3.18 Tesis doctorado

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A framework to analyze institutional systems for managing and governing water resources
(2023) Blanco, Elisa; Donoso H., Guillermo; Pontificia Universidad Católica de Chile. Facultad de Agronomía y Sistemas Naturales
Garantizar el acceso al agua implica más que una cuestión de disponibilidad, sino también una cuestión de gestión y gobernanza. Si bien algunos sistemas hídricos han demostrado éxito en la gestión eficiente de sus escasos recursos, muchos enfrentan desafíos cuando se trata de organizar y coordinar la asignación y gestión sostenible de sus recursos. Para comprender los sistemas de recursos naturales, se han desarrollado los Principios de Diseño de Bienes Comunes, los Sistemas Socio-ecológicos (SES, por sus siglas en inglés) y el marco de Análisis y Desarrollo Institucional (Institutional Analysis and Development framework, IAD), todos ellos arraigados en teorías de acción colectiva. Estas teorías se han empleado para comprender las formas en que operan los sistemas institucionales complejos y los, a menudo, intrincados procesos de toma de decisiones que tienen lugar dentro de ellos. Al mismo tiempo, para establecer reglas y comprender los roles dentro de estos sistemas institucionales, se ha desarrollado la teoría del diseño de mecanismos. Estas teorías aún no se han adaptado completamente para incorporar las complejidades y la fragmentación inherentes a los marcos institucionales del agua. Por lo tanto, la presente tesis pretende contribuir al avance del conocimiento y la comprensión sobre la gestión de los sistemas socio-ecológicos hídricos. Aspira a comprender, desentrañar, analizar y aplicar estas teorías, hacia el análisis de los sistemas hídricos. Con ello, el objetivo es desarrollar un marco analítico que pueda estudiar y comprender mejor los sistemas socio-ecológicos del agua para mejorar sus instituciones y gobernanza. Al hacerlo, este trabajo busca ofrecer orientación a una audiencia amplia, incluidos usuarios del agua, investigadores, formuladores de políticas y autoridades responsables de diseñar políticas y proteger la sostenibilidad de los recursos hídricos.
Ascophyllum nodosum-derived biostimulants modulate plant development through the regulation of hormones signaling
(2023) Pozo Valdés, Josefa del; O'Brien, José; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
In agriculture, biostimulants derived from Ascophyllum nodosum extracts (ANE) have been widely used as growth stimulants and for protecting crops against biotic and abiotic stresses. Despite their widespread use, we have limited knowledge about how these biostimulants work and their role in influencing phytohormones throughout the plant. To shed light on this, we conducted a study using two commercial ANE biostimulants, Exelgrow (EG) and Exelmax (EM), which are produced through different methods. The main objective was to characterize and compare the effects of these biostimulants on the phenotype and hormonal signaling in Arabidopsis thaliana. Our findings reveal that EG and EM exhibit different biostimulant activity in Arabidopsis. Furthermore, EG promotes cytokinin (CK) signaling and suppresses auxin (AUX) signaling in the root meristem, while EM stimulates AUX and inhibits CK signaling. The transcriptomic analysis provided insights into their mechanism of action, revealing a priming effect against stress. EG interacts mainly with salicylic acid (SA) and jasmonate pathways, collectively regulating the plant's response to various biotic stresses. On the other hand, EM interacts with the brassinosteroids (BR) pathway, regulating ROS signals and defense against nematodes and pathogens. Finally, the transcriptomic analysis suggest that EM could be indirectly regulating AUX through the downregulation of BR signaling.
Characterization of the primocane flowering trait in the red raspberry (Rubus idaeus L.) and the effect of low temperature
(2018) Contreras Moya, Elida; Gambardella C., Marina; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Characterization of viral agents present in tomato crops in Arica and Parinacota Region of Northern Chile
(2019) Rojas Bertini, Claudia Andrea; Rosales V., Marlene; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Data assimilation for modeling biophysical variables in Central Chile vineyards
(2022) García Gutiérrez, Víctor Alfonso; Meza, Francisco Javier; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Given the importance of phenology and evapotranspiration in Mediterranean vineyards, this doctoral thesis aims to answer the question, “How much does a model based on data assimilation with Sentinel-2 improve the goodness of fit of methods that estimate vineyard phenology and evapotranspiration?”. Chapter 2, entitled “Modeling phenology combining Data Assimilation techniques and Bioclimatic Indices in a Cabernet Sauvignon vineyard in Central Chile,” has the objective of evaluating a phenology model based on data assimilation with a phenological weather model and Sentinel-2 land surface phenology. Additionally, Chapter 3, entitled “Evaluation of Penman-Monteith Model Based on Sentinel-2 Data for the Estimation of Actual Evapotranspiration in Vineyards”, evaluates the Penman-Monteith model for remote sensing data based on the Leuning approach and a novel approach that incorporates the Stewart stomatal conductance model, by comparing independent data from an eddy covariance system. Finally, Chapter 4 concludes with the key findings and limitations of the research, and consequently, future research is proposed.
Development of predictive and detection models for internal browning, watercore and bitter pit in apples using Vis-NIR spectrometry.
(2019) Mogollón Lancheros, Miguel René; Zoffoli, Juan Pablo; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Economic modelling of water storage, irrigation and crop choice under water scarcity
(2023) Strappa García de la Huerta, Valentina; Melo Contreras, Óscar; Pontificia Universidad Católica de Chile. Facultad de Agronomía y Sistemas Naturales
In the context of climate change's impact on water resources, this thesis investigates three adaptive strategies for water use in agriculture: - Changing the irrigation policy: Examining farmers' responses to water availability uncertainty, especially for permanent crops, the study employs a dynamic economic model considering intertemporal effects. The results emphasize the tradeoff between water dose and crop area under water restrictions, crucial for optimal irrigation decisions.- Water storage policies: Addressing the need for efficient water management, the research focus on dam operating rules. Integrating rational expectations, the study develops optimal storage policies based on expected future water resources. Findings underscore the importance of bounded capacity in mitigating the effects of decreased mean water inflows.- Changing the crop mix: Exploring water scarcity's impact on crop choice in low- to medium-income nations, the study proposes an economic model where water, not land, is the primary decision variable for farmers. The research employs a multinomial logistic structure to analyze water allocations for crop choices in Peru.This interdisciplinary research integrates dynamic economic modeling to provide insights into optimal irrigation, water storage, and crop choice strategies, contributing to understanding adaptive responses amid changing climatic conditions and resource pressures.
Effect of olive oil and hydrogenated vegetable oil supplementation on rumen bacterial composition in dairy cows
(2019) Cancino Padilla, Nathaly; Vargas Bello, Einar; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Effect of saline irrigation on the carotenoids biosynthesis and fruit development of Solanum lycopersicum cv. Micro Tom.
(2019) Leiva Ampuero, Andrés; Vega C., Andrea; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Salinity is an environmental factor that limits plants growth and crop productivity, affecting biochemical and physiological mechanisms, as well as morphology in diverse plants. Decreasing in the photosynthetic capacity triggers important changes in plant development. It has been described that saline stress induce lipids, proteins and nucleic acids oxidative damage. To survive to these negative conditions, plants synthesize antioxidant molecules and detoxifying enzymes, in order to protect plant tissues against propagation of oxidative and cytotoxics species. In this context, Lycopene and ß-carotene have been correlated with antioxidant activities in several fruits. In a plant with moderate tolerance to salinity, such as tomato, high levels of NaCl decrease fruit size, number of leaves and stomatal density, reduce crop yield and negatively affect the carotenoids concentration. Interestingly, tomato plants exposed to low salinity significantly modifies the photosynthetic capacity, enhances carotenoid fruit accumulation and could improve tomato taste by increasing sugar and organic acids content. In this work, the effect of saline irrigation on the carotenoids biosynthesis and fruit development of Solanum lycopersicum cv. Micro Tom was studied. The results showed that after 8 weeks of irrigation with a 80mM to 160mM NaCl solutions negatively modified photosynthetic capacity, in terms of net photosynthesis, stomatic conductivity, photochemical efficiency, electron transport rate and non photochemical quenching. Also, after 14 weeks of a 40 to 160 mM salinity treatments, tomato fruits showed an early coloration, increasing the solid soluble content in comparison with the control. However, a reduction in fruit caliber and fresh weight was observed from 80 mM NaCl onwards. Finally, salinity treatments differentially changed expression of carotenoid biosynthetic genes and increased accumulation of several carotenoids under 120 to 160mM. Altogether, these results suggest that long term salt irrigation correlates with earliness in tomato, a major breeding characteristic in crop plants.Salinity is an environmental factor that limits plants growth and crop productivity, affecting biochemical and physiological mechanisms, as well as morphology in diverse plants. Decreasing in the photosynthetic capacity triggers important changes in plant development. It has been described that saline stress induce lipids, proteins and nucleic acids oxidative damage. To survive to these negative conditions, plants synthesize antioxidant molecules and detoxifying enzymes, in order to protect plant tissues against propagation of oxidative and cytotoxics species. In this context, Lycopene and ß-carotene have been correlated with antioxidant activities in several fruits. In a plant with moderate tolerance to salinity, such as tomato, high levels of NaCl decrease fruit size, number of leaves and stomatal density, reduce crop yield and negatively affect the carotenoids concentration. Interestingly, tomato plants exposed to low salinity significantly modifies the photosynthetic capacity, enhances carotenoid fruit accumulation and could improve tomato taste by increasing sugar and organic acids content. In this work, the effect of saline irrigation on the carotenoids biosynthesis and fruit development of Solanum lycopersicum cv. Micro Tom was studied. The results showed that after 8 weeks of irrigation with a 80mM to 160mM NaCl solutions negatively modified photosynthetic capacity, in terms of net photosynthesis, stomatic conductivity, photochemical efficiency, electron transport rate and non photochemical quenching. Also, after 14 weeks of a 40 to 160 mM salinity treatments, tomato fruits showed an early coloration, increasing the solid soluble content in comparison with the control. However, a reduction in fruit caliber and fresh weight was observed from 80 mM NaCl onwards. Finally, salinity treatments differentially changed expression of carotenoid biosynthetic genes and increased accumulation of several carotenoids under 120 to 160mM. Altogether, these results suggest that long term salt irrigation correlates with earliness in tomato, a major breeding characteristic in crop plants.Salinity is an environmental factor that limits plants growth and crop productivity, affecting biochemical and physiological mechanisms, as well as morphology in diverse plants. Decreasing in the photosynthetic capacity triggers important changes in plant development. It has been described that saline stress induce lipids, proteins and nucleic acids oxidative damage. To survive to these negative conditions, plants synthesize antioxidant molecules and detoxifying enzymes, in order to protect plant tissues against propagation of oxidative and cytotoxics species. In this context, Lycopene and ß-carotene have been correlated with antioxidant activities in several fruits. In a plant with moderate tolerance to salinity, such as tomato, high levels of NaCl decrease fruit size, number of leaves and stomatal density, reduce crop yield and negatively affect the carotenoids concentration. Interestingly, tomato plants exposed to low salinity significantly modifies the photosynthetic capacity, enhances carotenoid fruit accumulation and could improve tomato taste by increasing sugar and organic acids content. In this work, the effect of saline irrigation on the carotenoids biosynthesis and fruit development of Solanum lycopersicum cv. Micro Tom was studied. The results showed that after 8 weeks of irrigation with a 80mM to 160mM NaCl solutions negatively modified photosynthetic capacity, in terms of net photosynthesis, stomatic conductivity, photochemical efficiency, electron transport rate and non photochemical quenching. Also, after 14 weeks of a 40 to 160 mM salinity treatments, tomato fruits showed an early coloration, increasing the solid soluble content in comparison with the control. However, a reduction in fruit caliber and fresh weight was observed from 80 mM NaCl onwards. Finally, salinity treatments differentially changed expression of carotenoid biosynthetic genes and increased accumulation of several carotenoids under 120 to 160mM. Altogether, these results suggest that long term salt irrigation correlates with earliness in tomato, a major breeding characteristic in crop plants.Salinity is an environmental factor that limits plants growth and crop productivity, affecting biochemical and physiological mechanisms, as well as morphology in diverse plants. Decreasing in the photosynthetic capacity triggers important changes in plant development. It has been described that saline stress induce lipids, proteins and nucleic acids oxidative damage. To survive to these negative conditions, plants synthesize antioxidant molecules and detoxifying enzymes, in order to protect plant tissues against propagation of oxidative and cytotoxics species. In this context, Lycopene and ß-carotene have been correlated with antioxidant activities in several fruits. In a plant with moderate tolerance to salinity, such as tomato, high levels of NaCl decrease fruit size, number of leaves and stomatal density, reduce crop yield and negatively affect the carotenoids concentration. Interestingly, tomato plants exposed to low salinity significantly modifies the photosynthetic capacity, enhances carotenoid fruit accumulation and could improve tomato taste by increasing sugar and organic acids content. In this work, the effect of saline irrigation on the carotenoids biosynthesis and fruit development of Solanum lycopersicum cv. Micro Tom was studied. The results showed that after 8 weeks of irrigation with a 80mM to 160mM NaCl solutions negatively modified photosynthetic capacity, in terms of net photosynthesis, stomatic conductivity, photochemical efficiency, electron transport rate and non photochemical quenching. Also, after 14 weeks of a 40 to 160 mM salinity treatments, tomato fruits showed an early coloration, increasing the solid soluble content in comparison with the control. However, a reduction in fruit caliber and fresh weight was observed from 80 mM NaCl onwards. Finally, salinity treatments differentially changed expression of carotenoid biosynthetic genes and increased accumulation of several carotenoids under 120 to 160mM. Altogether, these results suggest that long term salt irrigation correlates with earliness in tomato, a major breeding characteristic in crop plants.Salinity is an environmental factor that limits plants growth and crop productivity, affecting biochemical and physiological mechanisms, as well as morphology in diverse plants. Decreasing in the photosynthetic capacity triggers important changes in plant development. It has been described that saline stress induce lipids, proteins and nucleic acids oxidative damage. To survive to these negative conditions, plants synthesize antioxidant molecules and detoxifying enzymes, in order to protect plant tissues against propagation of oxidative and cytotoxics species. In this context, Lycopene and ß-carotene have been correlated with antioxidant activities in several fruits. In a plant with moderate tolerance to salinity, such as tomato, high levels of NaCl decrease fruit size, number of leaves and stomatal density, reduce crop yield and negatively affect the carotenoids concentration. Interestingly, tomato plants exposed to low salinity significantly modifies the photosynthetic capacity, enhances carotenoid fruit accumulation and could improve tomato taste by increasing sugar and organic acids content. In this work, the effect of saline irrigation on the carotenoids biosynthesis and fruit development of Solanum lycopersicum cv. Micro Tom was studied. The results showed that after 8 weeks of irrigation with a 80mM to 160mM NaCl solutions negatively modified photosynthetic capacity, in terms of net photosynthesis, stomatic conductivity, photochemical efficiency, electron transport rate and non photochemical quenching. Also, after 14 weeks of a 40 to 160 mM salinity treatments, tomato fruits showed an early coloration, increasing the solid soluble content in comparison with the control. However, a reduction in fruit caliber and fresh weight was observed from 80 mM NaCl onwards. Finally, salinity treatments differentially changed expression of carotenoid biosynthetic genes and increased accumulation of several carotenoids under 120 to 160mM. Altogether, these results suggest that long term salt irrigation correlates with earliness in tomato, a major breeding characteristic in crop plants.
Etiology and epidemiology of gray mold of kiwifruit in Chile.
(2019) Riquelme Toledo, Danae; Zoffoli, Juan Pablo; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Evaluation of growing and photosynthetic parameters in response to simple and mixed infections with GRSPaV in plants of Vitis vinifera L., "Cabernet Sauvignon" cultivar and study of new strategies of GRSPaV elimination
(2019) Tobar Urzúa, Mariola; Rosales V., Marlene; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Factors that predisposing to persea americana Mill. to iInfections of botryosphaeriaceae species in central zone of Chile
(2019) Valencia Díaz, Ana Luisa; Gil Montenegro, Pilar Macarena; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Genetic and transcriptomic studies of testa color of Chilean landraces of common bean (Phaseolus vulgaris L.)
(2023) Rodríguez Alvarez, Yohaily; Schwember Neira, Andrés R.; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
El color de la testa de la semilla es una característica influenciada por la expresión de genes responsables de la producción y acumulación de compuestos fenólicos. Este rasgo resulta relevante en la capacidad comercial del poroto común y la calidad nutricional de su semilla. En este proyecto de tesis doctoral, se realizó un estudio genético y transcriptómico del color de la testa y la respuesta a déficit de riego utilizando variedades chilenas de poroto común. Consideradas muy probablemente el reservorio más antiguo del pool andino de poroto común y un recurso genético crucial para fines evolutivos, de mejoramiento y alimentarios. Se realizó un análisis de los compuestos fenólicos asociados al color de la testa en tres etapas reproductivas diferentes del desarrollo fenológico del cultivo, bajo el efecto de tratamientos hídricos contrastantes. Se realizó un análisis RNAseq para identificar genes candidatos responsables de la producción y acumulación de compuestos fenólicos en la testa, y se cuantificó su expresión. Se encontró que durante los estados fenológicos R7 y R8 de la variedad 'Peumo', se acumula un mayor contenido de taninos condensados, incluyendo catequina y epicatequina, en la testa del poroto en comparación con la variedad 'Tórtola'. Se identificó cuatro genes candidatos (Phvul.007G206000, Phvul.002G079300, Phvul.010G090300 y Phvul.009G040700) implicados en la producción y acumulación de taninos condensados, en este tejido bajo riego deficitario. Se realizó un análisis combinado de datos metabólicos y transcriptómicos un gen candidato (Phvul.002G079300) con regulación a la baja del flujo metabólico para reducir la producción y el transporte de monómeros de proantocianidinas en 'Tórtola' en comparación con 'Peumo'. Por primera vez, se reportan hallazgos novedosos para futuros estudios moleculares y bioquímicos de la coloración de la testa del poroto chileno que son importantes para los productores de poroto, la industria alimentaria y los consumidores.
Implementation of a Decision Support Rule for fungicides application against Botrytis cinerea in organic vineyards in Chile
(2023) Herrera Défaz, Mario Andrés; Valdés Gómez, Héctor; Pontificia Universidad Católica de Chile. Facultad de Agronomía y Sistemas Naturales
Este trabajo se enfocó en el desarrollo e implementación de una regla de decisión para el manejo de Botrytis cinerea, un hongo patógeno que afecta a los viñedos. El objetivo principal de esta investigación fue proporcionar una herramienta práctica y efectiva para los productores de uva orgánica, permitiéndoles optimizar el uso de biofungicidas y reducir los riesgos asociados con la enfermedad. La investigación se enfocó en la necesidad de encontrar soluciones que sean compatibles con los principios de la agricultura orgánica, evitando el uso de productos químicos sintéticos. En este sentido, se evaluaron diferentes enfoques, incluyendo el uso de biofungicidas comerciales y una nueva molécula desarrollada a partir de quitosano y riboflavina. La metodología utilizada incluyó la recopilación de datos sobre la incidencia de Botrytis cinerea en viñedos orgánicos, así como pruebas de laboratorio para evaluar la eficacia de los diferentes tratamientos biofungicidas. Los resultados de la investigación demostraron la viabilidad y eficacia de la regla de decisión propuesta para el manejo de Botrytis cinerea en viñedos orgánicos usando indicadores clave en el desarrollo fenológico del cultivo. Esta regla de decisión se basa en un conjunto de criterios que tienen en cuenta factores como el estado fenológico de la vid, las condiciones climáticas locales (temperatura y humedad relativa). Con relación a los tratamientos evaluados, se encontró que tanto algunos de los biofungicidas comerciales, y la nueva molécula basada en quitosano y riboflavina mostraron resultados prometedores en la reducción de la incidencia del patógeno. Estos hallazgos sugieren que existe un potencial considerable para el desarrollo de alternativas sustentables y efectivas para el manejo de botritis en viñedos orgánicos.
Metagenomic approach to study viruses and virus-like pathogens in native potatoes from Chiloé Archipelago
(2019) Peña Reyes, Elizabeth Carolina; Rosales V., Marlene; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Modeling farmer production and food-loss decisions: a quality-based approach
(2023) Nunes Jansen, Sarah; Foster Bonnette, William; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Polyploidy induction in blueberries for the development of a new cultivar
(2024) Jarpa-Tauler, Gabriela; Arce Johnson, Jorge Patricio; Pontificia Universidad Católica de Chile. Facultad de Agronomía y Sistemas Naturales
La creciente competencia en el mercado internacional de arándanos que enfrenta Chile, junto con el cambio climático, exige la adopción de cultivares mejor adaptados que produzcan frutos de mayor calidad, firmeza y durabilidad en postcosecha. Esta tesis se centra en el mejoramiento genético de especies frutales mediante la poliploidización, con el objetivo de desarrollar nuevos cultivares de arándano highbush con ploidía aumentada. Los resultados indican que la aplicación de 1 mg/L de zeatina favorece la regeneración de brotes a partir de explantes de hojas y microtallos de los cultivares 'Biloxi', 'Legacy' y 'Duke' in vitro. Además, la combinación de 0,1% de colchicina y 1 mg/L de zeatina en medio sólido in vitro induce poliploidía en dichos explantes, logrando la producción exitosa de 10 octoploides y 8 mixoploides. La citometría de flujo se confirma como el método más confiable para identificar la poliploidía, resaltando las limitaciones de las características anatómicas para la detección preliminar. Los hallazgos respaldan la inducción de poliploidización como una técnica viable para generar variabilidad en arándanos. Sin embargo, es esencial evaluar estos mutantes en el futuro para asegurar los beneficios económicos potenciales derivados del incremento de ploidía.
Sediment transport dynamics in a glacierized Andean basin: lessons from the Estero Morales, Chile
(2022) Carrillo Muñoz, Ricardo; Mao, Luca; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Suspended and bedload transport dynamics on rivers draining glacierized basins depend on complex processes of runoff generation along with the degree of sediment connectivity and coupling at the basin scale. This thesis presents a recent dataset of sediment transport in the Estero Morales, a 27 km2 glacier-fed basin in Chile where suspended sediment concentration (SSC) and bedload (BL) fluxes have been continued monitored during two ablation seasons. The relationship between discharge and SSC depends on the origin of runoff, being transported in higher quantities during glacier melting, although the hysteresis index reveals that sediment sources are closer to the outlet during snowmelt. As for suspended sediment transport, bedload yield and availability depend on the origin of runoff. The relationship between discharge and BL reveals that early glacier melt period transport higher quantities of coarse sediments, and with higher efficiency, and the hysteresis suggests that sediments are provided by the proglacial area. Differences in volumes of transported sediments between the two studied ablation periods reveal differences in coupling mechanism on the sediment cascade, due to progressive changes of type and location of the main sources of runoff and sediments in this glacierized basin.
Tolerance strategies of Atriplex atacamensis and A. halimus in response to multiple abiotic stresses
(2019) Orrego Márquez, Fabiola Alejandra; Ginocchio Cea, Rosanna; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal

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