Abstract The objectives of this work were to investigate the Botrytis species that cause gray mold in strawberries in Parana and to study their sensitivity to fungicides: procymidone (P), iprodione (I), boscalid (B), thiophanate-methyl (T), fluazinam (F), azoxystrobin (A) and difenoconazole (D). The identification of 150 isolates of Botrytis sp. was carried out by amplifying the DNA by PCR using specific primers. The sensitivity to fungicides was determined by in vitro assays with discriminatory doses and EC50 (effective concentration to inhibit 50% of the growth of the fungus), molecular characterization of mutations and ex vivo assays for disease control efficacy. Thirty phenotypes were selected from combinations (S- sensitive and R- resistant) for the EC50 studies. Molecular characterization was performed using specific primers for mutations in the cyt b, bos1 and β-tubulin genes to confirm the resistance genotype. Tests were carried out with fruit treated with the fungicides (P), (B), (F) and (A) x the different phenotypes. All isolates were confirmed as Botrytis cinerea. Forty-one isolates were classified as fungicide sensitive phenotypes and of these, six isolates showed resistance to all seven tested fungicides. The percentage of isolates resistant to the fungicides azoxystrobin, boscalid, difenoconazole, fluazinam, iprodione and procymidone, was 90.0; 45.3; 33.3; 32,7; 43.3 and 44.0 % respectively. A total of 94.6% isolates were classified as highly resistant to thiophanate-methyl. The EC50 for the fungicides procymidone, fluazinam and boscalid ranged from less than 0.1 to greater than 100 μg/ml. For azoxystrobin, most isolates had an EC50 greater than 100 μg/ml. Isolates with more than one mutation for different fungicides were found. For the assay in fruits with infections from the field, only the fungicide fluazinam differed from the control treatment, showing lower final incidence of 33.3% and control efficiency of 55.6%. For the assay with inoculated fruits, the fungicide fluazinam best controlled the disease for the three isolates presenting an average final incidence of 33.3% and an average control efficiency of 61.9%. Therefore, disease management in the state of Parana should be reviewed in terms of registering new fungicides to gray mold and the use of integrated management measures to reduce the reliance on fungicides

中文翻译：

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巴西巴拉那州草莓中的灰霉病是由灰葡萄孢菌引起的，其分离株表现出对多种杀菌剂的抗性

摘要 这项工作的目的是调查导致巴拉那州草莓灰霉病的 Botrytis 物种，并研究它们对杀菌剂的敏感性：腐霉利 (P)、异菌脲 (I)、啶酰菌胺 (B)、甲基硫菌灵 (T)、氟啶胺 (F)、嘧菌酯 (A) 和苯醚甲环唑 (D)。Botrytis sp. 150 株分离株的鉴定 通过使用特异性引物通过PCR扩增DNA来进行。对杀真菌剂的敏感性是通过体外试验确定的，其中有区别剂量和 EC50（抑制 50% 真菌生长的有效浓度）、突变的分子特征和疾病控制功效的离体试验。从 EC50 研究的组合（S 敏感性和 R 抗性）中选择了 30 种表型。使用针对 cyt b、bos1 和 β-微管蛋白基因突变的特异性引物进行分子表征，以确认抗性基因型。对用杀菌剂 (P)、(B)、(F) 和 (A) x 不同表型处理的水果进行测试。所有分离株均被确认为灰葡萄孢菌。41 个分离株被归类为对杀菌剂敏感的表型，其中 6 个分离株对所有七种测试杀菌剂均表现出抗性。对嘧菌酯、啶酰菌胺、苯醚甲环唑、氟啶胺、异菌脲和腐霉利等杀菌剂耐药的菌株百分比为90.0；45.3; 33.3; 32,7; 分别为 43.3% 和 44.0%。共有 94.6% 的分离株被归类为对甲基硫菌灵高度耐药。杀真菌剂腐霉利、氟啶胺和啶酰菌胺的 EC50 范围从小于 0.1 到大于 100 μg/ml。对于嘧菌酯，大多数分离株的 EC50 大于 100 μg/ml。发现了对不同杀菌剂具有不止一种突变的分离株。对于田间感染水果的测定，只有杀菌剂氟啶胺与对照处理不同，最终发生率较低，为 33.3%，防治效率为 55.6%。对于接种水果的试验，杀菌剂氟啶胺对三种分离株的病害控制效果最好，平均最终发生率为 33.3%，平均控制效率为 61.9%。因此，巴拉那州的病害管理应在注册新的灰霉病杀菌剂和使用综合管理措施以减少对杀菌剂的依赖方面进行审查。发现了针对不同杀菌剂具有不止一种突变的分离株。对于田间感染水果的测定，只有杀菌剂氟啶胺与对照处理不同，最终发生率较低，为 33.3%，防治效率为 55.6%。对于接种水果的试验，杀菌剂氟啶胺对三种分离株的病害控制效果最好，平均最终发生率为 33.3%，平均控制效率为 61.9%。因此，巴拉那州的病害管理应在注册新的灰霉病杀菌剂和使用综合管理措施以减少对杀菌剂的依赖方面进行审查。发现了针对不同杀菌剂具有不止一种突变的分离株。对于田间感染水果的测定，只有杀菌剂氟啶胺与对照处理不同，最终发生率较低，为 33.3%，防治效率为 55.6%。对于接种水果的试验，杀菌剂氟啶胺对三种分离株的病害控制效果最好，平均最终发生率为 33.3%，平均控制效率为 61.9%。因此，巴拉那州的病害管理应在注册新的灰霉病杀菌剂和使用综合管理措施以减少对杀菌剂的依赖方面进行审查。3%，控制效率55.6%。对于接种水果的试验，杀菌剂氟啶胺对三种分离株的病害控制效果最好，平均最终发生率为 33.3%，平均控制效率为 61.9%。因此，巴拉那州的病害管理应在注册新的灰霉病杀菌剂和使用综合管理措施以减少对杀菌剂的依赖方面进行审查。3%，控制效率55.6%。对于接种水果的试验，杀菌剂氟啶胺对三种分离株的病害控制效果最好，平均最终发生率为 33.3%，平均控制效率为 61.9%。因此，巴拉那州的病害管理应在注册新的灰霉病杀菌剂和使用综合管理措施以减少对杀菌剂的依赖方面进行审查。