Epidemiology of Citrus tristeza virus in nursery blocks of Citrus macrophylla and evaluation of control measures

Abstract

The control of Citrus tristeza virus (CTV), the causal agent of tristeza disease, is essential to guarantee a productive citrus industry. The specific features of a nursery block make the control of the natural spread of viruses transmitted by vectors more difficult. Thus, the knowledge of the epidemiology of CTV in nursery blocks is basic to the design control strategies of the disease. Two experimental nursery plots of alemow (Citrus macrophylla) were planted in open field in Moncada (Valencia, Spain) (with a high CTV prevalence, 85%), and in Alcanar (Tarragona, Spain) with 700 and 843 nursery plants, respectively. The plants were analysed by tissue print-ELISA using 3DF1 and 3CA5 CTVspecific monoclonal antibodies. The CTV prevalence estimated after one year of cultivation in both plots was of 24.37% and 3.91%, respectively. At the same time, a commercial nursery plot grown under plastic-net covers established in Alcanar with 1,200 plants was also analysed as above, being the CTV prevalence estimated of 0.00%. The aphid activity present in the nursery plots was monitored. Aphis spiraecola was the most abundant aphid species visiting the plants in the nursery plots grown in the open field, whereas the aphid activity registered in the plants grown under the plasticnet covers was practically zero. The percentage of individual aphids carrying CTV PCR-amplifiable targets detected by squash real-time RT-PCR in the open-field nursery plots was 17.5% in Moncada and 1.67% in Alcanar. No significant differences in the CTV prevalence between treated and non-treated plants with horticultural mineral oils were found in the area with the high CTV-inoculum pressure.Additional key words: alemow; horticultural mineral oil treatments; physical barriers; semi-persistent virus; squash real-time RT-PCR; tissue print-ELISA; vector intensity. Resumen Epidemiología del virus de la tristeza de los cítricos en bloques de vivero de Citrus macrophylla y evaluación de medidas de controlEl control del virus de la tristeza de los cítricos (Citrus tristeza virus, CTV), agente causal de la enfermedad de la tristeza, es esencial para garantizar una industria citrícola productiva. Las características específicas de los viveros hacen más difícil el control de los virus de vegetales transmitidos por insectos vectores. Así, el conocimiento de la epidemiología de CTV en bloques de plantas de vivero es básico para diseñar estrategias de control de la enfermedad. Dos parcelas experimentales de vivero cultivadas en campo abierto de Citrus macrophylla se establecieron en Moncada (Valencia, España) (con una alta prevalencia de CTV, 85%) y Alcanar (Tarragona, España) con 700 y 843 plantas de vivero, respectivamente. Las plantas se analizaron mediante Inmunoimpresión-ELISA usando los anticuerpos monoclonales específicos 3DF1 y 3CA5 de CTV. La prevalencia de CTV estimada en ambas parcelas después de un año de cultivo fue del 24,37% y del 3,91%, respectivamente. Al mismo tiempo, una parcela de vivero comercial cultivada bajo cubierta de plástico con...

Search for potential vectors of ‘Candidatus Liberibacter solanacearum’: population dynamics in host crops

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Spatial and temporal spread of Citrus tristeza virus and its aphid vectors in the North western area of Morocco

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Current Status of Citrus Tristeza Virus in Major Citrus Growing Areas of Sargodha, Pakistan

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