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Chabirand A.,ANSES Plant Health Laboratory | Jouen E.,University of Reunion Island | Pruvost O.,University of Reunion Island | Chiroleu F.,University of Reunion Island | And 17 more authors.
Plant Pathology | Year: 2014

Efficient control of Xanthomonas axonopodis pv. dieffenbachiae, the causal agent of anthurium bacterial blight, requires sensitive and reliable diagnostic tools. The European standard EN ISO 16140:2003 has been followed to compare a nested PCR assay (N-PCR) to a reference method (isolation and serological identification of bacterial colonies) and to other alternative serological detection methods. The evaluation was performed in two steps: a comparative study and a collaborative study involving 15 European laboratories. Although inclusivity was maximal (100%) for all methods, a maximal exclusivity was obtained only with N-PCR followed by an enzymatic restriction digestion of the amplicons. Exclusivity indices of 90·6, 88·7 and 47·2% were found for indirect ELISA, immunofluorescence and double antibody sandwich ELISA, respectively. An exclusivity of 92·5% was obtained with the reference method, further increased to 100% if pathogenicity tests were performed as a supplemental assay. The best level of sensitivity (relative detection level) was obtained with the reference method followed by the N-PCR assay. The N-PCR performance in terms of relative accuracy, accordance and concordance was very similar to that of the reference method. Moreover, N-PCR had undeniable advantages compared to the reference method (less labour-intensive and less time-consuming). In addition, post-test probabilities of infection were calculated to select the most appropriate detection scheme related to the prevalence of the pathogen. The N-PCR assay has since been included in a revised version of the EPPO detection protocol. © 2013 British Society for Plant Pathology. Source

NunEZ Vazquez L.,Servicio de Sanidad Forestall | Olmo D.,Laboratorio Of Sanidad Vegetal | Canyelles X.,Societat dHistoria Natural de les Illes Balears | Riba J.M.,Consultor
Bolleti de la Societat d'Historia Natural de les Balears | Year: 2015

Is reported for the first time, with specifics on location in Majorca (Balearic Islands) from Australia to cerambycid Phoracantha semipunctata (Fabricius, 1775) (Col.: Cerambycidae). Source

Hernandez-Hernandez J.,ICIA | Espino A.,Laboratorio Of Sanidad Vegetal | Rodriguez-Rodriguez J.M.,Laboratorio Of Fitopatologia | Perez-Sierra A.,Polytechnic University of Valencia | And 3 more authors.
Phytopathologia Mediterranea | Year: 2010

Between 2006 and 2007, palm trees growing in both gardens and public parks and natural palm groves in the Canary Islands (Spain), and showing symptoms of wilt and dieback, were surveyed. Isolates were recovered from affected tissues of the crowns, leaves and vascular fragments on potato dextrose agar (PDA). After incubation, the Fusarium spp. colonies recovered were single-spored. They were transferred to PDA and Spezieller Nährstoffarmer Agar (SNA) for morphological identification. Identification of Fusarium oxysporum f. sp. canar- iensis was confirmed by PCR with the specific primers HK66 and HK67, which amplified a fragment of 567 bp. Fusarium wilt caused by F. oxysporum f. sp. canariensis was found on 54 Phoenix canariensis trees growing on four islands: Gran Canaria, Fuerteventura, La Palma and Tenerife. F. proliferatum occurred on fifteen palms (10 P. canariensis, 1 P. dactylifera, 3 Roystonea regia and 1 Veitchia joannis) located in Gran Canaria, Fuerteventura and Tenerife. Both these Fusarium species were found only in diseased palms from gardens and public parks, but not in natural palm groves. The results show that Fusarium wilt of P. canariensis is common in the Canary Islands and for the first time report F. proliferatum affecting different palm species in those islands. Source

Fiallo-Olive E.,University of Malaga | Espino A.I.,Laboratorio Of Sanidad Vegetal | Botella-Guillen M.,Laboratorio Of Sanidad Vegetal | Gomez-Gonzalez E.,Laboratorio Of Sanidad Vegetal | And 2 more authors.
Plant Disease | Year: 2014

In March 2013, symptoms of mild leaf curling, mosaic, and interveinal yellowing were observed in tobacco (Nicotiana tabacum) plants grown in a row surrounding the exterior of a greenhouse containing a tomato crop in Guía de Isora, Tenerife (Canary Islands, Spain). The tobacco plants were found lightly infested by the whitefly (Hemiptera: Aleyrodidae) Bemisia tabaci. The greenhouses in this area are devoted to the commercial production of tomato. The farmers grow some tobacco plants inside and outside of them as a reservoir of parasitoids and depredators of B. tabaci. This insect is the natural vector of the main viruses severely affecting tomato in the Canary Islands, the begomovirus Tomato yellow leaf curl virus and the crinivirus Tomato chlorosis virus (ToCV). ToCV was detected in Spain in 1997 (2) and has become established in most of the coastal provinces of eastern and southern continental Spain and in the Canary Islands. Approximately 50% of the tomato plants grown inside the greenhouse close to the tobacco plants showed typical ToCV symptoms, and infection by this virus was confirmed in the seven plants tested by reverse transcription (RT)-PCR using specific coat protein gene (CP) primers (see below). Total RNA was extracted with TRIzol Reagent (Invitrogen) from leaves of five tobacco plants showing the symptoms mentioned above and analyzed by dot-blot hybridization using digoxigenin-labeled RNA probes to the CP gene of ToCV. Positive signal was obtained for all five plants. RT-PCR reactions were performed with specific primers for the detection of ToCV, MA380(+) (5′-GTGAGACCCCGATGACAGAT-3′) and MA381(-) (5′-TACAGTTCCTTGCCCTCGTT-3′), specific to the CP gene (ToCV RNA 2) (3), and MA396(+) (5′-TGGTCGAACAGTTTGAGAGC-3′) and MA397(-) (5′-TGAACTCGAATTGGGACAGA-3′), specific to the RNA-dependent RNA polymerase (RdRp) gene (ToCV RNA 1) (1). DNA fragments of the expected size (436 and 763 bp, respectively) were obtained, thus supporting the presence of ToCV in the symptomatic samples. The amplified product of the RdRp gene fragment from one sample was directly sequenced (Macrogen Inc., South Korea) and resulted closely related to ToCV isolates from Sudan (GenBank Accession No. JN411686, 99.6% nt identity) and Spain (DQ983480, 99.4% nt identity), thereby confirming the infection by this virus. Partial sequence of the ToCV isolate from tobacco was deposited in GenBank under accession no. KJ175084. In addition, all five plants resulted positive when analyzed by ELISA for Tomato spotted wilt virus and Potato virus Y and by PCR for Tomato yellow leaf curl virus (data not shown), all three viruses reported to infect naturally tobacco. Although tobacco has been reported as an experimental host of ToCV (4), to our knowledge, this is the first report of this species as a natural host of this virus. The finding of ToCV infecting tobacco raises the question of whether this virus could emerge as a pathogen of this crop and questions the use that farmers make of tobacco as reservoirs of natural enemies for whitefly control in tomato. © 2014 The American Phytopathological Society. Source

Berbegal M.,Polytechnic University of Valencia | Landeras E.,Laboratorio Of Sanidad Vegetal | Sanchez D.,Laboratorio Of Sanidad Vegetal | Abad-Campos P.,Polytechnic University of Valencia | And 2 more authors.
Forest Pathology | Year: 2015

In this study, the effects of hot water (HWT), hydrogen peroxide and fungicides on the incidence of Fusarium circinatum on artificially inoculated Pinus radiata seeds were evaluated. Fifteen commercial fungicide formulations were screened in vitro for inhibitory activity on mycelial growth and conidial germination of F. circinatum. With half-maximal effective concentration (EC50) lower than 0.5 ppm, fluazinam, imazalil and tebuconazole were the most effective fungicides on mycelial growth, while captan, mancozeb or pyraclostrobin were the most effective (EC50 < 0.3 ppm) on conidial germination. Based on the results obtained, imazalil, fluazinam, mancozeb and pyraclostrobin were selected for further testing. The effects of HWT, hydrogen peroxide and fungicide treatments on seed emergence and the incidence of F. circinatum were assessed. Seed treatments with fungicides prior to sowing were less effective and inconsistent in reducing the incidence of F. circinatum on seedlings. In contrast, hot water and hydrogen peroxide treatments significantly reduced F. circinatum contamination on P. radiata seeds with an overall disease incidence lower than 0.8% on seedlings. Furthermore, subsequent application of fungicides on seedlings did not improve the effectiveness of HWT. These results, therefore, suggest that hot water is a better alternative to hydrogen peroxide and fungicides as Pinus seed treatment against F. circinatum and could easily be implemented as standard in commercial nurseries to control the spread of the pitch canker disease. © 2015 Blackwell Verlag GmbH. Source

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