Diaporthe phaseolorum en sus dos variedades: var. meridionalis (Dpm) y var. caulivora (Dpc). En el germoplasma de soja se identificaron 4 genes de resistencia dominantes, independientes y de herencia simple para la CTS-Dpm, actualmente denominados Rdm1-4. Posteriormente, se identificó y localizó en el mapa genético de soja al gen Rdm5. Sin embargo, los genes Rdm identificados para CTS-Dpm, no eran efectivos frente a CTS-Dpc. En consecuencia y dado que en el germoplasma de soja aun no habían sido identificados los genes Rdc para CTS-Dpc, esta enfermedad representó un desafío relevante en las últimas dos décadas. En virtud de que ciertos estudios realizados previamente habían mostrado la existencia de genotipos de soja con resistencia a CTS-Dpc, se propuso identificar y definir la herencia de genes Rdc de resistencia a esta enfermedad a través de técnicas mendelianas clásicas combinadas con marcadores moleculares específicos. Durante el desarrollo de esta tesis se obtuvieron cruzamientos efectivos entre genotipos diferenciales resistentes y susceptibles a CTS-Dpc, y sus respectivas F1. En esta etapa se incorporó el uso de marcadores moleculares como técnica biotecnológica complementaria, permitiendo detectar polimorfismos entre progenitores diferenciales y validar molecularmente a los individuos heterocigotas F1. Esta validación de la dotación heterocigota de los individuos F1, resultante de la hibridación efectiva entre sus progenitores, permitió avanzar en la obtención segura de las poblaciones segregantes F2 y F3. Luego, mediante la inoculación de una cepa seleccionada de Dpc, se caracterizó la reacción fenotípica de resistencia/susceptibilidad frente a CTS-Dpc de los progenitores (Resistente y Susceptible), los individuos F1, los individuos F2 y las plantas de cada familia F2:3 derivadas de una misma planta F2 (Pruebas de Progenie). A través de las proporciones fenotípicas observadas en las Pruebas de Pprogenie y filial F3 se logró inferir las proporciones genotípicas esperadas de los individuos respectivos antecesores en la generación F2. Como resultado, se logró detectar la presencia de un gen mayor de herencia simple que confiere resistencia a la CTS, siendo identificado como Rdc1, constituyendo éste el primer reporte mundial sobre genes de resistencia (Rdc) a CTS-Dpc. Los resultados obtenidos dieron cumplimiento a los objetivos planteados y permitirán además introgresar este gen Rdc de resistencia a CTS-Dpc en el germoplasma elite de soja, agregando valor e interés en los actuales programas de mejoramiento. Así, el mejoramiento genético convencional combinado con el uso de las nuevas herramientas biotecnológicas, seguirá contribuyendo al desarrollo de una agricultura sustentable y la reducción de la contaminación química y biológica residual.Modern agriculture requires strategies that increase productivity in a sustainable manner and commitment to improve and preserve the quality of urban, rural and environmental life. In Argentina and the world, soybean diseases constitute a limiting factor of yield and quality of the grains, seeds and derivates, causing between 10 and 15% of losses. Soybean stem canker (SSC) is caused by two varieties (var.) of the fungus Diaporthe phaseolorum: var. meridionalis (Dpm) and var. caulivora (Dpc). In soybean germplasm resistance genes were identified for SSC-Dpm. However, soybean genotypes bearing Rdm genes were not effective against SSC-Dpc. Since soybean germplasm does not have Rdc genes identified for SSC-Dpc, this disease represents a relevant challenge. In this context, it was proposed to identify and define the inheritance of Rdc resistance genes to SSC-Dpc through classical mendelian techniques assisted by specific molecular markers. Effective crosses between resistant and susceptible genotypes to SSC-Dpc, plus their respective F1, were obtained. At this stage, the use of molecular markers was incorporated as a complementary biotechnological technique, allowing the detection of polymorphisms between differential progenitors and the molecular validation of F1 heterozygous individuals. The validation of the heterozygous endowment of F1 individuals, resulting from the effective hybridization of their parents, allowed to progress in the secure obtaining of segregating populations F2 and F3. Later, through the inoculation of a selected Dpc isolate, phenotypic reaction of the resistance/susceptibility to SSC-Dpc was evaluated in the progenitors (Resistance and Susceptible), F1 individuals, F2 individuals and plants of each F2:3 family derived from a single plant F2 (Progeny tests). Through the phenotypic proportions observed in Progeny tests and F3 individuals, genotypic proportions of F2 population were calculated. As a result, the detection of the presence of a major gene of simple inheritance that confers resistance to SSC, identified as Rdc1, was detected, constituting the first report about resistance genes to SSC-Dpc. The results allowed to achieve the proposed objectives and advance in the study of new Rdc genes for SSC-Dpc and resistance genes for others important diseases, adding value and interest in the current breeding programs. For this reason, conventional breeding combined with new biotechnology techniques offers a relevant and accessible tool that contributes to decrease chemicalbiological residual contamination and improves the development of a sustainable agriculture.Fil: Peruzzo, Alejandra María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentin
Mycotoxins in flours derived from wheat and soybean detected by the Elisa test
Get PDFEl objetivo de este trabajo fue evaluar la presencia de micotoxinas en las harinas derivadas de trigo y soja expuestos a la infección de Fusarium graminearum y detectadas por prueba de Elisa. La contaminación fue evaluada durante 2010 y 2012, en condiciones de invernadero, a través de inoculaciones artificiales y en lotes de producción en campo, expuestos a infecciones naturales. Se utilizaron 26 muestras de harinas derivadas de cariopsis de trigo y semillas de soja. La detección de micotoxinas deoxinivalenol y zearalenona se realizó por kit de Elisa. En harinas de trigo de diversos ambientes, se detectaron ambas micotoxinas ?deoxinivalenol y zearalenona?, mientras que en harinas de soja sólo se detectó zearalenona. Las concentraciones de esas micotoxinas observadas en las harinas no son admisibles para el consumo humano y animal. El kit de Elisa constituyó una herramienta biotecnológica efectiva para la detección de la contaminación predominante de zearalenona, producida por F. graminearum, en harinas de trigo y soja de diferentes ambientes (semicontrolados y naturales).The objective of this work was to evaluate the presence of mycotoxins in flours derived from wheat caryopses and soybean seed exposed to Fusarium graminearum infection and detected by the Elisa test. Contamination was evaluated during 2010 and 2012, in greenhouse conditions, by artificial inoculation, and on field-production batches exposed to natural infections. Twenty-six samples of flours derived from wheat caryopses and soybean seed were used. Detection of the mycotoxins deoxynivalenol and zearalenone was performed by an Elisa kit. In wheat flour of different environments both mycotoxins - deoxynivalenol and zearalenone - were detected, while in soybean flour only zearalenone was detected. Mycotoxins concentrations observed in these flours are inappropriate for human and animal consumption. Elisa kit constituted an effective biotechnological tool for the detection of prevailing contamination by zearalenone, caused by F. graminearum in wheat and soybean flours of different, semicontrolled and natural environments.Fil: Peruzzo, Alejandra María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Pioli, Rosanna Nora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentin
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
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