Amiri A, Heath S M, Peres N A
University of Florida, Gulf Coast Research and Education Center, Wimauma, FL 33598.
Plant Dis. 2013 Mar;97(3):393-401. doi: 10.1094/PDIS-08-12-0748-RE.
Chemical control has always been essential for the management of gray mold, caused by Botrytis cinerea, to ensure sustainable strawberry production. However, lack of knowledge about actual resistance development may have disastrous consequences and lead to severe epidemics such as the one that affected several strawberry fields in 2012 in Florida. In this study, we tested 392 isolates collected from Florida strawberry fields between 2010 and 2012 for their sensitivity to boscalid (Bosc), a succinate dehydrogenase inhibitor (SdhI); pyraclostrobin, a quinone outside inhibitor (QoI); boscalid + pyraclostrobin (Pristine); fenhexamid, a hydroxyanilide (Hyd); pyrimethanil and cyprodinil, anilinopyrimidines; fludioxonil, a phenylpyrrole; and fludioxonil + cyprodinil (Switch). The respective resistance frequencies for boscalid, pyraclostrobin, Pristine, fenhexamid, cyprodinil, and pyrimethanil were 85.4, 86.5, 86.0, 44.4, 52.7, and 59.5%. Overall, 17.8 and 19.8% of isolates showed reduced sensitivity to fludioxonil and Switch, respectively. All fungicides sprayed preventively on detached strawberry fruit failed to control isolates with high levels of resistance to each fungicide except for fludioxonil and Switch. Four phenotypes with multifungicide resistance (MFR) were detected in B. cinerea populations from Florida. Isolates resistant to one fungicide (FR1), two (MFR2), three (MFR3), and four (MFR4) fungicides from different chemical groups represented 5.9, 28.6, 41.8, and 23.7% of the total resistant population, respectively. The MFR3 isolates were predominant and contained two subpopulations, the Bosc-QoI-AP isolates (56.5%) and the Bosc-QoI-Hyd isolates (40.6%). In addition to reporting on very highly resistant populations to boscalid and QoI fungicides, we show evidence for a widespread multifungicide resistance to B. cinerea that warrants immediate implementation of novel management strategies to impede the development of more resistant populations.
化学防治对于由灰葡萄孢引起的灰霉病的管理一直至关重要，以确保草莓的可持续生产。然而，对实际抗药性发展缺乏了解可能会带来灾难性后果，并导致严重的病害流行，比如2012年在佛罗里达州影响多个草莓田的那次。在本研究中，我们测试了2010年至2012年间从佛罗里达州草莓田收集的392个分离株对以下药剂的敏感性：啶酰菌胺（Bosc），一种琥珀酸脱氢酶抑制剂（SdhI）；吡唑醚菌酯，一种醌外抑制剂（QoI）；啶酰菌胺+吡唑醚菌酯（百可得）；氟酰胺，一种羟基苯胺类（Hyd）；嘧霉胺和环丙唑醇，苯胺嘧啶类；咯菌腈，一种苯基吡咯类；以及咯菌腈+环丙唑醇（适乐时）。啶酰菌胺、吡唑醚菌酯、百可得、氟酰胺、环丙唑醇和嘧霉胺各自的抗药频率分别为85.4%、86.5%、86.0%、44.4%、52.7%和59.5%。总体而言，分别有17.8%和19.8%的分离株对咯菌腈和适乐时表现出敏感性降低。预防性喷洒在离体草莓果实上的所有杀菌剂，除咯菌腈和适乐时外，均无法控制对每种杀菌剂具有高抗性水平的分离株。在佛罗里达州灰葡萄孢菌群体中检测到四种多药抗性（MFR）表型。对来自不同化学组的一种杀菌剂（FR1）、两种（MFR2）、三种（MFR3）和四种（MFR4）杀菌剂具有抗性的分离株分别占总抗性群体的5.9%、28.6%、41.8%和23.7%。MFR3分离株占主导地位，包含两个亚群体，即啶酰菌胺-QoI-苯胺嘧啶类分离株（56.5%）和啶酰菌胺-QoI-氟酰胺分离株（40.6%）。除了报告对啶酰菌胺和QoI杀菌剂具有极高抗性的群体外，我们还展示了灰葡萄孢广泛存在多药抗性的证据，这就需要立即实施新的管理策略，以阻止更多抗性群体的发展。
