Karaoglanidis G S, Bardas G
Hellenic Sugar Industry S.A., Plant Protection Department, Sugar Factory of Platy, 59032, Platy Imathias, Greece.
Aristotelian University of Thessaloniki, Faculty of Agriculture, Plant Pathology Laboratory, POB 269, 54006, Thessaloniki, Greece.
Plant Dis. 2006 Apr;90(4):419-424. doi: 10.1094/PD-90-0419.
The control efficacy of two new strobilurin fungicides, trifloxystrobin and pyraclostrobin, against Cercospora beticola isolates resistant and sensitive to sterol demethylation-inhibiting (DMI) fungicides and benzimidazole fungicides and the effects on evolution of resistance were tested in the current study. Control efficacy of strobilurin fungicides was measured using three C. beticola isolates, one DMI-resistant (DMIR), one benzimidazole-resistant (BENR), and one of wild-type sensitivity (WCB). Both pyraclostrobin and trifloxystrobin provided satisfactory control of all the three isolates used in the study, when applied at 5 μg ml and very high levels of control when applied at 10 μg ml. Control was independent of the isolate sensitivity to benomyl and difenoconazole. In contrast, benomyl applied at 10 μg ml failed to control sufficiently the benzimidazole-resistant isolate, whereas difenoconazole applied at either 5 or 10 μg ml failed to provide satisfactory control of the DMI-resistant isolate of the pathogen. The effects of strobilurin fungicide applications on the evolution of resistance to benzimidazole and DMI fungicides were tested under field conditions in a 2-year experiment (2003 to 2004). Applications of either trifloxystrobin or pyraclostrobin provided high levels of disease control during both years of the study, whereas applications of either benomyl or difenoconazole provided a moderate control efficacy. Measurements of resistance frequencies to benomyl and to difenoconazole showed that successive applications of benomyl tended to select for high frequencies of benzimidazole-resistant phenotypes, whereas successive applications of difenoconazole tended to select for high frequencies of DMI-resistant phenotypes. In contrast, applications of either trifloxystrobin or pyraclostrobin prevented an increase of benzimidazole- or DMI-resistant phenotypes compared with the plots treated with benomyl or difenoconazole, respectively, and decreased frequency of resistance compared with untreated control plots.
本研究测试了两种新型甲氧基丙烯酸酯类杀菌剂肟菌酯和吡唑醚菌酯，对甜菜尾孢菌分离株的防治效果，这些分离株对甾醇去甲基化抑制剂（DMI）类杀菌剂和苯并咪唑类杀菌剂分别具有抗性和敏感性，同时还研究了其对耐药性进化的影响。使用三株甜菜尾孢菌分离株测定甲氧基丙烯酸酯类杀菌剂的防治效果，一株对DMI耐药（DMIR），一株对苯并咪唑耐药（BENR），还有一株为野生型敏感（WCB）。当以5μg/ml的浓度施用时，吡唑醚菌酯和肟菌酯对研究中使用的所有三株分离株均提供了令人满意的防治效果，当以10μg/ml的浓度施用时，防治效果非常高。防治效果与分离株对苯菌灵和苯醚甲环唑的敏感性无关。相比之下，以10μg/ml的浓度施用苯菌灵未能充分防治对苯并咪唑耐药的分离株，而以5μg/ml或10μg/ml的浓度施用苯醚甲环唑均未能对病原菌的DMI耐药分离株提供令人满意的防治效果。在2003年至2004年的两年田间试验中，测试了甲氧基丙烯酸酯类杀菌剂的施用对苯并咪唑类和DMI类杀菌剂耐药性进化的影响。在研究的两年中，施用肟菌酯或吡唑醚菌酯均提供了高水平的病害防治效果，而施用苯菌灵或苯醚甲环唑的防治效果中等。对苯菌灵和苯醚甲环唑的耐药频率测量表明，连续施用苯菌灵倾向于选择高频率的对苯并咪唑耐药的表型，而连续施用苯醚甲环唑倾向于选择高频率的对DMI耐药的表型。相比之下，与分别用苯菌灵或苯醚甲环唑处理的地块相比，施用肟菌酯或吡唑醚菌酯可防止对苯并咪唑或DMI耐药表型的增加，并且与未处理的对照地块相比，耐药频率降低。
