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Influencia del riego deficitario en olivar superintensivo cv Arbequina sobre el perfil fenólico y de ácidos grasos del aceite de oliva virgen
Get PDFLas plantaciones superintensivas de olivo han
experimentado un aumento durante los últimos años
debido a la posibilidad de mecanizar las prácticas
culturales, siendo la variedad Arbequina la más extendida
para este tipo de cultivos. El objetivo de este trabajo es
estudiar el impacto del riego deficitario controlado (RDC)
frente a un riego completo en plantaciones superintensivas
de olivo cv. Arbequina, sobre el perfil fenólico y de ácidos
grasos de los aceites elaborados. En este estudio se
cuenta con plantaciones de distintas zonas de olivar
(Catalunya y Comunidad Valenciana, Navarra y Madrid).
Los resultados obtenidos en el estudio, que incluye los
datos de una campaña, no revelan una influencia del RDC
sobre el perfil fenólico o la composición de ácidos grasos
de los aceites. No obstante, se ponen de manifiesto
diferencias importantes en la composición fenólica y de
ácidos grasos de los aceites monovarietales de Arbequina
en función de la zona de cultivo. Se confirma el hecho de
que la composición química del aceite de oliva virgen está
influenciada en gran medida por la zona geográfica de
producción, existiendo una importante interacción
cultivar/ambiente
Orius laevigatus Induces Plant Defenses in Sweet Pepper
Get PDFPest management in protected sweet pepper crops primarily relies on biological control
strategies. The release of the phytoseiid Amblyseius swirskii Athias-Henriot (Acari:
Phytoseiidae) and the anthocorid Orius laevigatus Fieber (Hemiptera: Anthocoridae)
provides effective control of the two key pests of this crop, the thrips Frankliniella
occidentalis Pergande (Thysanoptera: Thripidae) and the whitefly Bemisia tabaci
Gennadius (Hemiptera: Aleyrodidae) (Sanchez et al., 2000; Calvo et al., 2009; van der
Blom et al., 2009). A part of their direct effect on pest predation, zoophytophagous
predators may induce defensive plant responses due to their plant feeding behaviour which
involves the release of diverse volatiles through different pathways that are triggered by
phytohormones (De Puysseleyr et al., 2011; Naselli et al., 2016; Pappas et al., 2015, 2016;
Pérez-Hedo et al., 2015a,b). These responses may result in the repellence or attraction of
pests and natural enemies. It is hence hypothesized that O. laevigatus would be able to
induce plant responses in sweet pepper as has been demonstrated in other plantzoophytophage systems. As a first step to better understand the interaction between O.
laevigatus and sweet pepper, the behavior of O. laevigatus on the plants was studied and
plant feeding behaviour quantified to compare general behaviors. Orius laevigatus spends
the majority of its time (38%) feeding on apical meristems and apical fresh leaves, which
were also preferred residence locations (Bouagga et al., 2017)
Systemic resistance in citrus to Tetranychus urticae induced by conspecifics is transmitted by grafting and mediated by mobile amino acids
Get PDFRecent research suggests that systemic signalling and communication between roots and leaves plays an important role in plant defence against herbivores. In the present study, we show that the oviposition of the two-spotted spider mite Tetranychus urticae in the systemic leaves of citrus rootstock Citrus aurantium (sour orange) was reduced by 50% when a lower leaf was previously infested with conspecifics. Metabolomic and gene expression analysis of the root efflux revealed a strong accumulation of glutamic acid (Glu) that triggered the expression of the citrus putative glutamate receptor ( GRL ) in the shoots. Additionally, uninfested sour orange systemic leaves showed increased expression of glutamate receptors and higher amounts of jasmonic acid (JA) and 12-oxo-phytodienoic acid in plants that were previously infested. Glu perception in the shoots induced the JA pathway, which primed LOX-2 gene expression when citrus plants were exposed to a second infestation. The spider mite-susceptible citrus rootstock Cleopatra mandarin ( C. unshiu ) also expressed systemic resistance, although the resistance was less effective than the resistance in sour orange. Surprisingly, the mobile signal in Cleopatra mandarin was not Glu, which suggests a strong genotype-dependency for systemic signalling in citrus. When the cultivar Clemenules ( C. clementina ) was grafted onto sour orange, there was a reduction in symptomatic leaves and T. urticae populations compared to the same cultivar grafted onto Cleopatra mandarin. Thus, systemic resistance is transmitted from the roots to the shoots in citrus and is dependent on rootstock resistance
Comparative Genomic and Phenotypic Characterization of Pathogenic and Non-Pathogenic Strains of Xanthomonas arboricola Reveals Insights into the Infection Process of Bacterial Spot Disease of Stone Fruits
Get PDFXanthomonas arboricola pv. pruni is the causal agent of bacterial spot disease of stone fruits, a quarantinable pathogen in several areas worldwide, including the European Union. In order to develop efficient control methods for this disease, it is necessary to improve the understanding of the key determinants associated with host restriction, colonization and the development of pathogenesis. After an initial characterization, by multilocus sequence analysis, of 15 strains of X. arboricola isolated from Prunus, one strain did not group into the pathovar pruni or into other pathovars of this species and therefore it was identified and defined as a X. arboricola pv. pruni look-a-like. This non-pathogenic strain and two typical strains of X. arboricola pv. pruni were selected for a whole genome and phenotype comparative analysis in features associated with the pathogenesis process in Xanthomonas. Comparative analysis among these bacterial strains isolated from Prunus spp. and the inclusion of 15 publicly available genome sequences from other pathogenic and non-pathogenic strains of X. arboricola revealed variations in the phenotype associated with variations in the profiles of TonB-dependent transporters, sensors of the two-component regulatory system, methyl accepting chemotaxis proteins, components of the flagella and the type IV pilus, as well as in the repertoire of cell-wall degrading enzymes and the components of the type III secretion system and related effectors. These variations provide a global overview of those mechanisms that could be associated with the development of bacterial spot disease. Additionally, it pointed out some features that might influence the host specificity and the variable virulence observed in X. arboricola
An Integrated View of Whole-Tree Hydraulic Architecture. Does Stomatal or Hydraulic Conductance Determine Whole Tree Transpiration?
Get PDFHydraulic conductance exerts a strong influence on many aspects of plant physiology, namely: transpiration, CO2 assimilation, growth, productivity or stress response. However we lack full understanding of the contribution of root or shoot water transport capacity to the total water balance, something which is difficult to study in trees. Here we tested the hypothesis that whole plant hydraulic conductance modulates plant transpiration using two different seedlings of citrus rootstocks, Poncirus trifoliata (L.) Raf. and Cleopatra mandarin (Citrus reshni Hort ex Tan.). The two genotypes presented important differences in their root or shoot hydraulic conductance contribution to whole plant hydraulic conductance but, even so, water balance proved highly dependent on whole plant conductance. Further, we propose there is a possible equilibrium between root and shoot hydraulic conductance, similar to that between shoot and root biomass production, which could be related with xylem
anatomy
A review on the Tephritid fruit flies of economic interest in Cuba: species, plant hosts, surveillance methods and management program implementation
Get PDFThe presence of several Tephritid species in Cuba required of special surveillance methods to determine the free-pest zone or at least to determine the exact species inhabiting the island and the economical repercussion that could affect to the export market. Our previous studies of surveillance, monitoring and training methods set up the protocols for an area-wide fruit fly management irrespectively of the fruit species. In this work, we upgraded the surveillance of Anastrepha species in export commodities and in other crops. Methods: Several commodities (fruit varieties) were sampled including not host fruits. A deep surveillance of citrus was also included. Collected infested fruits were retrieved to the laboratory to allow larva development to identify emerged adults to species level. Monitoring traps were also used in citrus plots to confirm the Anastrepha suspensa-free status of this commodity. Results: Monitoring traps allowed to confirm the presence of different Anastrepha species in Cuba namely A. suspensa, A. soroana, A. obliqua, A. ocresia, A. insulae and A. interrupta, and also Toxotrypana curvicauda. An additional species, belonging to Anastrepha genus, A. sp., was also recorded, not matching any described species. Fruit fly major population peak was found to fit with ripening season of stone fruits and other non-citrus fruits. Following the surveillance of tephritid larva' infested fruits, five new host species were confirmed for Anastrepha suspensa: sapodilla, rose apple, cocoplum, custard apple, and gac fruit. And two new ones for Anastrepha obliqua: the cocoplum and yellow mombin. Citrus surveillance was clear, no tephritid fruit fly was found in any Citrus species in all along Cuba Island. Conclusions: The absence of fruit flies in citrus commodities reveals the success of the implemented management program including surveillance, monitoring and personnel training, putting into value the area-wide Cuban fruit fly management program for Anastrepha species
Comparative Study of Bioactive Components and Quality from Juices of Different Mandarins: Discriminant Multivariate Analysis of Their Primary and Secondary Metabolites
Get PDFA comparative study of the primary and secondary metabolites of the juice of several mandarin cultivars with different pollination, seed production and parthenocarpic abilities was carried out, and the antioxidant capacity of the hydrophilic fraction was measured. Correlation by a Principal Component Analysis and a Cluster Analysis was used. By a multivariate analysis, the 15 citrus cultivars were clustered into four groups consistently with citrus types. The presented data are an important factor for choosing varieties with high potential as a nutraceutical source. These aspects are necessary as consumers demand prevention of health problems through nutrition and certain fruit quality traits, including fruit size, internal quality, good rind color and easy peeling
Synergism between potassium sorbate dips and brief exposure to high CO2 or O-2 at curing temperature for the control of citrus postharvest green and blue molds
Get PDFSynergistic effects and very effective control of citrus postharvest green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, were observed on artificially inoculated ‘Valencia’ oranges and ‘Clemenules’ and ‘Ortanique’ mandarins after a potassium sorbate (PS) treatment was followed by 2 days of storage in atmospheres of elevated CO2 or O2 at a curing temperature. A combined treatment consisting of 60-s dips in aqueous solutions of 3% PS heated to 62 °C was followed by 48-h exposure to air, 15 kPa CO2 or 30 kPa O2 at 33 °C. Control treatment was a 60-s water dip at 20 °C followed by 24-h exposure to air at 20 °C. Synergism was observed on citrus fruit either incubated at 20 °C for up to 22 days, simulating direct commercialization, or stored at 5 °C for up to 45 days, simulating commercial cold storage. This research offers potential new tools to the citrus industry for implementation of nonpolluting integrated postharvest disease management programs, especially devoted to high added value organic markets or export markets with zero residue tolerance
‘HoneySweet’ (C5), the First Genetically Engineered Plum pox virus–resistant Plum (Prunus domestica L.) Cultivar
Get PDFOrigin
‘HoneySweet’ originated as a seedling from the open pollination of ‘Bluebyrd’ plum (Scorza and Fogle, 1999). The pollen parent of ‘HoneySweet’ is unknown. ‘HoneySweet’ was originally selected in vitro as a regenerated shoot from a hypocotyl slice that had been transfected with Agrobacterium tumefaciens EHA 101 carrying the plasmid pGA482GG/PPV-CP-33 (Scorza et al., 1994). The regenerated, transgenic shoot, coded as C5, along with other transgenic shoots, was rooted in vitro and transferred to a greenhouse. Following greenhouse testing using graft and aphid inoculations with the M and D strains of Plum pox virus (PPV), C5 (later patented as ‘HoneySweet’), was asexually propagated by bud grafting on to standard rootstocks, including Prunus persica (GF305 peach seedlings), Prunus domestica (European plum seedlings), Prunus myrobalan, and GF 8-1 (Prunus cerasifera × P. munsoniana). An overview of the development of ‘HoneySweet’ plum and molecular characterization can be found in Scorza et al. (2013a)
Electrical Conductivity Measurements in Agriculture: The Assessment of Soil Salinity
Get PDFSoil salinity is an important issue constraining the productivity of irrigation agriculture
around the world. The standard method for soil salinity assessment is based on a laboratory
method that is cumbersome and gives rise to limitations for data-intensive works. The
use of sensors for the assessment of the apparent electrical conductivity (EC) of soils offers
a way to overcome these constraints. These sensors are based on three electromagnetic
phenomena, namely, electrical resistivity, electromagnetic induction, and reflectometry.
Each class of sensors presents its own advantages and drawbacks. In the following
chapter, these are presented along with the most popular commercial EC sensors used in
nowadays agriculture, equations for the assessment of soil salinity on basis sensor
measurements, some examples of application, and present and future development
trends