Browsing by Author "Jarpa-Tauler, Gabriela"

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    Autopolyploidization and in vitro regeneration of three highbush blueberry (Vaccinium corymbosum L.) cultivars from leaves and microstems
    (SPRINGER, 2024) Jarpa-Tauler, Gabriela; Martinez-Barradas, Vera; Romero-Romero, Jesus Lucina; Arce-Johnson, Patricio
    Blueberries are a fruit with an increasing global demand due to their phytochemical and bioactive compounds content. They are promoted worldwide because of their health benefits. For optimal growth and productivity, blueberry crops need acidic soil pH, specific chilling hours, and an adequate atmospheric temperature. This delicate production equilibrium is under severe threat from climate change, potentially leading to reduced yields and increased cultivation costs unless new cultivars are developed for each edafoclimatic zone. Therefore, considering varietal replacements with more productive cultivars offering higher quality and better adaptability to local conditions is imperative. In this study, we employ polyploidization and in vitro tissue culture to promote variability and lay the foundation for new cultivar development. We report the successful induction of octoploids in three blueberry cultivars, namely 'Biloxi', 'Legacy', and 'Duke', through whole-genome duplication. Leaves and microstem explants were exposed to 0.1% colchicine for 24 and 48 hours in in vitro culture. After analyzing the polyploid level of 160 regenerated shoots using DNA flow cytometry, we obtained a total of 18 mutants, consisting of 8 mixoploids and 10 octoploids. The number of chloroplasts in the stomata was analyzed by fluorescence microscopy, revealing the duplication of these organelles in the induced octoploid plants. To our knowledge, this represents the first successful induction of octoploids in three blueberry cultivars -'Biloxi,' 'Legacy,' and 'Duke'- achieved by exposing leaves and microstem explants to colchicine in in vitro culture. This technique holds promise as a valuable tool for the development of improved blueberry cultivars.
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    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.