First Report of Leaf Spot and Root Rot Caused by <i>Phoma betae</i> on <i>Beta vulgaris</i> subsp. <i>vulgaris</i> (Garden Beet Group) in Italy
Notice bibliographique
Résumé
In the winter of 2007 in Piedmont (northern Italy), symptoms of a previously unknown disease were observed on beet (Beta vulgaris L. subsp. vulgaris) (garden beet group) grown under a tunnel on several commercial farms near Cuneo. First symptoms appeared on 1-month-old plants, occurring as brown, round-to-oval spots as much as 2 cm in diameter with dark concentric rings near the perimeter. Small, dark pycnidia were present throughout the spots in concentric rings. Generally, older, lower leaves were affected more than the younger ones. Ten to fifteen percent of the plants were affected. Symptoms on the roots began near the crown as small, dark, sunken spots that became soft and water soaked. Eventually, spots on the roots turned dark brown to black and black lines separated diseased and healthy tissues. Older infected tissues were black, dry, shrunken, and spongy. Pycnidia were not observed on affected roots. From infected leaves and roots, a fungus was consistently isolated on potato dextrose agar (PDA) amended with 25 mg/l of streptomycin. The fungus was grown on PDA and maintained at 22°C (12 h of light, 12 h of dark). After 10 days, black pycnidia (130 to 328 [204] μm in diameter) developed, releasing abundant hyaline, elliptical, nonseptate conidia measuring 3.9 to 6.7 (5.1) × 2.4 to 5.9 (3.6) μm. On the basis of its morphological characteristics, the fungus was identified as a Phoma sp. (1). The internal transcribed spacer (ITS) region was amplified using primers ITS4/ITS6 (2) and sequenced. BLASTn analysis of the 557 bp obtained showed an E-value of 0.0 with Phoma betae. The nucleotide sequence has been assigned GenBank Accession No. EU003450. Pathogenicity tests were performed by spraying leaves of healthy 20-day-old potted B. vulgaris plants with a spore and mycelial suspension (1 × 10 6 spores or mycelial fragments per ml). Noninoculated plants sprayed only with water served as controls. Fifteen plants (three per pot) were used for each treatment. Plants were covered with plastic bags for 5 days after inoculation and kept in a growth chamber at 20°C. Symptoms previously described developed on leaves of all inoculated plants 5 days after inoculation, while control plants remained healthy. Later, pycnidia and conidia, with the same dimensions and characteristics previously described, were observed on the infected leaves. The fungus was consistently reisolated from the lesions of the inoculated plants. The pathogenicity test was carried out twice. P. betae on B. vulgaris var. cycla has been reported in Canada (3) as well as in other countries. The same pathogen was reported in Italy on sugar beet (2). References: (1) G. H. Boerema and G. J. Bollen. Persoonia 8:111, 1975. (2) A. Canova. Inf. Fitopatol. 16:207, 1966. (3) D. E L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (4) J. R. Howard et al. Diseases of Vegetable Crops in Canada. Canadian Phytopathological Society, 1994.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 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 tête enseignante, 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 ».