Succinate dehydrogenase inhibitors (SDHIs) are an important group of fungicides (FRAC Group 7) for the control of Venturia inaequalis. Mechanisms which lead to reduced SDHI sensitivity in fungi are based on mutations in the SDH-subunits B, C, or D of the target gene. Monitoring studies have shown that most of the European population is still sensitive to SDHIs. Single cases of SDHI resistance have been detected shortly after market introduction although mainly at trial sites. The underlying resistance mechanisms have been identified as target site mutations (B-T258I, C-N85S and C-H151R). However, these were single findings which did not increase in frequency or even disappeared when the same field was analyzed one or more seasons later. This is in contrast to findings on other resistance cases which are stable over several seasons even without selection pressure, such as QoI and benzimidazole resistance. High frequencies of target site mutations for QoIs and benzimidazoles (G143A and E198A, respectively) have been detected in a 2022 survey, whereas no SDHI target site mutation exceeded the detection limit of our molecular detection assay in any sample.

琥珀酸脱氢酶抑制剂 (SDHI) 是一类重要的杀菌剂（FRAC 第 7 类），用于控制黑文氏菌。导致真菌 SDHI 敏感性降低的机制基于靶基因 SDH 亚基 B、C 或 D 的突变。监测研究表明，大多数欧洲人口仍然对 SDHI 敏感。引入市场后不久就发现了 SDHI 耐药性的单例，但主要是在试验地点。潜在的耐药机制已被确定为靶位点突变（B-T258I、C-N85S 和 C-H151R）。然而，这些都是单一的发现，当一个或多个赛季后对同一领域进行分析时，这些发现的频率并没有增加，甚至消失了。这与其他耐药案例的发现相反，即使没有选择压力，其他耐药案例也能在几个季节保持稳定，例如 QoI 和苯并咪唑耐药。在 2022 年的一项调查中，已检测到 QoIs 和苯并咪唑（分别为 G143A 和 E198A）的高频率靶位点突变，而在任何样本中，SDHI 靶位点突变均未超过我们分子检测分析的检测限。