ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
Not a member yet
2747 research outputs found
Sort by
Physiological Changes and Transcriptomic Analysis throughout On-Tree Fruit Ripening Process in Persimmon (Diospyros kaki L.)
Get PDFThe involvement of effectors and transcriptional regulators in persimmon fruit maturation has been mostly approached by the literature under postharvest conditions. In order to elucidate the participation of these genes in the on-tree fruit maturation development, we have collected samples from seven persimmon germplasm accessions at different developmental stages until physiological maturation. This study has focused on the expression analysis of 13 genes involved in ethylene biosynthesis and response pathways, as well as the evolution of important agronomical traits such as skin colour, weight, and firmness. Results revealed different gene expression patterns, with genes up- and down-regulated during fruit development progression. A principal component analysis was performed to correlate gene expression with agronomical traits. The decreasing expression of the ethylene biosynthetic genes DkACO1, DkACO2, and DkACS2, in concordance with other sensing (DkERS1) and transduction genes (DkERF18), provides a molecular mechanism for the previously described high production of ethylene in immature detached fruits. On the other side, DkERF8 and DkERF16 are postulated to induce fruit softening and skin colour change during natural persimmon fruit ripening via DkXTH9 and DkPSY activation, respectively. This study provides valuable information for a better understanding of the ethylene signalling pathway and its regulation during on-tree fruit ripening in persimmon
Competitive interactions in insect parasitoids: effects of microbial symbionts across tritrophic levels
Get PDFCompetition for hosts is a common ecological interaction in insect parasitoids. In the recent years, it has become increasingly evident that microorganisms can act as ‘hidden players’ in parasitoid ecology. In this review, we propose that parasitoid competition should take into consideration the microbial influence. In particular, we take a tritrophic perspective and discuss how parasitoid competition can be modulated by microorganisms associated with the parasitoids, their herbivore hosts, or the plants attacked by the herbivores. Although research is still in its infancy, recent studies have shown that microbial symbionts can modulate the contest outcome. The emerging pattern is that microorganisms not only affect the competitive traits of parasitoids but also the fighting arena (i.e. the herbivore host and its food plant), in which competition takes place. We have also identified important gaps in the literature that should be addressed in future studies to advance our understanding about parasitoid competition
A new and accurate qPCR protocol to detect plant pathogenic bacteria of the genus ‘Candidatus Liberibacter’ in plants and insects
Get PDFFour pathogenic bacterial species of the genus ‘Candidatus Liberibacter’, transmitted by psyllid vectors, have been associated with serious diseases affecting economically important crops of Rutaceae, Apiaceae and Solanaceae families. The most severe disease of citrus plants, huanglongbing (HLB), is associated with ‘Ca. Liberibacter asiaticus’ (CaLas), ‘Ca. Liberibacter americanus’ (CaLam) and ‘Ca. Liberibacter africanus’ (CaLaf), while ‘Ca. Liberibacter solanacearum’ (CaLsol) is associated with zebra chip disease in potatoes and vegetative disorders in apiaceous plants. Since these bacteria remain non-culturable and their symptoms are non-specific, their detection and identification are done by molecular methods, mainly based on PCR protocols. In this study, a new quantitative real-time PCR protocol based on TaqMan probe, which can also be performed in a conventional PCR version, has been developed to detect the four known phytopathogenic species of the genus Liberibacter. The new protocol has been validated according to European Plant Protection Organization (EPPO) guidelines and is able to detect CaLas, CaLam, CaLaf and CaLsol in both plants and vectors, not only using purified DNA but also using crude extracts of potato and citrus or psyllids. A comparative analysis with other previously described qPCR protocols revealed that this new one developed in this study is more specific and equally or more sensitive. Thus, other genus-specific qPCR protocols have important drawbacks regarding the lack of specificity, while with the new protocol there was no cross-reactions in 250 samples from 24 different plant and insect species from eight
different geographical origins. Therefore, it can be used as a rapid and time-saving screening test, as it
allows simultaneous detection of all plant pathogenic species of ‘Ca. Liberibacter’ in a one-step assay
Evaluación del uso de agua marina desalinizada con diferentes concentraciones de boro para el riego en cítricos. Resultados preliminares
Get PDFEn las principales zonas citrícolas, donde predomina el clima semiárido, la disponibilidad de agua para el riego representa el principal factor limitante de la producción y rentabilidad del cultivo. En este contexto, el agua marina desalada (AMD) se posiciona como un recurso hídrico estratégico que puede contribuir a la sostenibilidad de la agricultura de regadío. Sin embargo, desde el punto de vista de su uso para riego, el AMD, a pesar de su baja salinidad (EC25≈0.5 dS m-1), presenta diversos problemas agronómicos asociados a desequilibrios, ya que ciertos elementos presentan concentraciones muy reducidas mientras que elementos como el boro (B3+) se mantienen en concentraciones relativamente elevadas ([B3+]≈ 1,5 mg L-1–RD 3/2023) que podrían producir daños por toxicidad en cultivos sensibles como los cítricos. El objetivo principal del estudio fue la evaluación de los efectos fisiológicos y agronómicos a corto plazo del riego con AMD con diferente concentración de B3+ en una plantación joven de naranjo ‘Navelina N7’ (Citrus sinensis L. Osbeck) durante un ciclo de cultivo (2021-2022). Para el riego se han utilizado dos fuentes de agua: Agua convencional procedente de pozo (Pozo, [B3+] = 0,1 mg·L-1), apta para el riego de cítricos y AMD con 2 niveles de B3+ diferentes: AMD1 ([B+3] = 0,5 mg·L-1) y AMD2 ([B+3] = 1 mg·L-1). Los tres tratamientos de riego; Pozo, AMD1 y AMD2 fueron regados con el mismo volumen de agua (100% ETc). Se analizaron parámetros del estado hídrico de la planta, la acumulación de B3+ en el suelo y hojas y el desarrollo vegetativo. Los primeros resultados mostraron que el riego con AMD supuso un aumento de la concentración de B3+ en el suelo, principalmente en la zona radicular. Esta acumulación de boro en el suelo fue mayor en árboles regados con la concentración de B3+ más elevada (AMD2). A nivel de planta, el contenido de B3+ foliar solo aumentó en plantas del tratamiento AMD2. En términos fisiológicos, la baja CE del AMD (CE = 0,7 dS m-1) no generó alteraciones en el estado hídrico del cultivo, mostrando un desarrollo vegetativo similar a los árboles regados con agua de pozo (CE = 1,3 dS m-1). En base a estos resultados, el riego continuado con AMD no generó alteraciones fisiológicas significativas a corto plazo. Por lo tanto, los resultados obtenidos respaldan la viabilidad del riego con AMD en el corto plazo. Sin embargo, los resultados obtenidos en este ensayo son preliminares, y el estudio deberá extenderse durante un periodo más prolongado para evaluar los efectos de la utilización de AMD en cítricos a largo plazo
Efecto de la inclusión de dos tipos de orujo de aceituna en la dieta sobre el metaboloma fecal de los cerdos: resultados preliminares
Get PDFRecent advances in biological control of citrus pests and diseases
No full textCitrus cultivation is characterized by high species richness and an abundance of pest insects and associated natural enemies. Since the successful introduction of Novius (= Rodolia) cardinalis into California in the late 19th century, which resulted in the world’s first classical biological control (BC) program that targeted Icyerya purchasi, numerous classical BC programs have been initiated for the control of citrus pests, many of which have been very successful. The introduced and established new natural enemy species, together with the resident (both native and self-introduced), have enabled the development of conservation and augmentative BC programs in citrus. As a result, relatively few phytophagous species in citrus are considered key pests. However, this scenario has been disrupted by the spread of the lethal citrus disease, huanglongbing (HLB), caused by several bacteria of the genus Candidatus Liberibacter and vectored by psyllids, and by the higher arrival frequency of invasive pest species. Current management of HLB often requires broad-spectrum insecticide treatments to reduce vector densities to slow pathogen dissemination. Increased insecticide use in citrus disrupts BC and destabilizes Integrated Pest Management programs, which become more insecticide-intensive. The accelerating problem with invasive citrus pests is driven by increasing levels of international trade, tourism, and agriculture, as well as climate change. BC of these invasive pests in citrus is further complicated by increasing legal limitations imposed on the introduction of exotic natural enemies which further jeopardizes citrus farming in many citrus-producing regions. This special issue covers different aspects of BC programs against pests and diseases in several different citrus-growing regions. Work covered here also includes recent advances in BC postharvest citrus diseases and nematodes
Hydroxypropyl Methylcellulose and Gum Arabic Composite Edible Coatings Amended with Geraniol to Control Postharvest Brown Rot and Maintain Quality of Cold-Stored Plums
Get PDFIn this study, the effect of hydroxypropyl methylcellulose (HPMC) and gum Arabic (GA) edible coatings amended with 0.2% geraniol (GE) were evaluated for the control of brown rot, caused by Monilinia fructicola, on artificially inoculated plums (Prunus salicina Lindl., cv. Angeleno) stored for 5 weeks at 1°C. Brown rot is the most important pre- and postharvest fungal disease of stone fruits, causing severe economic losses worldwide. Geraniol is an important constituent of many essential oils that can be obtained as a byproduct from different industrial procedures, such as those of the juice industry. Fruit postharvest quality was also evaluated after 5 and 8 weeks of storage at 1°C, followed by 3 days at 7°C plus 5 days at 20°C, simulating packinghouse, transport, and retail shelf-life conditions, respectively. HPMC coatings containing 0.2% GE reduced the incidence and severity of brown rot by 37.5 and 64.8%, respectively, compared to uncoated fruit after 5 weeks of storage at 1°C. HPMC-coated plums, with and without GE, showed the highest level of firmness, the lowest change in external peel color parameters (L*, a*, b*, C*, hue), and the lowest flesh bleeding compared to uncoated control and GA-coated samples throughout the entire storage period, which correlated with a higher gas barrier of these coatings without negatively affecting sensory quality. Furthermore, the HPMC-0.2% GE coating provided the highest gloss to coated plums, showing the potential of this coating as a safe and environmentally friendly alternative to conventional fungicides and waxes for brown rot control and quality maintenance of cold-stored plums
Natural Infection of Pomegranate (Punica Granatum) by Apple Dimple Fruit Viroid
Get PDFThe analysis by high throughput sequencing (HTS) and RT-PCR of Spanish pomegranate fruits showing yellow rings revealed the presence of viroid isolates closely related to fig isolates of apple dimple fruit viroid (ADFVd). The analysis of pomegranate public RNASeq data (Sequence Reads Archives, SRAs) from Israel provided evidence for the presence of similar ADFVd isolates in pomegranate trees in this country. In addition, reads or contigs of plum viroid I (PVd-I) isolates were also identified in two of the analyzed SRA datasets from Israel, suggesting the presence of this second viroid in pomegranate. Full length ADFVd genomic sequences have been recovered, increasing knowledge on the diversity of this viroid and on the pomegranate virome in which only four viruses and one viroid had previously been reported
Optimización de la aplicación de fitosanitarios en cítricos (I)
Get PDFEn este artículo se repasan algunas de las contribuciones queel Centro de Agroingeniería del Instituto Valenciano de Investigaciones Agrarias ha realizado para la optimización de la aplicación de fitosanitarios en tratamientos mecanizados con el objetivo de alcanzar un control de plagas y enfermedades en cltricos sostenible económica y medioambientalmente. Se describen las aplicaciones y herramientas relacionadas con la optimización de la dosis de aplicación, dejando para una segunda parte, que se publicará en próximos números,el correcto funcionamiento y ajuste de las máquinas tradicionales y la utilización de nuevas tecnologías de aplicación precisa
Un nuevo enfoque sostenible de gestión de plagas y enfermedades a través de la inducción de defensas de las plantas
No full textLas plantas son capaces de activar defensas en respuesta al ataque de herbívoros. Estas defensas pueden ser directas o indirectas, y pueden aprovecharse para su integración en programas de gestión sostenible de plagas y enfermedades. En estudios realizados por el IVIA, se ha demostrado que la exposición de plantas de tomate, pimiento y cítricos a varios volátiles inducidos por herbivoría (HIPV’s) aumentan la sobreexpresión de genes defensivos en comparación con plantas no expuestas. De estos volátiles, se ha seleccionado el (Z)-3-hexenil propanoato [(Z)-3-HP] por su capacidad para activar diversas rutas defensivas en los tres cultivos. Además, se ha confirmado que la exposición a (Z)-3-HP aumenta la producción de compuestos derivados de ácidos grasos y la acumulación de compuestos de defensa específicos. Para su aplicación práctica, y en colaboración con el grupo del CEQA de la UPV, se diseñaron difusores poliméricos de liberación controlada que son capaces de emitir (Z)-3-HP a tasas constantes durante períodos prolongados y que ya han sido probados en condiciones de campo en los tres cultivos mencionados. Los resultados obtenidos sugieren que el uso de HIPV’s puede ser una estrategia prometedora para la gestión sostenible de plagas y enfermedades en agricultura