First Report of Leaf Spot and Stem Blight on Blueberry (<i>Vaccinium corymbosum</i> ‘Bluerain’) Caused by <i>Calonectria pseudoreteaudii</i> in China
Notice bibliographique
Résumé
Blueberry has high nutritional value and is one of the five healthy fruits. In 2018, leaf spots and stem blights were observed on Vaccinium corymbosum cv. Bluerain in Guangzhou, Guangdong Province, China. Up to 80% of the plants were affected. Initial symptoms of affected leaves were red-brown, irregular, small spots, which gradually coalesced and formed larger irregular necrotic patches. The affected stems showed red-brown and irregular large lesions. Diseased tissues were surface sterilized with 75% alcohol for 15 s, followed by 2.5% NaClO for 30 s, and rinsing three times in sterile distilled water, placed on potato dextrose agar (PDA) and incubated at 25 C. Representative strains, ZHKUCC 21-0021 from diseased leaves and ZHKUCC 21-0073 from diseased stems, were selected for further studies. Colonies grew slowly at 25 C on malt extract agar (MEA) (average 5.68 mm/d), producing white aerial mycelium and red-brown color on the underside after 7 days. Macroconidiophores were hyaline, smooth, consisting of a stipe bearing fertile branches, and a stipe extension terminating in a vesicle. Each terminal branch produced 2-4 phialides, 8-13 × 3-6 μm, reniform or doliiform; Stipe extensions were septate, terminating in a narrowly clavate vesicle, 2-6 μm. Macroconidia were hyaline, straight cylindrical, round at both ends, 83-100 × 7-11 μm (average = 94 × 8 μm; n = 50), with 5 septa. These morphological characteristics were similar to the description of Calonectria pseudoreteaudii (Lombard et al., 2010). The partial calmodulin (cmdA), beta-tubulin (β-tubulin), and translation elongation factor 1-alpha (tef1-α) genes of the two isolates were respectively amplified using primers CAL-228F/CAL-737R (Carbone et al., 1999), EF1-728F/EF2 and T1/CYLTUB1R (Lombard et al., 2015), and sequences were deposited in GenBank (cmdA: MZ516854 and MZ516855; β-tubulin: MZ516858 and MZ516859; tef1-α: MZ516856 and MZ516857). BLAST analysis of three gene sequences showed 100% similarity to those of C. pseudoreteaudii. In the maximum likelihood (ML) tree of the concatenated sequences of the three genes, the two isolates from this study were clustered with C. pseudoreteaudii with 100% bootstrap support. Five-mm-diameter hyphal plugs of two representative isolates grown on PDA for five days were used in the pathogenicity test. Leaves were inoculated with ZHKUCC 21-0021, and stems were inoculated with ZHKUCC 21-0073 with five replicates. As controls, sterile PDA plugs were used. All inoculated plants were maintained at 25 C . After 7 days, inoculated leaves and stems developed symptoms similar to field samples, whereas the control plants remained asymptomatic. The pathogen was reisolated from inoculated plants and confirmed to be C. pseudoreteaudii by morphological characteristics. Five Calonectria species (C. canadensis, C. colhounii, C. ilicicola, C. kyotensis and C. pyrochroa), have been reported associated with blueberry (Farr and Rossman, 2022; Fei et al, 2017). Calonectria canadensis and C. ilicicola have been reported to cause stem blight and stem rot in Vaccinium spp. in China (Fei et al, 2017 and 2018). Calonectria colhounii has been reported to cause stem blight in V. angustifolium and V. corymbosum in the United States (Sadowsky et al, 2011). However, this is the first report of C. pseudoreteaudii causing leaf spot and stem blight on Vaccinium spp. worldwide. These results will provide a foundation for future research on prevention and control of this disease.
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 ».