First Report of <i>Plum pox virus</i> Strain M Isolates in Apricot in Sicily, Italy
Notice bibliographique
Résumé
Sharka or plum pox disease is one of the most economically important virus diseases of stone fruits. Plum pox virus (PPV), the causal agent, is a member of the genus Potyvirus of the family Potyviridae transmitted by aphids in a non-persistent manner and by grafting. To date, nine PPV strains have been described on the basis of their biological, serological, and molecular properties: M and D are the most widespread and economically important strains, PPV-Rec and PPV-C have been reported mainly in Europe, PPV-EA confined to Egypt, PPV-T to Turkey, PPV-W from Canada, Ukraine, Latvia, and Russia, PPV-CR detected in Russia, and finally a putative PPV strain infecting plum in Albania described as the ancestor of the M. PPV-M is responsible for major epidemics in many Italian regions and despite phytosanitary measures, the infection rate increases each year. The D and Rec isolates are sporadically reported while PPV-C, once signaled in Apulia, has been successfully eradicated. Except for a report from the 1980s, which is no longer traceable, Sicily was considered free from the virus (2). In 2012, two new foci of sharka in a coastal area of Catania in Sicily were first reported by the national plant protection service to the European Commission (DG-SANCO). In spring 2013, plants of different varieties of apricot (Prunus armeniaca) and peach (P. persica) showing typical symptoms of flower color break, yellowing and leaf deformation, chlorotic spots or rings, and malformation on fruits were tested positive to PPV by DAS-ELISA using polyclonal antibodies. In order to characterize two isolates from apricot varieties (Carmen Top and Ninfa), total RNAs, extracted using the RNeasy Plant Mini Kit (Qiagen) from ELISA-positive samples, were analyzed by RT-PCR with primers P1/P2, targeting the 3'-terminal region of the coat protein (CP) gene (5) followed by RFLP analysis after digestion with Rsa1. Subsequently total RNAs were analyzed with the type-specific primers P1/PM and P1/PD (3), P3M/P4b and P3D/P4b amplifying the N-terminal region of the CP gene (1) and, finally, with primers mD5/mD3, mM5/mM3, and mD5/mM3, amplifying the region 3'NIb-5'CP, including the recombination site of Rec isolates (4). Only primer pairs P1/P2, P1/PM, P3M/P4b, and mM5/mM3 produced amplicons of the expected size (243, 198, 466, and 459 bp, respectively). The RFLP assay confirmed both isolates belonging to the M strain. Moreover, no reaction was obtained with primer pair mD5/mM3, excluding isolates belonging to Rec-type. Isolate characterization was completed by direct sequencing in both directions of the of P1/P2 and P3M/P4b amplicons obtained from apricot samples L9-1 (Carmen Top isolate) and 9-335 (Ninfa isolate). The P1/P2 sequences (KJ994235, KJ994237) showed 98% similarity with PPV-M or PPV-Rec isolates. The P3M/P4b sequences (KJ994236, KJ994238) confirmed that Sicilian isolates belong to the PPV-M strain showing 99% similarity with those already present in GenBank, thus ruling out the possibility of an infection with a PPV-Rec isolate. This outbreak of the Marcus strain of PPV in Sicily represents a high risk for the expanding production of stone fruit in southern Italy. An eradication plan was quickly activated by the regional phytosanitary service. References: (1) T. Candresse et al. Phytopathology 101:611, 2011. (2) EPPO. PQR-EPPO database on quarantine pests (available online). http://www.eppo.int , 2014. (3) A. Olmos et al. J. Virol. Methods 68:127, 1997. (4) Z. Subr et al. Acta Virol. 48:173, 2004. (5) T. Wetzel et al. J. Virol. Methods 33:355, 1991.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,001 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».