Columbia Basin Agricultural Research Center, Oregon State University, Adams, OR 97810.
Soil and Water Conservation Unit, United States Department of Agriculture-Agricultural Research Service, Adams, OR 97810.
Plant Dis. 2021 Jan;105(1):169-174. doi: 10.1094/PDIS-10-19-2125-RE. Epub 2020 Nov 10.
is the causal agent of Septoria tritici blotch (STB), a disease of wheat () that results in significant yield loss worldwide. 's life cycle, reproductive system, effective population size, and gene flow put it at high likelihood of developing fungicide resistance. Succinate dehydrogenase inhibitor (SDHI) fungicides (FRAC code 7) were not widely used to control STB in the Willamette Valley until 2016. Field isolates of collected in the Willamette Valley at dates spanning the introduction of SDHI (2015 to 2017) were screened for sensitivity to four SDHI active ingredients: benzovindiflupyr, penthiopyrad, fluxapyroxad, and fluindapyr. Fungicide sensitivity changes were determined by the fungicide concentration at which fungal growth is decreased by 50% (EC) values. The benzovindiflupyr EC values increased significantly, indicating a reduction in sensitivity, following the adoption of SDHI fungicides in Oregon ( < 0.0001). Additionally, significant reduction in cross-sensitivity among SDHI active ingredients was also observed with a moderate and significant relationship between penthiopyrad and benzovindiflupyr ( = 0.0002) and a weak relationship between penthiopyrad and fluxapyroxad ( = 0.0482). No change in cross-sensitivity was observed with fluindapyr, which has not yet been labeled in the region. The results document a decrease in SDHI sensitivity in isolates following the introduction of the active ingredients to the Willamette Valley. The reduction in cross-sensitivity observed between SDHI active ingredients highlights the notion that careful consideration is required to manage fungicide resistance and suggests that within-group rotation is insufficient for resistance management.
是小麦叶斑病（STB）的病原体，这种疾病会导致全球小麦产量的显著损失。 的生命周期、繁殖系统、有效种群规模和基因流使其极有可能产生抗药性。琥珀酸脱氢酶抑制剂（SDHI）杀菌剂（FRAC 代码 7）直到 2016 年才被广泛用于控制威拉米特谷的 STB。在引入 SDHI （2015 年至 2017 年）的跨度内，从威拉米特谷采集的 分离株被筛选对四种 SDHI 活性成分的敏感性：苯并维氟氯吡、戊唑嘧菌酯、氟唑环菌胺和氟啶吡菌胺。通过真菌生长抑制 50%的杀菌剂浓度（EC 值）确定杀菌剂敏感性变化。苯并维氟氯吡 EC 值显著增加，表明在俄勒冈州采用 SDHI 杀菌剂后，敏感性降低（<0.0001）。此外，还观察到 SDHI 活性成分之间的交叉敏感性显著降低，戊唑嘧菌酯和苯并维氟氯吡之间存在中度且显著的关系（=0.0002），戊唑嘧菌酯和氟唑环菌胺之间存在弱关系（=0.0482）。在该地区尚未标记的 fluindapyr 中未观察到交叉敏感性变化。研究结果记录了在活性成分引入威拉米特谷后， 分离株中 SDHI 敏感性的降低。观察到 SDHI 活性成分之间交叉敏感性的降低突出了一个观点，即需要仔细考虑管理杀菌剂抗性，并表明组内轮换不足以进行抗性管理。
