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Acta Horticulturae
No full textIncrease of productivity is crucial for the Spanish production of oranges and mandarins destined for the fresh market. Harvest and handling operations represent 50% of the field production costs. Fruits are currently manually harvested, loaded in boxes and transported to a packinghouse where fruit are sorted. In the early season, sorting is aimed at color classification and in the mid and late season, oranges and mandarins are sorted by size. The present work shows the development of an automatic sorting system capable of separating citrus fruit in three user-defined color or weight categories while fruit are harvested. Limited energy and space availability have been critical issues for the electronic and mechanical designs. All the subsystems are commanded by a central unit that can be easily adapted to each orchard and is operated by one worker. The current version of the machine has a throughput of eight fruit per second and has successfully worked in the field during one Spanish harvesting season (September-June)
Gene expression analysis of chilling requirements for flower bud break in peach
No full textDormancy has been defined as the inability to initiate growth from meristem under favourable environmental conditions. The length of dormancy is a genotype-specific trait that limits the climatic adaptability of temperate crops, as peach. A better knowledge of the genes involved in dormancy may provide genetic tools for an early assessment of the trait in breeding programmes. Recent studies on the molecular aspects of dormancy provided an initial description of candidate genes involved in bud dormancy maintenance and release in peach. In this paper, we compare the chilling requirement for dormancy release of five peach cultivars with the expression of five genes and ESTs related to bud dormancy: DAM5, DB396 (ppa007606m), DB247 (ppa012188m), SB280 (ppa006974m) and PpB63 (ppa008309m). Results indicated that gene expression analysis could contribute to estimate the chilling requirement for dormancy release of new cultivars
Expresión de genes relacionados con la respuesta a estrés hídrico en frutales de hueso (Prunus spp)
Get PDFLos frutales de hueso (Prunus spp.) difieren en cuanto a su comportamiento frente a
determinados estreses medioambientales. En este trabajo se ha estudiado la respuesta
a la sequía en dos genotipos utilizados como portainjertos en distintas condiciones de
suelos. El híbrido almendro x melocotonero (P. amygdalus x P. persica) ‘Garnem’ y su descendiente
el trihíbrido ‘P.2175’ x ‘Garnem’-3 (P. cerasifera x [P. amygdalus x P. persica]).
Ambos se sometieron a un periodo de déficit hídrico durante un mes, seguido de un periodo
de recuperación en umbráculo. El tratamiento de estrés se realizó manteniendo las
plantas a un contenido de humedad del sustrato del 35%. Se tomaron datos fisiológicos a
los 0, 10 y 15d de estrés y a los 10d y 15d de recuperación. Igualmente se estudio la expresión
de dos genes en dos tejidos diferentes, que codifican para proteínas relacionadas
con el ABA y el estrés abiótico, una dehidrina y una proteína de unión a zinc respectivamente.
Los parámetros fisiológicos de conductancia estomática y de potencial hídrico
fueron monitorizados y correlacionados con la expresión génica. Se observó que existe
una relación inversa entre los parámetros fisiológicos y moleculares. La relación de ambos
parámetros y su implicación en la mejora de la tolerancia a este estrés será discutida
Evaluación de los efectos sobre la calidad del suelo generado por la modalidad de gestión de los restos de cultivo en agrosistemas ecológicos e integrados de hortícolas en la Comunidad Valenciana
Get PDFPara la realización de este trabajo se han utilizado muestras de suelo tomadas durante 2009 y 2011, a tres profundidades (0-15, 16-30 y 31-60 cm) procedentes de las parcelas elementales del ensayo establecido en la finca experimental de Ruralcaja, Grupo CRM, en Paiporta (Valencia), en el año 1998, en el marco del proyecto europeo (VEGINECO). Este estudio durante los tres primeros años estuvo centrado en la comparación de la producción ecológica e integrada de hortalizas en base a parámetros
productivos, cualitativos y edáficos, y posteriormente se continuó dentro del Programa I+D de la Conselleria de Agricultura, Generalitat Valenciana. En este trabajo se presentan los resultados correspondientes a las propiedades físicoquímicas y biológicas del suelo en función del sistema de producción (ecológico versus integrado), y de la modalidad de gestión de los restos de cultivo (incorporación inmediata, incorporación diferida y recogida) de diferentes rotaciones de hortalizas.
En cuanto a la comparación de los dos agrosistemas, se encontraron diferencias significativas, a nivel estadístico (p<0,05), en algunos parámetros relevantes del suelo como la materia orgánica, el nitrógeno orgánico, el nitrato asimilable, el hierro asimilable y el porcentaje de agua retenida por el suelo, correspondiendo en todos los casos los valores más altos al sistema ecológico. Por otra parte, la incorporación de la biomasa correspondiente a los restos de cosecha (en las dos modalidades, RC1 y RC3) respecto a la recogida de los mismos (RC2), mejoró considerablemente la calidad del suelo, encontrándose aumentos significativos en los niveles de nutrientes asimilables (nitrógeno, fósforo y potasio) e indicadores biológicos del suelo
Deep sequencing revealed genome-wide single-nucleotide polymorphism and plasmid content of Erwinia amylovora strains isolated in Middle Atlas, Morocco
No full textErwinia amylovora causes economic losses that affect pear and apple production in Morocco. Here, we report comparative genomics of four Moroccan E. amylovora strains with the European strain CFBP1430 and North-American strain ATCC49946. Analysis of single nucleotide polymorphisms (SNPs) revealed genetic homogeneity of Moroccan's strains and their proximity to the European strain CFBP1430. Moreover, the collected sequences allowed the assembly of a 65 kpb plasmid, which is highly similar to the plasmid pEI70 harbored by several European E. amylovora isolates. This plasmid was found in 33% of the 40 E. amylovora strains collected from several host plants in 2009 and 2010 in Morocco
Simultaneous detection of the seven main tomato-infecting RNA viruses by two multiplex reverse transcription polymerase chain reactions
Get PDFCucumber mosaic virus, Tomato spotted wilt virus, Tomato mosaic virus, Tomato chlorosis virus, Pepino mosaic virus, Torrado tomato virus and Tomato infectious chlorosis virus cause serious damage and significant economic losses in tomato crops worldwide. The early detection of these pathogens is essential for preventing the viruses from spreading and improving their control. In this study, a procedure based on two multiplex RT-PCRs was developed for the sensitive and reliable detection of these seven viruses. Serial dilutions of positive controls were analysed by this methodology, and the results were compared with those obtained by ELISA and singleplex versions of RT-PCR. The multiplex and singleplex RT-PCR assays were able to detect specific targets at the same dilution and were 100 times more sensitive than ELISA. The multiplex versions were able to detect composite samples containing different concentrations of specific targets at ratios from 1:1 to 1:1000. In addition, 45 symptomatic tomato samples collected in different tomato-growing areas of Sicily (Italy) were analysed by multiplex RT-PCR, singleplex RT-PCR and commercially available ELISA tests. Similar results were obtained using the RT-PCR techniques, with a higher sensitivity than ELISA, revealing a common occurrence of mixed infections and confirming the presence of these seven virus species in Italy. (C) 2012 Elsevier B.V. All rights reserved
Usefulness of maximum diurnal trunk shrinkage as a continuous water stress indicators of pomegranate (Punica granatum) trees
Get PDFThe objective of this research was to asses the feasibility of using maximum diurnal trunk shrinkage (MDS) obtained by means of LVDT sensors, as a plant water stress indicators for pomegranate trees. The experiment was carried out with mature trees grown in the field under three irrigation regimes: (I) control (well watered trees); (II) trees continuously deficit irrigated at 50% of the control regime (SDI); and (III) trees that had a summer water stress cycle being irrigated at 25% of the control rates only in July and August (RDI). Control trees maintained lower MDS values than the SDI ones. In the RDI treatment, as water restrictions began, there was a slow increase in MDS, in correspondence with a decrease in stem water potential (Ψstem). When water was returned at full dosage, the RDI recovered to MDS and Ψstem values similar to the control. However, lower MDS for a given values were observed as the season advanced. The magnitude of differences between well watered and deficit irrigated trees was much larger in the case of MDS than for Ψstem. The tree-to-tree variability of the MDS readings was more than four times higher than for Ψstem
Optimización de la eficiencia de uso del nitrógeno en cítricos para el desarrollo de una agricultura sostenible. II. Comparación fertilización mineral y orgánica en riego localizado.
Get PDFEn la actualidad se están modificando las prácticas agrícolas actuales orientándolas hacia sistemas alternativos de producción agrícola asumiendo, por tanto, compromisos de respeto medioambiental. Así, la agricultura ecológica se presenta como alternativa a la agricultura tradicional. Los residuos generados por las zonas agrícolas y las granjas agropecuarias, mediante un adecuado manejo, podrían ser fuente importante de nutrientes para las plantas. El propósito de este estudio consistió en comparar la absorción del nitrógeno aplicado a plantas de cítricos, mediante abonos orgánicos obtenidos de residuos vegetales y estiércol de oveja, a los que se incorporó el isótopo estable 15N, frente a fertilizantes minerales ampliamente utilizados en una agricultura tradicional. Las plantas fertilizadas con abonos orgánicos presentaron una biomasa final superior a los que recibieron fertilizantes minerales. Sin embargo, tanto la concentración como el contenido de N total y la eficiencia de uso del N aplicado fue similar en las plantas fertilizadas con ambos abonos (mineral frente orgánico). La contribución del N procedente de los fertilizantes orgánicos al contenido en N total de los órganos jóvenes y viejos de la parte aérea de la planta fue notablemente inferior que la proporcionada por los fertilizantes minerales. Por tanto, los fertilizantes de procedencia orgánica presentaron una respuesta agronómica similar a la obtenida con los fertilizantes minerales tradicionales
A Non-Targeted Approach Unravels the Volatile Network in Peach Fruit
Get PDFVolatile compounds represent an important part of the plant metabolome and are of particular agronomic and biological interest due to their contribution to fruit aroma and flavor and therefore to fruit quality. By using a non-targeted approach based on HS-SPME-GC-MS, the volatile-compound complement of peach fruit was described. A total of 110 volatile compounds (including alcohols, ketones, aldehydes, esters, lactones, carboxylic acids, phenolics and terpenoids) were identified and quantified in peach fruit samples from different genetic backgrounds, locations, maturity stages and physiological responses. By using a combination of hierarchical cluster analysis and metabolomic correlation network analysis we found that previously known peach fruit volatiles are clustered according to their chemical nature or known biosynthetic pathways. Moreover, novel volatiles that had not yet been described in peach were identified and assigned to co-regulated groups. In addition, our analyses showed that most of the co-regulated groups showed good intergroup correlations that are therefore consistent with the existence of a higher level of regulation orchestrating volatile production under different conditions and/or developmental stages. In addition, this volatile network of interactions provides the ground information for future biochemical studies as well as a useful route map for breeding or biotechnological purposes
Acta Horticulturae
No full textA population of several Banksia species, mainly B. ashbyi, B. integrifolia, B. praemorsa and B. prionotes propagated by seed was characterized at the Estacion Experimental Agraria de Elche (IVIA), Spain. Considerable levels of morphological variability were observed, especially in relation to their adaptation to the local alkaline soils. Since selection and breeding is difficult due to the long growing cycle of this perennial shrub, it would be desirable to use molecular markers in order to estimate genetic diversity. Thirty well adapted 12-year-old individuals were selected namely, ten individuals of B. integrifolia, ten of B. prionotes, five of B. ashbyi and five of B. praemorsa respectively. In addition, eight young plants that originated from seed of a single 12-year-old B. integrifolia plant were also analyzed to evaluate the genetic diversity within the offspring of a single plant. The well known RAPD technique and another marker technique based on tubulin polymorphism (TBP) were used. Genetic diversity was detected in the individuals analyzed, even though these individuals had been previously selected for their adaptive ability to local conditions. Interestingly, edaphic conditions of the experimental site where the plants have been cultivated for 12 years were considered not very suitable for Banksia species. However, apparently enough variability seemed to be present to guarantee that genetic selection is possible