ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
Not a member yet
2747 research outputs found
Sort by
Coping With Water Shortage: An Update on the Role of K+, Cl-, and Water Membrane Transport Mechanisms on Drought Resistance
Get PDFDrought is now recognized as the abiotic stress that causes most problems in agriculture, mainly due to the strong water demand from intensive culture and the effects of climate change, especially in arid/semi-arid areas. When plants suffer from water deficit (WD), a plethora of negative physiological alterations such as cell turgor loss, reduction of CO2 net assimilation rate, oxidative stress damage, and nutritional imbalances, among others, can lead to a decrease in the yield production and loss of commercial quality. Nutritional imbalances in plants grown under drought stress occur by decreasing water uptake and leaf transpiration, combined by alteration of nutrient uptake and long-distance transport processes. Plants try to counteract these effects by activating drought resistance mechanisms. Correct accumulation of salts and water constitutes an important portion of these mechanisms, in particular of those related to the cell osmotic adjustment and function of stomata. In recent years, molecular insights into the regulation of K+, Cl-, and water transport under drought have been gained. Therefore, this article brings an update on this topic. Moreover, agronomical practices that ameliorate drought symptoms of crops by improving nutrient homeostasis will also be presented
Virus Detection by High-Throughput Sequencing of Small RNAs: Large-Scale Performance Testing of Sequence Analysis Strategies
Get PDFRecent developments in high-throughput sequencing (HTS), also called next-generation sequencing (NGS), technologies and bioinformatics have drastically changed research on viral pathogens and spurred growing interest in the field of virus diagnostics. However, the reliability of HTS-based virus detection protocols must be evaluated before adopting them for diagnostics. Many different bioinformatics algorithms aimed at detecting viruses in HTS data have been reported but little attention has been paid thus far to their sensitivity and reliability for diagnostic purposes. Therefore, we compared the ability of 21 plant virology laboratories, each employing a different bioinformatics pipeline, to detect 12 plant viruses through a double-blind large-scale performance test using 10 datasets of 21- to 24-nucleotide small RNA (sRNA) sequences from three different infected plants. The sensitivity of virus detection ranged between 35 and 100% among participants, with a marked negative effect when sequence depth decreased. The false-positive detection rate was very low and mainly related to the identification of host genome-integrated viral sequences or misinterpretation of the results. Reproducibility was high(91.6%). This work revealed the key influence of bioinformatics strategies for the sensitive detection of viruses in HTS sRNA datasets and, more specifically (i) the difficulty in detecting viral agents when they are novel or their sRNA abundance is low, (ii) the influence of key parameters at both assembly and annotation steps, (iii) the importance of completeness of reference sequence databases, and (iv) the significant level of scientific expertise needed when interpreting pipeline results. Overall, this work underlines key parameters and proposes recommendations for reliable sRNA-based detection of known and unknown viruses
Unravelling the effects of berry size on 'tempranillo' grapes under different field practices
Get PDFSmall berries are considered to produce the best red wines as berry size determines the skin to pulp ratio and may affect wine composition. However, contrasting results have been reported about this postulate. In this context, the aim of this work was to assess the influence of berry size on grape compositional attributes in 'Tempranillo' grapevines under different irrigation, crop load and defoliation regimes. Grapes were collected from different experiments performed during three years in a 'Tempranillo' vineyard (Valencia, Spain). Grape size distribution was assessed and several traits were measured for each size category: number of seeds, seed and skin weight, total soluble solids, titratable acidity, pH, total phenolic index and anthocyanin concentration. Berry size exerted a significant effect on grape composition; smaller berries having higher sugars and anthocyanins concentrations. However, irrigation, crop load and defoliation also affected these compositional traits, producing greater berries with similar traits than those smaller, but coming from rain-fed and not defoliated treatments. Depending on the field practices applied, grape compositional attributes can be modulated for a given berry size. Therefore, wineries can use berry size classification for selecting those from a given size for making different wine styles
Caracterización microbiológica de lodos y suelos. Establecimiento de indicadores sobre la fermentabilidad de los lodos
No full textLa aplicación de lodos de EDAR en agricultura como fuente de nutrientes, es considerada la mejor alternativa de valorización para dichos residuos, dado su alto contenido en materia orgánica y otros nutrientes esenciales para los cultivos. Sin embargo, la existencia de una legislación nacional algo desfasada que únicamente clasifica los lodos como aptos para su valorización agricultura en función de la presencia de metales pesados, ha traído como consecuencia la utilización de lodos con una baja estabilidad, con los problemas que esto conlleva, tales como, generación de olores, proliferación de insectos, problemas sobre cultivos y suelos, etc.
A su vez, dicha problemática ha provocado el desarrollado de legislaciones a nivel autonómico y local con criterios de aplicación diversos, que en ocasiones impiden la valorización agronómica de los lodos; en muchos casos sin una base técnica que los ampare.
Las actuales preocupaciones en materia de seguridad sanitaria y medioambiental, hacen necesario conocer metodologías, valores de referencia del grado fermentabilidad de los lodos y la caracterización microbiológica de los mismos; con el fin hacer viable a largo plazo dicha valorización.
Para ello, se realizó el estudio de la fermentabilidad y caracterización microbiológica de los lodos producidos en diez instalaciones de la Comunidad Valenciana, con los cuatro tratamientos más representativos de lodos existentes, siendo estos, estabilización aerobia mediante aireación prolongada, digestión anaerobia, secado térmico y compostaje, realizándose nueve muestreos a lo largo de un año.
Los criterios establecidos a la hora de definir los indicadores de fermentabilidad a estudiar, fueron que éstos resultaran fiables, sencillos y de bajo coste económico, por ello, los indicadores establecidos para el estudio de la fermentabilidad fueron contenido de materia orgánica calcinable (MOC), olor (O), contenido de carbono hidrosoluble (CH), demanda química de oxigeno (DQO), actividad respirométrica acumulada en 4 días (AT4) y demanda bioquímica de oxígeno a los cinco días (DBO5).
También se estudiaron 11 suelos de parcelas de diferentes zonas edafoclimaticas que habían sido enmendadas con lodo procedentes de un único tratamiento y parcelas próximas no aplicadas catalogadas como parcelas control.
Respecto a la caracterización microbiológica tanto de lodos como de suelos, los microorganismos patógenos estudiados fueron salmonella spp., huevos de helmintos, coliformes fecales, escherichia coli y clostridium perfringens.
De los métodos de fermentabilidad planteados, el Carbono Hidrosoluble, la Demanda Química de Oxigeno (DQO) y la Demanda Bioquímica de Oxigeno (DBO5), resultaron los más prometedores, existiendo diferencias significativas en función del tratamiento sufrido por los lodos, catalogando el compostaje como el tratamiento con mayor estabilización, frente a la estabilización aerobia mediante aireación prolongada como la menos estabilizante. La posible influencia de la humedad sobre estos indicadores merece un estudio ampliado.
Respecto a la caracterización microbiológica, el compostaje resulto único tratamiento que garantiza la higienización de los lodos, observándose que ni el tratamiento de estabilización aerobia (aireación prolongada), ni el de digestión anaerobia, consiguen una reducción de patógenos. Los resultados de la caracterización microbiológica de suelos no pudieron afirmar que exista una correlación clara entre la aplicación de lodos y la presencia de microorganismos patógenos los suelos receptores
Assessing the environmental sustainability of irrigation with oil and gas produced water in drylands
Get PDFProduced water (PW) is the largest by-product of the oil and gas industry. Its management is both economically and environmentally costly. PW reuse for irrigation offers an alternative to current disposal practices while providing water to irrigators in drylands. The aim of this investigation was to evaluate the environmental effects of irrigation with PW. The SALTIRSOIL_M model was used to simulate the irrigation of sugar beet with 15 PWs of a wide range of qualities in four climates of different aridity and on four contrasting soil types. The impacts on soil salinity, sodicity and pH as well as on crop yield and drainage water salinity were estimated. Well-drained soils with low water content at field capacity (Arenosol) are less sensitive to salinisation while a relatively high gypsum content (Gypsisol) makes the soil less vulnerable to both sodification and salinisation. On the contrary, clayey soils with higher water content at field capacity and lower gypsum content must be avoided as the soil structural stability as well as a tolerable soil electrical conductivity for the crop cannot be maintained on the long-term. Soil pH was not found to be sensitive to PW quality. Drainage water quality was found to be closely linked to PW quality although it is also influenced by the soil type. The impact of drainage water on the aquifer must be considered and reuse or disposal implemented accordingly for achieving sustainable irrigation. Finally, increasing aridity intensifies soil and drainage water salinity and sodicity. This investigation highlights the importance of adapting the existing irrigation water quality guidelines through the use of models to include relevant parameters related to soil type and aridity. Indeed, it will support the petroleum industry and irrigators, to estimate the risks due to watering crops with PW and will encourage its sustainable reuse in water-scarce areas
Draft Genome Resources of Two Strains ("ESVL" and "IVIA5901") of Xylella fastidiosa Associated with Almond Leaf Scorch Disease in Alicante, Spain
Get PDFAn outbreak of Xylella fastidiosa subsp. multiplex sequence type ST6 was discovered in 2017 in mainland Spain affecting almond trees. Two cultured almond strains, "ESVL" and "IVIA5901," were subjected to high throughput sequencing and the draft genomes assembled. Phylogenetic analysis conclusively indicated they belong to the subspecies multiplex, and pairwise comparisons of the chromosomal genomes showed an average nucleotide identity higher than 99%. Interestingly, the two strains differ for the presence of the plasmids pXF64-Hb_ESVL and pUCLA-ESVL detected only in the ESVL strain. The availability of these draft genomes contribute to extend the European genomic sequence dataset, a first step toward setting new research to elucidate the pathway of introduction and spread of the numerous strains of this subspecies so far detected in Europe
Reprogramming of Retrotransposon Activity during Speciation of the Genus Citrus.
Get PDFSpeciation of the genus Citrus from a common ancestor has recently been established to begin 8Ma during the late Miocene, a period of major climatic alterations. Here, we report the changes in activity of Citrus LTR retrotransposons during the process of diversification that gave rise to the current Citrus species. To reach this goal, we analyzed four pure species that diverged early during Citrus speciation, three recent admixtures derived from those species and an outgroup of the Citrus clade. More than 30,000 retrotransposons were grouped in ten linages. Estimations of LTR insertion times revealed that retrotransposon activity followed a species-specific pattern of change that could be ascribed to one of three different models. In some genomes, the expected pattern of gradual transposon accumulation was suddenly arrested during the radiation of the ancestor that gave birth to the current Citrus species. The individualized analyses of retrotransposon lineages showed that in each and every species studied, not all lineages follow the general pattern of the species itself. For instance, in most of the genomes, the retrotransposon activity of elements from the SIRE lineage reached its highest level just before Citrus speciation, while for Retrofit elements, it has been steadily growing. Based on these observations, we propose that Citrus retrotransposons may respond to stressful conditions driving speciation as a part of the genetic response involved in adaptation. This proposal implies that the evolving conditions of each species interact with the internal regulatory mechanisms of the genome controlling the proliferation of mobile elements
Survival analysis of orange tree varieties in Spain
Get PDFThe fundamental basis of Spanish citriculture is its varietal composition, which contributes to the existence of a marketing calendar that extends to almost the entire year. As time goes by, the supply of varieties is continuously renewed, requiring significant investments by growers. The guarantee of a quality supply to the markets, on one hand, and the optimal result of the investments made, on the other, require that, in managing the sector, the characteristics determining the survival of the varieties be taken into account. The main purpose of this study was therefore to assess the influence of the attributes affecting the longevity of orange plantations from a technical and commercial point of view. The duration analysis technique applied to the different varieties has been used. The main attributes determining the elimination of a variety were the presence of seeds in the fruit and the tendency towards a decrease in surface size. Permanence- or survival-friendly attributes included the calibre (large size of the variety, within its group) and the price received by farmers. Precocity, frost resistance, commercial quality and resistance to fruit fly did not have the expected level of significance
Validación de CitrusVol para el ajuste de volúmenes de caldo en tratamientos contra araña roja en cítricos
Get PDFPara optimizar la aplicación de fitosanitarios, el IVIA ha desarrollado una
herramienta de recomendación de volumen de caldo para las aplicaciones mediante
turboatomizadores en cítricos: CitrusVol. Esta herramienta permite ajustar el volumen de
caldo a las características del cultivo, al tipo de plaga o enfermedad y al tipo de producto
fitosanitario. El objetivo de este trabajo fue validar CitrusVol para el control de la araña roja,
Tetranychus urticae Koch, en clementinos, dado que es una de las principales plagas del cultivo.
Para ello, se compararon los tratamientos fitosanitarios siguiendo las recomendaciones de
CitrusVol con los tratamientos realizados de manera convencional por la explotación. Se
evaluó, por un lado, la distribución del caldo en la copa estimando el porcentaje de
recubrimiento. Por otro lado, se determinó la eficacia de los tratamientos, para lo que se
realizaron muestreos previos y posteriores a los tratamientos fitosanitarios y se determinó el
porcentaje de hojas sintomáticas ocupadas por araña. Los resultados mostraron que con el
empleo de CitrusVol se consiguió una reducción media del volumen de caldo de 33,5 %, lo que
implicó una reducción del recubrimiento con el volumen ajustado respecto al convencional.
Sin embargo, no se encontraron diferencias significativas en el porcentaje de hojas sintomáticas
ocupadas por araña roja en función del volumen de caldo aplicado. Esto permite concluir que
la eficacia fue la misma y que el volumen recomendado por CitrusVol es adecuado para el
control de esta plaga en clementinos
Comparacion de jaulas de maternidad con plataforma frente a jaulas convencionales en una prueba de campo
Get PDFLa utilización de una jaula de mayores dimensiones y con plataforma (Pl) se ha comparado con las jaulas
utilizadas (Es) en dos explotaciones comerciales, utilizando 56 conejas en cada grupo durante 6 ciclos productivos.
Los resultados indican pocas diferencias productivas entre los dos tipos de jaulas, pero algunas de
ellas relevantes. La mortalidad de gazapos en el nido fue mayor en Pl que en Es (11% vs. 9,1%), así como la
pérdida total de camadas (5,6% vs. 2,6%), el peso del gazapo al destete fue menor (1005g vs. 1032g) y el
índice de conversión en lactación aumentó (2,9 vs. 2,5). Un mayor número de conejas se mostraron agresivas
en Pl que en Es (2,2% vs. 0,4%) cuando eran manipuladas y más jaulas estaban sucias y necesitaron limpieza
durante cada ciclo (13% vs. 0,9%)