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Resumen
El trigo pan es uno de los cultivos de granos más importantes del mundo. Uno de los principales objetivos del mejoramiento genético a nivel mundial es el aumento del rendimiento en grano. El rendimiento es un carácter complejo, controlado por un elevado número de genes, con alta influencia ambiental e interacción genotipo por ambiente. Sumado a esto, el trigo es una especie alohexaploide de origen muy reciente (~8000 años) y por esto, las relaciones [ver mas...]
 
Bread wheat is one of the most important crops in the world. One of the main breeding goals in wheat is increasing grain yield. Yield is a complex trait, controlled by a high number of genes, with high environmental influence and genotype x environment interaction. Wheat is also an allohexaploid species of very recent origin (~8000 years), and for this reason, relationships among homeologous genes are complex. Therefore, the challenge of continuing to [ver mas...]
 
dc.contributor.advisorPontaroli, Ana Clara (directora)
dc.contributor.authorAlonso, Maria Pía
dc.date.accessioned2019-11-01T14:13:07Z
dc.date.available2019-11-01T14:13:07Z
dc.date.issued2018-03
dc.identifier.urihttp://hdl.handle.net/20.500.12123/6262
dc.identifier.urihttp://intrabalc.inta.gob.ar/dbtw-wpd/images/Alonso-M-P.pdf
dc.descriptionTesis para obtener el grado de Doctora en Ciencias Agrarias, presentada en la Facultad de Ciencias Agrarias de la Universidad Nacional de Mar del Plata, en marzo de 2018.es_AR
dc.description.abstractEl trigo pan es uno de los cultivos de granos más importantes del mundo. Uno de los principales objetivos del mejoramiento genético a nivel mundial es el aumento del rendimiento en grano. El rendimiento es un carácter complejo, controlado por un elevado número de genes, con alta influencia ambiental e interacción genotipo por ambiente. Sumado a esto, el trigo es una especie alohexaploide de origen muy reciente (~8000 años) y por esto, las relaciones entre genes homeólogos son complejas. Por lo tanto, el desafío de continuar mejorando sostenidamente el rendimiento requiere de la identificación de caracteres asociados al rendimiento de fácil medición y del trabajo interdisciplinario (ecofisiología, mejoramiento genético tradicional, genética molecular, bioinformática, estadística, entre otras). En este sentido, el objetivo del proyecto fue identificar regiones genómicas asociadas a la fertilidad de espiga (FE), un carácter de fácil medición a madurez, que está fuertemente asociado al número de granos por superficie, el principal determinante del rendimiento en trigo pan. Para esto, se utilizó una población de 146 líneas endocriadas recombinantes (RIL) derivadas del cruzamiento entre Baguette 10 (madre de alta FE) y Klein Chajá (padre de baja FE). Se realizaron tres ensayos a campo, durante los ciclos agrícolas 2013, 2014 y 2015, para determinar la FE, como así también el rendimiento y sus componentes para cada una de las líneas y sus parentales, además de otros caracteres de interés agronómico. Se analizó la correlación genética entre caracteres medidos y se estimaron los componentes de varianza de los mismos para calcular su heredabilidad en sentido estricto. Un grupo de 126 RIL fue genotipificado con un “chip” comercial (Axiom® 35K SNP Wheat Breeder‟s Array, Affimetrix). Se construyó un mapa de ligamiento con 857 marcadores SNP en 80 RIL, y se realizó un mapeo de QTL para los caracteres medidos a campo. La distribución de frecuencia de la FE para la población mostró una forma acampanada para los tres años de evaluación fenotípica, y segregación transgresiva hacia ambos lados de la distribución. La heredabilidad en sentido estricto del carácter fue de 0,84, con sólo un 11% de varianza total debida a la interacción genotipo x ambiente. La FE estuvo positivamente asociada al número de granos por unidad de superficie (r=0,48) mientras que estuvo negativamente asociada al peso de mil granos (r=-0,49). El rendimiento estuvo asociado al número de granos por superficie, mientras que no presentó asociación con el peso de mil granos. Se encontraron cuatro regiones genómicas (QTL) asociadas a la FE, en los cromosomas 1B, 2D, 5B y 7A. En total, estas regiones explicaron un 26% de la variación total en FE, no hubo interacción QTL por año y no hubo ninguna interacción entre QTL (p>0,05). Se desarrollaron marcadores homeólogo-específicos y alelo- específicos para cada uno de los marcadores contenidos en el intervalo de confianza de cada uno de los QTL. Cinco de los seis marcadores desarrollados para el QTL del cromosoma 2D fueron probados en un grupo de individuos de la población genotipificada, pero no fue posible amplificar el polimorfismo correspondiente de manera consistente. Debido al amplio intervalo de mapa de las regiones genómicas que mostraron asociación con la FE, no fue posible avanzar en la búsqueda de genes candidatos para el carácter. No obstante, los resultados del presente trabajo constituyen un avance significativo en el establecimiento de las bases genético- moleculares de la fertilidad de la espiga, escasamente conocidos hasta el momento. Bread wheat is one of the most important crops in the world. One of the main breeding goals in wheat is increasing grain yield. Yield is a complex trait, controlled by a high number of genes, with high environmental influence and genotype x environment interaction. Wheat is also an allohexaploid species of very recent origin (~8000 years), and for this reason, relationships among homeologous genes are complex. Therefore, the challenge of continuing to improve grain yield steadily requires the identification of easy-to-measure, yield-associated traits and an interdisciplinary focus that comprises ecophysiology, traditional breeding, molecular genetics, bioinformatics, and statistics, among others. In this sense, the objective of this study was to identify genomic regions associated with spike fertility (SF), a trait easily measured at maturity, which is strongly associated with the number of grains per unit area, the main determinant of yield in bread wheat. For this, a population of 146 recombinant inbred lines (RIL) derived from the cross between Baguette 10 (high SF) and Klein Chajá (low SF) was used. Three field trials were conducted during 2013, 2014 and 2015 growing seasons, to determine the SF, yield and its components, for each line and their parents, as well as other traits of agronomic interest. The genetic correlation between the measured traits was analyzed and their variance components were estimated in order to calculate their narrow-sense heritability. A group of 126 RIL was genotyped using a commercial "chip" (Axiom® 35K SNP Wheat Breeder's Array, Affimetrix). A linkage map was constructed with 857 SNP markers in 80 RIL and, for the measured traits, QTL mapping was performed. A bell-shaped distribution of SF was observed in the RIL population in all three years of phenotypic evaluation showing transgressive segregation towards both sides of the distribution. The narrow-sense heritability of SF was 0.84, with only 11% of total variance due to genotype x environment interaction. Spike fertility was positively associated with the number of grains per unit area (r = 0.48) while it was negatively associated with thousand grain weight (r = -0.49). Grain yield was associated with the number of grains per unit area, while it was not associated with thousand grain weight. Four genomic regions (QTL) associated with SF were found on chromosomes 1B, 2D, 5B and 7A. In total, these regions explained 26% of the total variation in SF, there was no QTL per year (environment) interaction and there was no interaction between QTL (p <0.05). Homeologous-specific and allele-specific markers were developed for each analyzed SNP included in the confidence interval of each QTL. Five of the six markers developed for the QTL of the 2D chromosome were tested in a group of individuals from the genotyped population, but it was not possible to amplify the corresponding polymorphism consistently. Due to the wide map range in the genomic regions associated with SF, it was not possible to advance in the search of candidate genes. Nevertheless, the results of this work constitute a significant advance in the establishment of the genetic-molecular bases of SF, scarcely known until now.spa
dc.description.abstractBread wheat is one of the most important crops in the world. One of the main breeding goals in wheat is increasing grain yield. Yield is a complex trait, controlled by a high number of genes, with high environmental influence and genotype x environment interaction. Wheat is also an allohexaploid species of very recent origin (~8000 years), and for this reason, relationships among homeologous genes are complex. Therefore, the challenge of continuing to improve grain yield steadily requires the identification of easy-to-measure, yield-associated traits and an interdisciplinary focus that comprises ecophysiology, traditional breeding, molecular genetics, bioinformatics, and statistics, among others. In this sense, the objective of this study was to identify genomic regions associated with spike fertility (SF), a trait easily measured at maturity, which is strongly associated with the number of grains per unit area, the main determinant of yield in bread wheat. For this, a population of 146 recombinant inbred lines (RIL) derived from the cross between Baguette 10 (high SF) and Klein Chajá (low SF) was used. Three field trials were conducted during 2013, 2014 and 2015 growing seasons, to determine the SF, yield and its components, for each line and their parents, as well as other traits of agronomic interest. The genetic correlation between the measured traits was analyzed and their variance components were estimated in order to calculate their narrow-sense heritability. A group of 126 RIL was genotyped using a commercial "chip" (Axiom® 35K SNP Wheat Breeder's Array, Affimetrix). A linkage map was constructed with 857 SNP markers in 80 RIL and, for the measured traits, QTL mapping was performed. A bell-shaped distribution of SF was observed in the RIL population in all three years of phenotypic evaluation showing transgressive segregation towards both sides of the distribution. The narrow-sense heritability of SF was 0.84, with only 11% of total variance due to genotype x environment interaction. Spike fertility was positively associated with the number of grains per unit area (r = 0.48) while it was negatively associated with thousand grain weight (r = -0.49). Grain yield was associated with the number of grains per unit area, while it was not associated with thousand grain weight. Four genomic regions (QTL) associated with SF were found on chromosomes 1B, 2D, 5B and 7A. In total, these regions explained 26% of the total variation in SF, there was no QTL per year (environment) interaction and there was no interaction between QTL (p <0.05). Homeologous-specific and allele-specific markers were developed for each analyzed SNP included in the confidence interval of each QTL. Five of the six markers developed for the QTL of the 2D chromosome were tested in a group of individuals from the genotyped population, but it was not possible to amplify the corresponding polymorphism consistently. Due to the wide map range in the genomic regions associated with SF, it was not possible to advance in the search of candidate genes. Nevertheless, the results of this work constitute a significant advance in the establishment of the genetic-molecular bases of SF, scarcely known until now.eng
dc.formatapplication/pdfes_AR
dc.language.isospaes_AR
dc.publisherFacultad de Ciencias Agrarias, Universidad Nacional de Mar del Plataes_AR
dc.rightsinfo:eu-repo/semantics/openAccesses_AR
dc.rights.urihttp://creativecommons.org/licenses/by-nc-sa/4.0/
dc.subjectTrigo Harineroes_AR
dc.subjectSoft Wheateng
dc.subjectEspigases_AR
dc.subjectSpikeseng
dc.subjectFertilidades_AR
dc.subjectFertilityeng
dc.subjectLoci de Rasgos Cuantitativoses_AR
dc.subjectQuantitative Trait Locieng
dc.subject.otherTrigo Panes_AR
dc.subject.otherQTL
dc.titleBases moleculares de la fertilidad de la espiga en trigo panes_AR
dc.typeinfo:ar-repo/semantics/tesis doctorales_AR
dc.typeinfo:eu-repo/semantics/doctoralThesises_AR
dc.typeinfo:eu-repo/semantics/publishedVersiones_AR
dc.rights.licenseCreative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.description.origenEEA Balcarcees_AR
dc.description.filFil: Alonso, María Pía. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.es_AR
dc.subtypetesis


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