Cosseboom Scott David, Hu Mengjun
University of Maryland at College Park, 1068, Plant Science and Landscape Architecture, College Park, Maryland, United States;
University of Maryland at College Park, 1068, Department of Plant Science and Landscape Architecture, College Park, Maryland, United States;
Plant Dis. 2021 Mar 9. doi: 10.1094/PDIS-03-20-0487-RE.
From 2014 to 2019, 249 isolates of Botrytis sp. were collected from blackberry, black raspberry, grape, red raspberry, and strawberry showing gray mold symptoms. All isolates were phylogenetically characterized as Botrytis cinerea. A mycelial growth assay determined the following overall frequencies of resistance to fungicides: 92% to pyraclostrobin, 86% to cyprodinil, 71% to thiophanate-methyl, 48% to fenhexamid, 47% to iprodione, 26% to boscalid, 11% to fludioxonil, 8% to penthiopyrad, 7% to benzovindiflupyr, 4% to pydiflumetofen , and 4% to isofetamid. Isolates collected from blackberry, red raspberry, and strawberry had a higher median chemical class resistance value compared to isolates from black raspberry and grape. Resistance conferring mutations were found in a selection of isolates characterized as resistant to thiophanate-methyl, iprodione, pyraclostrobin, fenhexamid, and boscalid including E198A in β-tubulin; I365N/S, Q369P, and N373S in bos1; G143A in cytb; P238S, N369D, and F412I/S in erg27; and P225F and H272R/Y in sdhB, respectively. Also, multiple drug resistance phenotypes MDR1 and MDR1h were identified by analyzing fludioxonil sensitivity and mrr1 sequences. MDR1 and MDR1h isolates had multiple amino acid variations and two insertions in mrr1 that resembled the group S genotype . A detached grape assay confirmed that the aforementioned mutations in isolates from different small fruit crops resulted in field-relevant resistance. An additional in-vitro assay found that EC50 values of B. cinerea isolates to pydiflumetofen and inpyrfluxam averaged 0.4 and 1.0, 0.8 and 0.7, 149.8 and 23.2, 0.9 and 0.9, and 38.8 and 48.8 µg/ml for the wild-type, H272R, H272Y, N230I, and P225F genotypes, respectively. These results revealed widespread fungicide resistance in B. cinerea from Mid-Atlantic small fruit fields, highlighting the need for resistance management alternatives.
2014年至2019年，从表现出灰霉病症状的黑莓、黑树莓、葡萄、红树莓和草莓中收集了249株葡萄孢属菌株。所有分离株在系统发育上均被鉴定为灰葡萄孢。菌丝生长试验确定了对杀菌剂的以下总体抗性频率：对吡唑醚菌酯为92%，对嘧菌环胺为86%，对甲基硫菌灵为71%，对苯酰菌胺为48%，对异菌脲为47%，对啶酰菌胺为26%，对咯菌腈为11%，对戊唑嘧菌酯为8%，对苄呋菊酯为7%，对氟吡菌酰胺为4%，对异噻菌胺为4%。与从黑树莓和葡萄中分离的菌株相比，从黑莓、红树莓和草莓中分离的菌株具有更高的化学类别抗性中值。在一些被鉴定为对甲基硫菌灵、异菌脲、吡唑醚菌酯、苯酰菌胺和啶酰菌胺耐药的分离株中发现了耐药性赋予突变，包括β-微管蛋白中的E198A；bos1中的I365N/S、Q369P和N373S；cytb中的G143A；erg27中的P238S、N369D和F412I/S；以及sdhB中的P225F和H272R/Y。此外，通过分析咯菌腈敏感性和mrr1序列鉴定了多药耐药表型MDR1和MDR1h。MDR1和MDR1h分离株在mrr1中有多个氨基酸变异和两个插入，类似于S组基因型。离体葡萄试验证实，来自不同小果作物的分离株中的上述突变导致了与田间相关的抗性。另一项体外试验发现，灰葡萄孢分离株对氟吡菌酰胺和吲唑磺菌胺的EC50值，野生型、H272R、H272Y、N230I和P225F基因型分别平均为0.4和1.0、0.8和0.7、149.8和23.2、0.9和0.9、38.8和48.8μg/ml。这些结果揭示了来自大西洋中部小果田的灰葡萄孢中广泛存在的杀菌剂抗性，突出了对抗性管理替代方案的需求。
