Fire blight risk assessment during bloom in an experimental orchard using BIS (Billing's Integrated System)     

Pascal Lecomte  Jean-Pierre Paulin  Eve Billing 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(7):667-675

The value of BIS for blossom blight risk assessment was studied from data collected in an experimental orchard in south-west France. Trees observed included mature commercial pear and apple trees and some young trees in experimental plots. There was a weather station in the orchard and beehives were present. Field records included flowering times of the pear and apple cultivars studied (mostly Passe-Crassane and Beurré Hardy, Royal Gala and Golden Delicious) and dates when blossom blight was first seen on each cultivar. Between 1980 and 1991, records of blight were available for 25 cases. In most cases, one or more infection risk (IR) days, as defined for BIS, could be found during bloom. DD13 mean sums (sums of degree days above a mean temperature of 13 °C) gave good guidance on times when early signs of blossom blight were present in 14 cases. There was only a slight divergence from BIS guides in a further five cases. Possible reasons for divergence and for non-fit in the remaining six cases are discussed. It is concluded from this study that BIS should give useful guidance on optimal times for protective spray applications and for timing of searches for signs of early blossom blight in south-west of France. Graphical presentations of data provide additional information.  相似文献   

Molecular assays for detection of falcon adenovirus.   总被引：1，自引：0，他引：1  

Mark Schrenzel  Eric Snook  Pascal Gagneux 《Journal of veterinary diagnostic investigation》2007,19(5):479-485

Falcon adenovirus is a newly recognized member of the family Aviadenoviridae and includes 2 closely related strains that are pathogenic to several species of falcons. Peregrine falcons appear to be one of the primary reservoirs, but recent outbreaks suggest that other carrier species probably exist. To allow screening of captive birds for virus shedding and investigations of disease outbreaks, conventional and real-time, quantitative polymerase chain reaction (PCR) assays and an in situ hybridization technique were developed. The diagnostic protocols were used on tissue and fecal samples from 7 species or subspecies of falcons infected with adenovirus as well as adenoviruses from other birds and mammals. The assays were specific for falcon adenovirus and detected both strains of virus in fecal samples from living animals or frozen and formalin-fixed, paraffinized tissues. Together with established serologic tests for falcon adenovirus, these molecular assays are valuable tools for management and conservation of falcons in captivity and the wild.  相似文献   

Attempts to eliminate <Emphasis Type="Italic">Candidatus</Emphasis> phytoplasma phoenicium from infected Lebanese almond varieties by tissue culture techniques combined or not with thermotherapy     

Lamis?ChalakEmail author  Ahmad?Elbitar  Reine?Rizk  Elia?Choueiri  Pascal?Salar  Joseph?M.?Bové 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(1):85-89

Elimination of Candidatus phytoplasma phoenicium from two infected Lebanese varieties of almond by using different tissue culture techniques is reported. Except for the oxytetracycline therapy which totally inhibited the development of explants, stem cutting cultures associated with thermotherapy, shoot tip cultures associated or not with thermotherapy, and shoot tip micrografting were all suitable, either for shoot regeneration or for elimination of phytoplasma from the two varieties. However, stem cutting culture coupled with thermotherapy seemed to be the most effective for regeneration of phytoplasma-free plantlets.  相似文献   

Polyvalent degenerate oligonucleotides reverse transcription-polymerase chain reaction: a polyvalent detection and characterization tool for trichoviruses, capilloviruses, and foveaviruses     

Foissac X  Svanella-Dumas L  Gentit P  Dulucq MJ  Marais A  Candresse T 《Phytopathology》2005,95(6):617-625

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A mathematical model of the effects of chronic carriers on the within-herd spread of contagious bovine pleuropneumonia in an African mixed crop-livestock system     

Lesnoff M  Laval G  Bonnet P  Chalvet-Monfray K  Lancelot R  Thiaucourt F 《Preventive veterinary medicine》2004,62(2):101-117

Contagious bovine pleuropneumonia (CBPP) is a respiratory disease of cattle; CBPP is caused by Mycoplasma mycoides subsp. mycoides small colony. CBPP is a major cause for concern for African countries (because of mortality, animal-production losses and cost of control). The clinical form of the disease is the more infectious (contagion occurs essentially through coughing). However, chronic lung lesions with viable mycoplasmas can persist in recovering cattle. Animals presenting these lesions might have a time-delimitated infectious phase. Such carriers are suspected to generate field outbreaks (although this hypothesis remains debated). We investigated the potential quantitative effects of these chronic carriers on the within-herd CBPP spread. Data were collected during a longitudinal field herd survey in a mixed crop-livestock system in the Ethiopian highlands. Two stochastic Markov-chain models' outputs (seroconversion dynamics, basic reproduction ratio R0, cumulative clinical incidence and risk of herd infection) were compared given different hypotheses on the carrier infectiousness. The late seroconversions observed in the field data were fitted correctly only for the highest carrier infectiousness we considered (mean chronic duration of 1 year and carriers 50-times less infectious than clinical cases). Although sensitivities (in terms of disease impact in the herd) were in general negligible when the carrier infectiousness was low (e.g. when carriers were assumed to be 1000-times less infectious than clinical cases), they rapidly became important when the infectiousness increased.  相似文献   

Whole body barometric plethysmography: a screening method to investigate airway reactivity and acute lung injuries in freely moving pigs     

Halloy DJ  Kirschvink NA  Vincke GL  Hamoir JN  Delvaux FH  Gustin PG 《Veterinary journal (London, England : 1997)》2004,168(3):276-284

The aim of this work was to investigate whether the Penh index, measured using whole body barometric plethysmography, can be used as a screening parameter to evaluate the airway reactivity and the intensity of the pulmonary response to endotoxins. Penh was firstly recorded in non-sedated freely moving piglets exposed (1) to a nebulized acetylcholine (Ach) pre-treated or not with clenbuterol, or (2) to endotoxin challenge. To measure Penh simultaneously with total pulmonary resistance (R(L)), dynamic compliance (C(dyn)) and intrapleural pressure changes (Max Delta Ppl), an oesophageal balloon catheter technique was used and the piglets were anaesthetised. The recordings were performed during (1) an intravenous metacholine (Mch) challenge and (2) in endotoxin-exposed animals. In freely moving animals, Ach induced a significant dose-dependent increase in Penh, which was significantly blocked by clenbuterol. Endotoxin instillation also resulted in a significant rise in Penh while the corresponding response measured under anaesthesia was significantly and positively correlated with R(L) and Max Delta Ppl. Similar results were obtained during Mch challenge but the Penh was negatively correlated with C(dyn). We conclude that Penh could be used in freely moving piglets as a screening index for airway reactivity and pulmonary functional changes in cholinergic and endotoxin challenges.  相似文献   

Characterization of a New Nepovirus Infecting Apricot in Southeastern France: Apricot Latent Ringspot Virus     

Pascal Gentit  René-Pierre Delbos  Thierry Candresse  Jean Dunez 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(5):485-494

A pathogen was transmitted from apricot trees showing symptoms of viral infection to GF305 peach seedlings which reacted by stunting, shortened internodes and chlorotic mottling. The agent was transmitted to cherry, apricot, peach and plum by grafting and to several herbaceous hosts by mechanical inoculation. Isometric nepovirus-like particles of 30–31 nm diameter extracted from infected Chenopodium quinoa sedimented as two peaks in sucrose gradients. These particles contained two single stranded RNAs of approximately 5.9 and 7.9 kb, and a single coat protein subunit of 53.7 kDa. No cross-reactions were observed with a number of nepoviruses infecting fruit trees. Inoculation of purified particles to herbaceous or woody hosts reproduced the same symptoms caused by the original isolate. Sequencing of a 2.2 kbp cDNA clone covering the 3 end of the small genomic RNA identified an open reading frame encoding a 317 aa N-truncated protein exhibiting significant similarities with the coat protein of nepoviruses. The 1257 nt long 3 non-coding region showed up to about 65% homology to the equivalent region of members of the subgroup C of nepoviruses. The properties of this pathogen do not match those of any previously described nepovirus. It should therefore be considered as a new member of the subgroup C of nepoviruses, for which the name of Apricot latent ringspot virus (ALRSV) is proposed.The nucleotide sequence reported in this work has been deposited in the EMBL databank under the accession number AJ278875.  相似文献   

Usefulness of single copy genes containing introns in Phytophthora for the development of detection tools for the regulated species P. ramorum and P. fragariae     

Renaud Ioos  Lise Laugustin  Nathalie Schenck  Sylvie Rose  Claude Husson  Pascal Frey 《European journal of plant pathology / European Foundation for Plant Pathology》2006,116(2):171-176

Introns are generally highly polymorphic regions within genes and were proven to be of great interest for discriminating among phylogenetically-close Phytophthora species. Phytophthora ramorum and P. fragariae are considered as quarantine pathogens by the European Union and accurate detection tools are therefore necessary for their monitoring. From introns located in different single copy genes (GPA1, RAS-like, and TRP1), we developed a series of PCR primers specific to P. ramorum and P. fragariae. The specificity of these primers was successfully checked with a wide collection of Phytophthora isolates and a protocol was developed to detect both pathogens directly in infected plant tissues. These genes should be of particular interest for the development of additional species-specific detection tools within the Phytophthora genus.  相似文献   

Glossopharyngeal Insufflation and Breath-Hold Diving: The More,the Worse?     

Alain Boussuges  Olivier Gavarry  Jacques Bessereau  Mathieu Coulange  Morgan Bourc’his  Pascal Rossi 《The Forestry Chronicle》2014,25(4):466-471

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Misconduct annotations     

Pascal CB 《Science (New York, N.Y.)》1996,274(5290):1066b-1067b

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