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Chlorophyll fluorescence imaging can reflect development of vascular connection in grafting union in some Solanaceae species
Get PDFGraft union development in plants has been studied mainly by destructive methods such as histological studies. The aim of this work was to evaluate whether the chlorophyll fluorescence imaging (CFI) technique is sensitive enough to reflect changes at the cellular level in different Solanaceae grafted plants 30 d after grafting, when both grafted partners were well fused and strong enough in all plant combinations. The pepper cultivar 'Adige' was grafted onto different Capsicum spp. accessions typified with different compatibility degrees; eggplant was grafted on Solanum torvum and pepper homografts as compatible unions; pepper was grafted on S. torvum and on tomato as incompatible unions. 'Adige'/'Adige' and 'Adige'/pepper A25 showed a higher maximum quantum efficiency of PSII associated with higher values of actual quantum efficiency of PSII and photochemical quenching as well as with vascular regeneration across the graft interface. Our results highlighted that CFI changes reflected histological observations in grafted Solanaceae plants
Effect of antibrowning dips and controlled atmosphere storage on the physico-chemical, visual and nutritional quality of minimally processed "Rojo Brillante" persimmons
Get PDFThe combined effect of antibrowning dips and controlled atmosphere storage on fresh-cut Rojo Brillante persimmon quality was investigated. Persimmon slices were dipped in 10gL(-1) ascorbic acid, 10gL(-1) citric acid or water and were stored in different controlled atmospheres at 5?. Controlled atmosphere conditions were 21kPa O-2+10kPa CO2 (Atm-B), 21kPa O-2+20kPa CO2 (Atm-C), 5kPa O-2+10kPa CO2 (Atm-D) and 5kPa O-2 in the absence of CO2 (Atm-E). Air (Atm-A) was used as a control. Atmospheres with high CO2 concentrations induced darkening, associated with a flesh disorder known as internal flesh browning. Only the samples placed in Atm-E, and treated with 10gL(-1) ascorbic acid or 10gL(-1) citric acid, controlled enzymatic browning, reduced firmness loss and prevented the internal flesh browning disorder. The maximum limit of marketability was achieved in the samples treated with 10gL(-1) citric acid and stored in Atm-E for nine storage days at 5?. The total vitamin C, free radical scavenging activity, total phenolic content and total carotenoids of the fresh-cut Rojo Brillante persimmons were affected by maturity stage at harvest, whereas antibrowning dips and controlled atmosphere storage had no clear effect
The impact of adult diet on parasitoid reproductive performance
Get PDFDiet is one of the most common influences on parasitoid reproductive traits. The life span, mating ability, fecundity, fertility and sex ratio of parasitoids can be affected by the quality of the adult diet. In the field, parasitoids can rely on different hosts and non-host nutrient sources, such as floral and extrafloral nectar, hemipteran honeydew and pollen, and various artificial diets have been used in mass rearing. In addition, some parasitoid species obtain nutrients by feeding on their host while adult (host feeding). In this review, we summarize current knowledge on the impact of the adult diet on the reproductive behavior of hymenopteran and dipteran parasitoids, with a particular focus on longevity, offspring production and host searching traits. First, we focus on food preferences and learning abilities of parasitoids to discriminate high-quality diets. Second, we analyze the impact of the adult diet on longevity, examining different natural and artificial food sources as well as the effect of their concentration and frequency. Third, we highlight the impact of the adult diet on host foraging. Fourth, we review the impact of adult diet on parasitoid offspring with special reference to (1) egg load, maturation and resorption, (2) parasitism and (3) progeny production and sex ratio. Finally, a number of implications for biological control and integrated pest management are discussed
Caracterización agronómica-morfológica de 6 entradas de “tomaca tipo masclet” de la colección de variedades tradicionales del IVIA
Get PDFEn el presente trabajo se muestran las características morfológicas y
de interés agronómico del fruto, correspondientes a 6 entradas de tomate
valenciano perteneciente a la colección de variedades tradicionales del
IVIA. Las 6 entradas son: IVIA-2 (origen Moncada); IVIA-27 (origen Siete
Aguas); IVIA-28 (origen Paiporta); IVIA-69 (origen Moncada); IVIA-72
(origen Moncada); IVIA-126 (origen El Perelló). Respecto a la arquitectura
de la planta, las 6 entradas son similares. La diferencia más importante entre
ellas es debido a la morfología del fruto; tanto en su sección longitudinal,
número de lóculos y el peso medio de los frutos. Las entradas con el
extremo distal del fruto con forma puntiaguda, característica muy apreciada
por los consumidores, son las IVIA-27 e IVIA-69. Por otro lado, IVIA-28,
presenta el mayor peso medio de los frutos con un valor de 262g con una
gran calidad, aunque la forma del fruto es menos puntiaguda que ninguno de
los otros. Las 6 entradas presentan un gran potencial agronómico dado que
presentan un tamaño, forma y color de fruto atrayentes dentro de los
cánones de la denominación del tomate valenciano
Within‐plant distribution of Phorodon humuli (Hemiptera: Aphididae) and natural enemies on hops with implications for sampling and management
No full textA field trial was performed on a hop yard throughout 2006, 2007 and 2008 in order to analyze the within‐plant distribution of Phorodon humuli (Schrank) and its natural enemies. The aphid population was higher on the leaves of the middle section of the main stem. Specifically, the population was significantly higher at 2 and 3.25 m than at 6 m during the three years. Natural enemies consisted of aphidophagous predators of which Coccinella septempunctata was recorded in the highest number. Its number was greater where the aphid population was higher, with a significantly higher number of eggs, larvae and adults at 2 and 3.25 m than at 6 m. Lacewing eggs were also frequently observed, with a significantly higher population where the number of aphids was higher. The number of winged aphids was higher at 3.25 m than at 2 m within a plant. Understanding hop aphid distribution within the hop canopy is important in developing sampling programs, in evaluating injury and helps the development of sustainable management practices
Xylella fastidiosa en la Comunidad Valenciana
Get PDFEn junio de 2016, la Generalitat Valenciana aprobó el Plan de Contingencia Autonómico frente a X. fastidiosa, basado en el Plan de Contingencia Nacional, pero adaptado a las características y cultivos específicos de la Comunidad Valenciana. Este plan ha sido revisado en enero del 2017, incrementándose considerablemente las intensidades de prospección en los principales cultivos de nuestra comunidad autónoma (cítricos, viña, olivo, Prunus spp. y plantas ornamentales) así como en la gran cantidad de empresas inscritas en nuestros registros como proveedores de material vegetal de reproducción y también en parques y jardines de titularidad pública y privada, todos ellos considerados como puntos críticos de riesgo de introducción de la bacteria en nuestro territorio. Con estas directrices, se han realizado más de 2.000 prospecciones entre 2015 y junio de 2017, principalmente en zonas de mayor riesgo climático para el establecimiento de la enfermedad, como se señala en
la Figura 1. De las prospecciones de material vegetal citadas, en 2015 se analizaron 468 muestras procedentes de viveros y de plantaciones en el Laboratorio de Diagnóstico Fitopatológico (LDF), que es el laboratorio oficial de la Comunidad Valenciana en materia de sanidad vegetal, pertenecientes a especies diferentes (naranjo, mandarino, pomelo, cítricos híbridos, olivo, almendro, vid, adelfa, Choisya ternata y Polygala myrtifolia). En 2016 se analizaron 423 muestras, entre las que se incluyeron nuevas especies, además de las anteriormente citadas (limonero, kumquat, cafeto, ciruelo, albaricoquero, cerezo, laurel, romero, Prunus mahaleb y Quercus ilex). Todas estas muestras dieron resultados negativos para la detección de X. fastidiosa
Laboratory-scale evaluation of composite spiked samples for erwinia amylovora detection in asymptomatic plants
No full textErwinia amylovora, the fire blight pathogen, can survive in plants and produce latent infections that can lead to false negative results in routine diagnostic procedures, since the pathogen can be present at very low numbers under the detection limit of available techniques. A protocol combining different techniques included in the EPPO diagnostic standard for E. amylovora (2013) was designed in order to determine the minimum amount of plants necessary for detecting the pathogen in asymptomatic plant material. To this aim, single samples of flowers and shoots from pear, apple, and loquat were spiked with an E. amylovora strain at different concentrations, and then analyzed by isolation, real-time PCR and ELISA-DASI. Thereafter, using the single spiked samples that were positive for any of the techniques used, composite spiked samples were prepared by adding to single spiked samples increasing amounts of plant material. Interestingly, whole results show that the most robust technique, less affected by the amount of plant material, was the real-time PCR after enrichment, since 101 -102 cfu ml-1 of E. amylovora could be detected in most cases, both in flowers and in shoots, regardless of the amount of simulated plants analyzed, 3, 5, 10 or 20. The enrichment was confirmed as a necessary step in the analysis of bulked samples to achieve a greater sensitivity. This study is a relevant contribution for programs of extensive screening surveys for prevention of fire blight disease, since it shows that samples can be processed as a pool, improving the detection of E. amylovora in asymptomatic samples
ICTV Virus Taxonomy Profile: Ophioviridae
Get PDFThe Ophioviridae is a family of filamentous plant viruses, with single-stranded negative, and possibly ambisense, RNA genomes of 11.3–12.5 kb divided into 3–4 segments, each encapsidated separately. Virions are naked filamentous nucleocapsids, forming kinked circles of at least two different contour lengths. The sole genus, Ophiovirus, includes seven species. Four ophioviruses are soil-transmitted and their natural hosts include trees, shrubs, vegetables and bulbous or corm-forming ornamentals, both monocots and dicots
Citrus viroids in tunisia: prevalence and molecular characterization
No full textA field survey was conducted in commercial orchards of Cap Bon region and at the INRAT citrus collection to identify the prevalence of citrus viroids in Tunisia. Samples were collected from 202 trees grafted on sour orange (Citrus aurantium L.) including 35 common mandarin and 40 Cassar clementine trees showing cachexia symptoms. Sequential PAGE (sPAGE) analysis and molecular hybridization using viroid-specific probes revealed that all plants were infected with at least two viroids. Citrus exocortis viroid (CEVd), hop stunt viroid (HSVd) and citrus dwarfing viroid (CDVd) were found to be widespread and accounted for 70.3%, 72.3% and 78.2% of the tested trees, respectively. Citrus bent leaf viroid (CBLVd) and citrus bark cracking viroid (CBCVd) were found in 28.2% and 3.0% of trees, respectively. The most frequent viroid combinations found were CEVd+HSVd+CDVd (34.7%) and HSVd+CDVd (22.3%). Other combinations such as CBLVd+HSVd+CDVd (12.9%), CEVd+CBLVd+HSVd (11.9%) and CEVd+CDVd (10.8%) were less frequent. CEVd and CDVd isolates were RT-PCR amplified, cloned and sequenced, then compared with sequences from other parts of the world deposited in GenBank. The three CEVd clones sequenced had 99% similarity with each other and shared ca. 99% similarity with those from Iran, Greece, and Syria. CDVd isolates were 100% similar and shared >96% similarity with other isolates from Brazil, Cyprus, Greece, Uruguay, Israel and Spain
