1,720,970 research outputs found
Assessing Payne score accuracy through a bread wheat multi-genotype and multi-environment set from CIMMYT
No full textThe Payne score is a prevalent strategy for assessing wheat quality by considering the distinct contributions of specific high-molecular-weight glutenin subunits. Despite its extensive use, the limited germplasm used in its development (84 British cultivars from the early 1980s) may limit its accuracy when is applied to other type of germplasm. Here we tested the Payne score accuracy and related scales using an extensive dataset. The precision of the scale is higher for Glu-A1 and Glu-D1 loci, particularly when predicting dough strength, and loaf volume. However, for dough extensibility, the accuracy decreased. For Glu-B1 it could discriminate differences to some extent, but higher scores did not always correspond to higher quality values, and vice versa. When the total Payne score was evaluated, the most pronounced degree of differentiation between scale values was observed for gluten strength related traits. When analyzing the total Payne score for various haplotypes, higher values for gluten strength, and loaf volume generally corresponded to higher Payne scores; however, some samples with low values were ranked with the highest scores and vice versa. Our findings suggest that there is a probability of selecting cultivars with high Payne scores that do not match the desired quality.Instituto de Recursos BiológicosFil: Tabbita, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina; Universidad de Córdoba. Escuela Técnica Superior de Ingeniería Agronómica y de Montes. Departamento de Genética; EspañaFil: Ibba, María Itria. International Maize and Wheat Improvement Center (CIMMYT); MéxicoFil: Andrade, Francisco. Universidad de Córdoba. Escuela Técnica Superior de Ingeniería Agronómica y de Montes. Departamento de Genética; EspañaFil: Crossa, José. International Maize and Wheat Improvement Center (CIMMYT); MéxicoFil: Guzman, Carlos. Universidad de Córdoba. Escuela Técnica Superior de Ingeniería Agronómica y de Montes. Departamento de Genética; Españ
Participación de la familia génica GPC sobre la concentración de proteínas y nutrientes en el grano y su relación con la senescencia foliar en plantas de trigo
Get PDFLa removilización de nutrientes al grano y la senescencia son procesos extremadamente interconectados en trigo que determinan la calidad nutricional y panadera. Mientras que el nitrógeno (N) afecta la concentración de proteínas en grano (CPG), en donde alta CPG generan productos panificables con una calidad superior, los micronutrientes como el hierro (Fe) y el Zinc (Zn) afectan la calidad nutricional. Por lo tanto, el mejoramiento de la calidad en trigo requiere un profundo entendimiento de las redes génicas que regulan y controlan la senescencia y la removilización de nutrientes al grano. El gen GPC-B1, proveniente del trigo silvestre Triticum turgidum var. diccocoides, pertenece a la familia de factores de transcripción NAC y es la primer fuente de variación para CPG y micronutrientes identificada en trigo. Los objetivos de esta tesis fueron: estudiar el efecto de la introgresión de GPC-B1 sobre la CPG, concentración de micro y macronutrientes y diferentes parámetros agronómicos en germoplasma argentino; profundizar, mediante análisis transcriptómicos y el uso de plantas mutantes para los genes GPC el entendimiento de la regulación génica que ocurre durante la senescencia y finalmente identificar nuevos genes de transporte de N, Fe y Zn al grano mediante genómica comparativa con arroz. Cuando GPC-B1 se introdujo en germoplasma de origen argentino la CPG se incrementó entre 3 a 8,11 g kg-1 a través de diferentes cultivares y ambientes. A pesar del efecto negativo del gen sobre el tamaño de granos y una aceleración en la senescencia, no se observaron diferencias significativas en rendimiento. El incremento en la CPG se explicó por una mayor proteólisis y eficiencia en el transporte de aminoácidos al grano. Cuando se analizó la concentración de nutrientes, se observaron incrementos consistentes en Fe. La combinación de análisis transcriptómicos y plantas mutantes permitió identificar 3888 genes diferencialmente expresados durante la senescencia y 340 genes modulados por la familia GPC. A su vez, se han identificado 21 genes relacionados con el transporte de N al grano y se han caracterizado nueve familias génicas relacionadas con el transporte de Fe y Zn al grano que pueden utilizarse en programas de mejoramiento para incrementar la calidad nutricional en trigo
Estudio de la variabilidad intraespecífica en la acumulación de nutrientes en los granos de trigos argentinos con perspectivas para su biofortificación.
Get PDFTesis de IngenieríaA nivel mundial, el trigo (Triticum aestivum) es considerado uno de los cereales más importantes, debido principalmente a que es una fuente de nutrientes y proteínas esenciales para la nutrición. Aunque la productividad de la especie mejoró a lo largo del tiempo, la concentración de minerales importantes para la nutrición humana, como Zn, Fe, Mn, Cu, K, P, Ca, y Mg, en los granos disminuyó. En esta tesis, mediante el análisis del ionoma, se estudió la variabilidad en la acumulación de nutrientes minerales en una población de mapeo por asociación conformada por 102 líneas de trigos argentinos debidamente genotipadas. De forma preliminar, i) se fenotipó la concentración de 8 nutrientes esenciales y elementos potencialmente tóxicos (Sr y Al) en granos. ii) A partir de los datos genotípicos se realizó un estudio de asociación de genoma completo (GWAS) mediante el software GAPIT. Se observó una gran variabilidad y correlación para la acumulación de Al y Fe. Se observaron correlaciones positivas entre los pares Sr-Ca, Zn-Fe, y K-P. Se observó una correlación negativa entre las concentraciones de elementos y el peso de mil granos. Como resultado del estudio de mapeo por asociación se identificaron regiones genómicas asociadas a la acumulación de Fe y K. Mediante un estudio de tales regiones genómicas, se identificaron genes potencialmente candidatos.Worldwide, wheat (Triticum aestivum) is considered one of the most important cereals, mainly because it is a source of nutrients and proteins essential for nutrition. Although the productivity of the species improved over time, the concentration of minerals important for human nutrition, such as Zn, Fe, Mn, Cu, K, P, Ca, and Mg, in the grains decreased. In this thesis, through ionome analysis, the variability in the accumulation of mineral nutrients was studied in an association mapping population made up of 102 properly genotyped lines of Argentine wheat. Preliminarily, i) the concentration of 8 essential nutrients and potentially toxic elements (Sr and Al) in grains was phenotyped. ii) Using the genotypic data, a genome-wide association study (GWAS) was performed using the GAPIT software. A great variability and correlation was observed for the accumulation of Al and Fe. Positive correlations were observed between the Sr-Ca, Zn-Fe, and K-P pairs. A negative correlation was observed between the concentrations of elements and the weight of a thousand grains. As a result of the association mapping study, genomic regions associated with the accumulation of Fe and K were identified. Through a study of such genomic regions, potentially candidate genes were identified.Fil: Rivero, Alexander Gabriel. Universidad Nacional de San Martín. Escuela de Bio y Nanotecnologías. Instituto Tecnológico Chascomús (INTECH, CONICET-UNSAM); Buenos Aires, Argentina
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
Grain mineral composition of Argentinean-adapted wheat cultivars: a case study
No full textAbstract. Improvement of the nutritional quality of wheat (Triticum aestivum L.) has been quite challenging, due, in part, to the limited variation found in modern cultivars and the strong effect exerted by the environment, which hinder the selection process. The aim of this study was to characterise the mineral profile of grains of 35 Argentinean-adapted, mostly spring wheat cultivars in two successive years. Concentrations of most mineral nutrients in grains spanned approximately a two-fold range. Our study revealed a strong effect of the environment, but also that some key differences among genotypes are maintained over years. Correlation and principal component analyses showed the existence of a strong and stable association of variables determining the global elemental profile in grains of the wheat lines under analysis. In this regard, some cultivars displayed, over successive years, opposite global patterns of elemental composition, suggesting the existence of a genotype dependent ionome signature. Important negative correlations were found for the concentration of most, but not all, nutrients with yield, thus indicating a potential compromise among beneficial traits. The genotypic variation characterised in the present study has potential to be used in breeding programs aimed at improving wheat grain quality.Fil: D'Amico, Iván. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Silva, Mauro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Moriconi, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Santa-María, Guillermo E. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Bainotti, Carlos Tomas. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Tabbita, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Genética; Argentin
Functional characterization of GPC-1 genes in hexaploid wheat
Get PDFIn wheat, monocarpic senescence is a tightly regulated process during which nitrogen (N) and micronutrients stored pre-anthesis are remobilized from vegetative tissues to the developing grains. Recently, a close connection between senescence and remobilization was shown through the map-based cloning of the GPC (grain protein content) gene in wheat. GPC-B1 encodes a NAC transcription factor associated with earlier senescence and increased grain protein, iron and zinc content, and is deleted or non-functional in most commercial wheat varieties. In the current research, we identified 'loss of function' ethyl methanesulfonate mutants for the two GPC-B1 homoeologous genes; GPC-A1 and GPC-D1, in a hexaploid wheat mutant population. The single gpc-a1 and gpc-d1 mutants, the double gpc-1 mutant and control lines were grown under field conditions at four locations and were characterized for senescence, GPC, micronutrients and yield parameters. Our results show a significant delay in senescence in both the gpc-a1 and gpc-d1 single mutants and an even stronger effect in the gpc-1 double mutant in all the environments tested in this study. The accumulation of total N in the developing grains showed a similar increase in the control and gpc-1 plants until 25 days after anthesis (DAA) but at 41 and 60 DAA the control plants had higher grain N content than the gpc-1 mutants. At maturity, GPC in all mutants was significantly lower than in control plants while grain weight was unaffected. These results demonstrate that the GPC-A1 and GPC-D1 genes have a redundant function and play a major role in the regulation of monocarpic senescence and nutrient remobilization in wheat.Fil: Avni, Raz. Tel Aviv University; IsraelFil: Zhao, Rongrong. China Agricultural University; República de China. University of California at Davis; Estados UnidosFil: Pearce, Stephen. University of California at Davis; Estados UnidosFil: Jun, Yan. University of Haifa; IsraelFil: Uauy, Cristobal. University of California at Davis; Estados UnidosFil: Tabbita, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of California at Davis; Estados UnidosFil: Fahima, Tzion. University of Haifa; IsraelFil: Slade, Ann. Arcadia Biosciences Inc.; Estados UnidosFil: Dubcovsky, Jorge. University of California at Davis; Estados UnidosFil: Distelfeld, Assaf. Tel Aviv University; Israe
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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