Abstract

Onion (Allium cepa L.) is an economically important vegetable crop worldwide. However, various fungal diseases, including Fusarium basal rot (FBR), neck rot, and white rot, reduce onion production or bulb storage life. FBR caused by Fusarium species is among the most destructive onion diseases. In this study, we identified Fusarium species associated with FBR in Jeolla and Gyeongsang Provinces in South Korea and evaluated fungicides against the pathogens. Our morphological and molecular analyses showed that FBR in onions is associated with Fusarium commune, Fusarium oxysporum, and Fusarium proliferatum. We selected seven fungicides (fludioxonil, hexaconazole, mandestrobin, penthiopyrad, prochloraz-manganese, pydiflumetofen, and tebuconazole) and evaluated their inhibitory effects on mycelial growth of the pathogens at three different concentrations (0.01, 0.1, and 1 mg/mL). We found that prochloraz-manganese was highly effective, inhibiting 100% of the mycelial growth of the pathogens at all concentrations, followed by tebuconazole. Fludioxonil showed < 50% inhibition at 1 mg/mL for the tested isolates.

摘要

洋葱（Allium cepa L.）是世界范围内重要的经济蔬菜作物。然而，各种真菌病害，包括镰刀菌基腐病（FBR）、颈腐病和白腐病，会降低洋葱产量或球茎储藏寿命。由镰刀菌引起的 FBR是最具破坏性的洋葱病害之一。在这项研究中，我们鉴定了韩国全罗道和庆尚省与 FBR 相关的镰刀菌属物种，并评估了针对该病原体的杀菌剂。我们的形态学和分子分析表明，洋葱中的 FBR 与Fusarium commune、Fusarium oxysporum和Fusarium proliferatum相关。我们选择了七种杀菌剂（咯菌腈、己唑醇、曼地肟、吡噻菌胺、咪鲜胺锰、吡氟草芬和戊唑醇），并评估了它们在三种不同浓度（0.01、0.1和1 mg/mL）下对病原体菌丝生长的抑制作用。我们发现咪鲜胺锰非常有效，在所有浓度下都能 100% 抑制病原体的菌丝生长，其次是戊唑醇。咯菌腈在 1 mg/mL 浓度下对测试分离株的抑制率 < 50%。