Análisis filogenético y sensibilidad a metalaxil de aislados de Phytophthora relacionados con el cultivo de almendro (Prunus dulcis Mill.)

Abstract

[ES] Desde la última década, el cultivo del almendro está experimentando importantes cambios, con un incremento continuo de la superficie de cultivo. Gran parte de las nuevas plantaciones se ha establecido bajo un régimen de regadío, cultivándose nuevas variedades con capacidad productiva alta que, junto con la recolección mecanizada, o las plantaciones denominadas ¿superintensivas¿, ha generado cuotas de producción mayores y posibilitado el cultivo de este frutal en zonas no tan propicias o tradicionales. Paralelamente a estos cambios, se constata un incremento en la incidencia y severidad de la podredumbre de cuello y raíz del almendro asociada a infecciones por Phytophthora spp. En este trabajo se propone un análisis filogenético de una colección de aislados de Phytophthora obtenidos en plantaciones de almendro con síntomas característicos de esta enfermedad, tales como decaimiento, gomosis en la parte baja del tronco, marchitez, defoliación, colapso y/o muerte. Para ello, se amplificarán la región ITS del ADN ribosómico y los genes cox I, β-tubulina y factor de elongación-1α. A su vez, puesto que las fenilamidas constituyen un grupo de fungicidas con riesgo alto de generación de resistencia, se estudia la sensibilidad de estos aislados de Phytophthora a diferentes concentraciones (0,1; 1; 5; 10; 100 ppm) de la materia activa metalaxil sobre el crecimiento miceliar a través del cálculo CE50.

[EN] Since the last decade, almond crop has undergone important changes, with a continuous increase in the cultivation area. A large part of the new plantations has been established under an irrigated regime, growing new varieties with a high productive capacity that, together with mechanized harvesting, or the so-called ¿super-intensive¿ plantations, has generated higher production quotes and made possible the cultivation of this fruit tree in areas not so favorable or traditional. Parallel to these changes, an increase in the incidence and severity of almond canker and root rot associated to infections by Phytophthora spp. has been observed. This work proposes a phylogenetic analysis of a collection of Phytophthora isolates obtained from almond plantations showing characteristic symptoms of the disease, such as decline, gummosis, wilt, defoliation and/or tree death. For this, the ITS region of the ribosomal DNA, and the cox1, β-tubulin, and elongation factor-1α genes will be amplified. In turn, since phenylamides constitute a group of fungicides with a high risk of generating resistance, the sensitivity of these Phytophthora isolates to different concentrations (0.1, 1; 5; 10; 100 ppm) of the fungicide metalaxyl on mycelial growth is studied through the EC50.

[CA] Since the last decade, almond crop has undergone important changes, with a continuous increase in the cultivation area. A large part of the new plantations has been established under an irrigated regime, growing new varieties with a high productive capacity that, together with mechanized harvesting, or the so-called “super-intensive” plantations, has generated higher production quotes and made possible the cultivation of this fruit tree in areas not so favourable or traditional. Parallel to these changes, an increase in the incidence and severity of almond canker and root rot associated to infections by Phytophthora spp. has been observed. This work proposes a phylogenetic analysis of a collection of Phytophthora isolates obtained from almond plantations showing characteristic symptoms of the disease, such as decline, gummosis, wilt, defoliation and/or tree death. For this, the ITS region of the ribosomal DNA, and the cox1, β-tubulin, and elongation factor-1α genes will be amplified. In turn, since phenylamides constitute a group of fungicides with a high risk of generating resistance, the sensitivity of these Phytophthora isolates to different concentrations (0.1, 1; 5; 10; 100 ppm) of the fungicide metalaxyl on mycelial growth is studied through the EC50.