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Jouy C.,British Petroleum | Gandelin M.H.,British Petroleum | Guitouni C.,GEVES Le Magneraud | Pascal T.,French National Institute for Agricultural Research | And 17 more authors.
Acta Horticulturae | Year: 2012

Peach/nectarine is an important fruit tree crop in Europe and indeed worldwide. The registration of new cultivars, either for Plant Breeders' Rights or National Listing (PBR/NL) purposes in the European Union (EU), requires the completion of a distinctness, uniformity and stability (DUS) test in one of the EU Member States. The number of candidate cultivars and potentially required example cultivars entered for DUS testing is steadily increasing annually. Moreover, DUS testing of this type of tree crops requires the maintenance of large orchards, particularly with the aim of having a complete reference collection. In France, Hungary, Spain and Italy, peach tree breeding activity is characterized by an important number of cultivars available and a short turn-over of the cultivars. This situation will extend to new EU members states in the coming years, with the development of the European trade. However, although the diversification increases the number of segments, for each segment, new released cultivars are genetically closer and closer. The consequence is that it is now difficult in some cases to distinguish between cultivars. Clearly, developing means of "managing" reference collections is highly desirable in order to be able to compare candidate cultivars with the closest cultivars of common knowledge in the reference collections prior to planting them, and so reduce the number of cultivars that need to be grown, without eroding the strength of PBR and the relevance of DUS tests. Effective means of such a management include the definition of a standardised way to compare phenotypic data and to use molecular markers to eliminate the reference cultivars which do not need to be compared to the candidate cultivars. In peach tree, various molecular markers such as DNA microsatellites (SSR) have been developed and evaluated, but they have not yet been used for the characterization of large collections. Therefore, this project will generate a database compiling both phenotypic data, including standardised morphological descriptions and digital pictures, and a large data set of DNA profiles for 522 peach tree cultivars selected among the EU granted and listed cultivars. © ISHS 2012.

Tena A.,Instituto Valenciano Of Investigaciones | Wackers F.L.,Biobest | Wackers F.L.,Lancaster University | Heimpel G.E.,University of Minnesota | And 3 more authors.
Current Opinion in Insect Science | Year: 2016

One focus of conservation biological control studies has been to improve the nutritional state and fitness of parasitoids by adding nectar and artificial sugars to agroecosystems. This approach has largely overlooked the presence of honeydew, which is likely the primary carbohydrate source available to parasitoids in many agroecosystems. Over the last decade, it has been demonstrated that parasitoids often utilize this sugar source and there is evidence that honeydew can indirectly impact the population dynamics of herbivores through its nutritional value for parasitoids. The consumption of honeydew by parasitoids can shape direct and indirect interactions with other arthropods. The strength of these effects will depend on: first, parasitoid biology, second, the presence of other sugar sources (mainly nectar), third, the quality and quantity of the honeydew, and fourth, the presence and competitive strength of other honeydew consumers such as ants. The combination of these four factors is expected to result in distinct scenarios that should be analyzed for each agroecosystem. This analysis can reveal opportunities to increase the biocontrol services provided by parasitoids. Moreover, honeydew can be a resource-rich habitat for insect pathogens; or contain plant secondary chemicals sequestered by hemipterans or systemic insecticides toxic for the parasitoid. Their presence and effect on parasitoid fitness will need to be addressed in future research. © 2016 Elsevier Inc. All rights reserved.

Teresani G.R.,Instituto Valenciano Of Investigaciones | Bertolini E.,Instituto Valenciano Of Investigaciones | Alfaro-Fernandez A.,Polytechnic University of Valencia | Martinez C.,Instituto Valenciano Of Investigaciones | And 8 more authors.
Phytopathology | Year: 2014

A new symptomatology was observed in celery (Apium graveolens) in Villena, Spain in 2008. Symptomatology included an abnormal amount of shoots per plant and curled stems. These vegetative disorders were associated with 'Candidatus Liberibacter solanacearum' and not with phytoplasmas. Samples from plant sap were immobilized on membranes based on the spot procedure and tested using a newly developed real-time polymerase chain reaction assay to detect 'Ca. L. solanacearum'. Then, a test kit was developed and validated by intralaboratory assays with an accuracy of 100%. Bacterial-like cells with typical morphology of 'Ca. Liberibacter' were observed using electron microscopy in celery plant tissues. A fifth haplotype of 'Ca. L. solanacearum', named E, was identified in celery and in carrot after analyzing partial sequences of 16S and 50S ribosomal RNA genes. From our results, celery (family Apiaceae) can be listed as a new natural host of this emerging bacterium. © 2014 The American Phytopathological Society.

Caruso M.,University of Catania | Distefano G.,University of Catania | La Malfa S.,University of Catania | Gentile A.,University of Catania | And 3 more authors.
Acta Horticulturae | Year: 2012

Compared to what is known in model species, reproductive biology in citrus is still poorly understood. Although in recent years several efforts have been made to study pollen-pistil interaction and self-incompatibility, little information is available about the molecular mechanisms regulating these processes. Here we report the identification of candidate genes involved in pollen-pistil interaction and selfincompatibility in clementine (Citrus clementina Hort. ex Tan.). These genes have been identified comparing the transcriptomes of laser-microdissected stylar canal cells isolated from two clementine genotypes differing in their self-incompatibility response ('Comune', self-incompatible; and 'Monreal', a self-compatible mutation of 'Comune'). Transcriptome profiling was performed using the Affymetrix Citrus GeneChip representing up to 33,000 citrus transcripts. Among them, only 10 genes resulted over represented in 'Comune' stylar canals and 7 genes in 'Monreal' ones. The results of microarray hybridizations were validated using real time quantitative RT-PCR. Many of the differentially expressed genes are not functionally annotated in citrus or other plant species. The results suggest that the differential regulation of few specific transcripts is probably related to the breakdown of self-incompatibility in 'Monreal'.

Perez-Gago M.B.,Instituto Valenciano Of Investigaciones | Navarro M.L.,Instituto Valenciano Of Investigaciones | Del Rio M.A.,Instituto Valenciano Of Investigaciones
Acta Horticulturae | Year: 2010

'Ortanique' mandarins were coated with hydroxypropyl methylcellulose (HPMC)-beeswax (BW) composite coatings. Glycerol and fatty acid were added as plasticizer and emulsifier, respectively. The emulsion coatings had 4% total solid content and 40%BW content (dry basis). Stearic, palmitic or oleic acid were studied at two different BW: fatty acid ratios (2:1 and 5:1). After coating, the fruits were stored for 3 and 6 weeks at 5°C, followed by one additional week at 20°C. Another set of samples was also stored for 2 weeks at 20°C, simulating retail handling conditions. The coatings were effective reducing weight loss and maintaining texture of mandarins compared to the control. Coatings with oleic acid were more effective reducing weight loss than coatings with palmitic acid, and these ones more effective than those with stearic acid. However, oleic acid increased the gas barrier, ethanol level and off-flavor of coated mandarins in a greater extend that palmitic and stearic. Levels of internal CO2 were lower in coatings with a BW:fatty acid ratio 2:1 than in coatings with 5:1 ratio, which translated in lower ethanol level in juice. This could be due to the lower amount of HPMC in the 2:1 ratio-coatings, since hydrophilic materials, such as HPMC, are known to present low oxygen permeability. The results suggest the importance of controlling coating composition in order to extend shelf-life of citrus fruits with good quality.

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