Chatzidimopoulos Michael, Zambounis Antonios, Lioliopoulou Fenia, Vellios Evangelos
Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, 38446 N. Ionia, 38221 Volos, Greece.
Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization 'ELGO DIMITRA', 57001 Thessaloniki, Greece.
Microorganisms. 2022 Nov 28;10(12):2354. doi: 10.3390/microorganisms10122354.
The excessive use of fungicides against , the causal agent of apple scab, has led to the emergence of resistant populations to multiple fungicides over the years. In Greece, there is no available information on fungicide resistance, despite the fact that control failures have been reported on certain areas. An amount of 418 single-spore isolates were collected from three major apple production areas and tested for their sensitivity to eight commonly used fungicides from unrelated chemical groups. The isolates were tested on malt extract agar media enriched with the discriminatory dose of each fungicide using the point inoculation method. To define the discriminatory dose for assessing the levels of resistance, EC values on both spore germination and mycelial growth assays were previously determined. Isolates exhibiting high resistance to trifloxystrobin (92% in total) and difenoconazole (3%); and moderate resistance to cyprodinil (75%), dodine (28%), difenoconazole (36%), boscalid (5%), and fludioxonil (7%) were found for the first time in Greece. A small percentage of the isolates were also found less sensitive to captan (8%) and dithianon (6%). Two isolates showed various levels of resistance to all eight fungicides. Despite the occurrence of strains with multiple resistances to many fungicides, we concluded that this practical resistance in the field arose mainly due to the poor control of apple scab with trifloxystrobin and difenoconazole.
多年来，针对苹果黑星病病原菌过度使用杀菌剂已导致出现了对多种杀菌剂具有抗性的种群。在希腊，尽管某些地区已报告防治失败，但尚无关于杀菌剂抗性的可用信息。从三个主要苹果产区收集了418个单孢分离株，并检测了它们对来自不相关化学组的八种常用杀菌剂的敏感性。使用点接种法，在添加了每种杀菌剂鉴别剂量的麦芽提取物琼脂培养基上对分离株进行检测。为确定用于评估抗性水平的鉴别剂量，之前已在孢子萌发和菌丝体生长试验中测定了EC值。在希腊首次发现了对肟菌酯（总计92%）和苯醚甲环唑（3%）表现出高抗性；对嘧菌环胺（75%）、多果定（28%）、苯醚甲环唑（36%）、啶酰菌胺（5%）和咯菌腈（7%）表现出中等抗性的分离株。还发现一小部分分离株对克菌丹（8%）和二噻农（6%）不太敏感。有两个分离株对所有八种杀菌剂表现出不同程度的抗性。尽管出现了对多种杀菌剂具有多重抗性的菌株，但我们得出结论，田间的这种实际抗性主要是由于使用肟菌酯和苯醚甲环唑对苹果黑星病防治不力所致。
