3.18 Tesis doctorado

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Eco-morphological effects of large wood in mountain basins, under different level of forest management
(2018) Ugalde Pascual, Fernando Javier; Mao, Luca; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
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
Multivariate standardized indices - application beyond drought detection for operational drought management in semi-arid regions in the Americas
(2018) Oertel, Melanie; Meza, Francisco Javier; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
Use of biotechnological tools as support to domestication and breeding of Argylia radiata (L.) D. Don.
(2019) Morales Tapia, Pablo Andrés; Montenegro Rizzardini, Gloria; 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.
Characterization of seed dormancy of Nolana (Solanaceae) in the coastal Atacama Desert of Chile.
(2019) Hepp, Josefina; Contreras E., Samuel; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
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
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
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
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
Amino acids as modulators of the production of hydrogen sulfide in problematic wine fermentations.
(2019) Paredes Martínez, María José Carolina; Bordeu Schwarze, Edmundo; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
All stages of winemaking can present problems, but alcoholic fermentation is, in particular, the stage with most complications. During wine fermentation some conditions can result in sluggish or stuck fermentations. The information provided by routine measurements has not been sufficient to detect and diagnose the state of the fermentation, and in case of paralization, rescue it on time. Hence, real-time monitoring of key variables, using advanced instrumentation, would anticipate problematic situations. Nitrogen is one of the most studied variables for sluggish or stuck fermentations. However, only a fraction of the available nitrogen is assimilated by the yeasts, constituted by ammonium ions and free α-amino acids. Nitrogen compounds have also been associated to be key factors in volatile compounds formation, including hydrogen sulfide (H2S). Sulfide release during winemaking is a longstanding and serious problem. H2S is a malodorous compound with a low sensory threshold. It’s produced as metabolic requirement of yeast for synthesizing sulphur compounds. Its formation is carried out by the sulfate reduction pathway starting from organic and inorganic sources, such as sulfites, cysteine, and glutathione. The role of amino acids and ammonium on H2S formation has shown a high variability. Individual yeast nitrogen requirements, as well as its assimilation capacity of nitrogen compounds, together with the time nitrogen is supplemented during fermentation, are oenological factors that influence sulfide formation. Furthermore, yeast variability in sulfide metabolic regulation has also a major impact on H2S formation. Genetic variability, in the form of differential allelic expression controlling sulfide reduction pathway or adjacent routes, has been found to be a decisive trait that affects yeast capacity to produce H2S. However, this information hasn’t been able to help predict and control sulfide formation through alcoholic fermentation. Considering the above, in this research nitrogen, specifically its organic sources, is studied, as regulator of H2S formation. For this, the evolution of amino acids profile during wine fermentation of Cabernet Sauvignon must was measured. Two problematic fermentations conditions were evaluated, high initial sugar concentration and low initial assimilable nitrogen content, besides the standard winery condition, with four commercial wine yeast. Samples were collected at 24 hours intervals until the maximum amount of H2S was produced. Amino acids were evaluated by HPLC (High Performance Liquid Chromatography), allowing their quantification. A colorimetric method was exclusively developed to accurately quantify H2S production. Depending on the initial condition of the fermentation some amino acid showed a characteristic evolution profile, distinctive to each yeast. Most importantly, a unique H2S release patron was established for each wine yeast in relation to the starting conditions of the must fermentation.
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
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
Efecto del fotoperiodo sobre la estacionalidad reproductiva en guanacos (Lama guanicoe) hembras
(2019) Correa Estrada, Lina María; Riveros Fernández, José Luis; 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
Brassinosteroids as a tool for color improvement in red table grapes (Vitis vinifera L.).
(2019) Vergara Valderrama, Alexis Esteban; Pérez Donoso, Alonso Gastón; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
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
Physiological process involved in the flowering habit of ‘Chilean white strawberry’ (F. chiloensis subsp. chiloensis f. chiloensis).
(2020) Grez, Javiera; Gambardella C., Marina; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
The Chilean white strawberry (F. chiloensis subsp. chiloensis f. chiloensis) is a native genotype that only emits one inflorescence per plant during the season, unlike its descendant, the cultivated red strawberry (F. x ananassa). To determine the main processes involved in this response, several studies of plant morphology, floral induction, dormancy and branching were carried out. The main results indicated that floral induction does not respond photoperiod pathway as in F. x ananassa, and it is favored at low temperatures (below 9ºC). For dormancy release, the chilean white strawberry requires between 900-1,000 chilling units. Finally, the branching increased in response to decapitation and not to the Prohexadione-calcium application, as observed in F. x ananassa. These results allow to conclude that the flowering habit of Chilean white strawberry is defined by the low floral induction and branching. The species would have vernalization requirements for floral induction, not fulfilled in a climate change context. On the other hand, the strong apical dominance proven could be related to the domestication process of this crop. This new knowledge will allow adjusting cultivation and plant propagation techniques to improve the fruit production and avoid the disappearance of this important crop in Chile.
Seed predation and its relationship with the recruitment of seedlings of woody species in central Chile
(2020) Correa-Solís Román, María José; Becerra Osses, Pablo Ignacio; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal
La depredación de semillas puede reducir la cantidad y diversidad de especies que quedan disponibles para germinar y de esta manera afectar la regeneración. Además, la frecuencia y abundancia de depredadores de semillas y plántulas normalmente es mayor en parches de vegetación con mayor biomasa leñosa. Por lo tanto, la depredación de semillas y plántulas puede ser también mayor en esos parches de vegetación. Examinamos estas hipótesis a través de experimentos en donde evaluamos el efecto de la exclusión de depredadores de semillas y de especies leñosas en distintos tipos de parche de vegetación de la región tipo mediterránea de Chile. Nuestros resultados mostraron que depredación de semillas ocurre principalmente bajo los parches de vegetación arbórea y en todas localidades estudiadas, indicando que es un fenómeno bastante generalizado en la zona central de Chile. A pesar de la existencia de depredación de semillas y probablemente también de plántulas, la herbivoría no sería suficientemente fuerte para ser determinante en los niveles de reclutamiento de plántulas. En relación con la aplicabilidad de los resultados, aparentemente no se requiere protección de herbívoros cuando se realizan siembras o si la restauración se basa en regeneración natural.
Estimation of carbon dioxide, latent heat and sensible heat fluxes through surface renewal analysis in vertically trellised vineyards.
(2020) Tosoni, Damián Esteban; Meza, Francisco Javier; Pontificia Universidad Católica de Chile. Facultad de Agronomía e Ingeniería Forestal

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