Efectos de extractos de algas Macrocystis Pyrifera combinados con pseudomonas Koreensis sobre el crecimiento y la respuesta estomática al estado hídrico en portainjertos "Colt" de cereco dulce
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Date
2026
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Universidad de Concepción
Abstract
El portainjerto Colt (Prunus avium × Prunus pseudocerasus) se utiliza ampliamente en los huertos de cerezos chilenos debido a su alta compatibilidad y vigor; sin embargo, su baja tolerancia a la sequía limita su rendimiento en entornos con escasez de agua. Los bioestimulantes derivados de extractos de algas marinas combinados con bacterias promotoras del crecimiento vegetal (PGPB) han demostrado efectos positivos en cultivos herbáceos, pero su impacto en especies leñosas sigue sin estar muy estudiado. Este estudio evaluó las respuestas fisiológicas y morfológicas de plantas jóvenes de Colt a la aplicación de extractos de Macrocystis pyrifera obtenidos por hidrólisis alcalina (A2) e hidrólisis mixta (alcalina + enzimática, A1), solos o combinados con Pseudomonas koreensis (AG-97), bajo
riego abundante (WET) y riego deficitario (DRY). En condiciones WET, el tratamiento A1B aumentó la conductancia estomática en un 90 % y redujo la temperatura de las hojas (~2 °C), mitigando el riesgo de hipoxia durante los periodos de alta humedad del sustrato. Estas mejoras se asociaron con una mayor eficiencia fotoquímica (Fv/Fm) en condiciones de baja radiación y alargamiento del tallo (+23 cm frente a 10 cm en el control). En condiciones DRY, A1B redujo la conductancia estomática en ~70 % con un potencial hídrico < –1,1 MPa, lo que limitó la deshidratación y redujo la defoliación a menos del 15 % en comparación con el 40 % en las plantas tratadas solo con tratamiento B. Los tratamientos A1 y A1B también mostraron una mayor asimilación de carbono (>41 %). Estos resultados confirman un efecto sinérgico entre los extractos de algas marinas y las PGPB, mejorando la resiliencia fisiológica y el crecimiento del portainjerto Colt en regímenes hídricos contrastados.
The Colt rootstock (Prunus avium × Prunus pseudocerasus) is widely used in Chilean cherry orchards due to its high compatibility and vigor; however, its low drought tolerance limits its performance in water-scarce environments. Biostimulants derived from seaweed extracts combined with plant growth-promoting bacteria (PGPB) have shown positive effects on herbaceous crops, but their impact on woody species remains largely unexplored. This study evaluated the physiological and morphological responses of young Colt plants to the application of Macrocystis pyrifera extracts obtained by alkaline hydrolysis (A2) and mixed hydrolysis (alkaline + enzymatic, A1), alone or combined with Pseudomonas koreensis (AG-97), under abundant irrigation (WET) and deficit irrigation (DRY). Under WET conditions, treatment A1B increased stomatal conductance by 90% and reduced leaf temperature (~2 °C), mitigating the risk of hypoxia during periods of high substrate moisture. These improvements were associated with greater photochemical efficiency (Fv/Fm) under low radiation conditions and stem elongation (+23 cm vs. 10 cm in the control). Under DRY conditions, A1B reduced stomatal conductance by ~70% with water potential < –1.1 MPa, limiting dehydration and reducing defoliation to less than 15% compared to 40% in plants treated with PGPB alone. Treatments A1 and A1B also showed higher carbon assimilation (>41%). These results confirm a synergistic effect between seaweed extracts and PGPB, improving the physiological resilience and growth of the Colt rootstock under contrasting water regimes.
The Colt rootstock (Prunus avium × Prunus pseudocerasus) is widely used in Chilean cherry orchards due to its high compatibility and vigor; however, its low drought tolerance limits its performance in water-scarce environments. Biostimulants derived from seaweed extracts combined with plant growth-promoting bacteria (PGPB) have shown positive effects on herbaceous crops, but their impact on woody species remains largely unexplored. This study evaluated the physiological and morphological responses of young Colt plants to the application of Macrocystis pyrifera extracts obtained by alkaline hydrolysis (A2) and mixed hydrolysis (alkaline + enzymatic, A1), alone or combined with Pseudomonas koreensis (AG-97), under abundant irrigation (WET) and deficit irrigation (DRY). Under WET conditions, treatment A1B increased stomatal conductance by 90% and reduced leaf temperature (~2 °C), mitigating the risk of hypoxia during periods of high substrate moisture. These improvements were associated with greater photochemical efficiency (Fv/Fm) under low radiation conditions and stem elongation (+23 cm vs. 10 cm in the control). Under DRY conditions, A1B reduced stomatal conductance by ~70% with water potential < –1.1 MPa, limiting dehydration and reducing defoliation to less than 15% compared to 40% in plants treated with PGPB alone. Treatments A1 and A1B also showed higher carbon assimilation (>41%). These results confirm a synergistic effect between seaweed extracts and PGPB, improving the physiological resilience and growth of the Colt rootstock under contrasting water regimes.
Description
Tesis presentada para optar al grado de Magíster en Ciencias Agronómicas