Veloukas Thomas, Markoglou Anastasios N, Karaoglanidis George S
Aristotelian University of Thessaloniki, School of Agriculture, Laboratory of Plant Pathology, Thessaloniki, Greece.
Agricultural University of Athens, Pesticide Science Laboratory, 11855 Athens, Greece.
Plant Dis. 2013 Jan;97(1):118-122. doi: 10.1094/PDIS-03-12-0322-RE.
Succinate dehydrogenase inhibiting (SDHI) fungicides constitute a relatively novel fungicide group used for gray mold control caused mainly by Botrytis cinerea. Shortly after registration, resistance was observed in fungal populations that correlated with several mutations in the succinate dehydrogenase complex (complex II). In the current study, 30 B. cinerea isolates possessing five different mutations at three different codons of SdhB (P225F, N230I, and H272L/R/Y) were characterized for their sensitivities to eight SDHI fungicides. The results show different sensitivities and cross-resistance patterns between structurally different SDHIs. P225F mutants were resistant in vitro to all SDHIs tested. Similarly, isolates possessing the H272L mutation were highly resistant to boscalid but showed low to moderate levels of resistance to other SDHIs. The N230I mutants were moderately resistant to boscalid, fluopyram, and fluxapyroxad and showed low resistance levels to isopyrazam, bixafen, fenfuram, benodanil, and carboxin. The H272R mutants showed moderate levels of resistance to boscalid and low resistance levels to isopyrazam, fenfuram, and carboxin but remained sensitive to fluopyram, bixafen, fluxapyroxad, and benodanil. Similarly, the H272Y showed moderate levels of resistance to boscalid and very low resistance levels to isopyrazam, bixafen, fenfuram, and carboxin but showed increased sensitivity to benodanil and fluopyram. Boscalid provided moderate to high control of H272R/Y and N230I mutants in detached fruit assays but provided little control against the H272L and P225F mutants. In contrast, fluopyram controlled H272R/Y mutants and provided moderate levels of control toward H272L, N230I, and P225F mutants. Our findings suggest that sensitivity to SDHIs may vary greatly, dependent on the point mutation in the sdhb subunit.
琥珀酸脱氢酶抑制剂（SDHI）类杀菌剂是一类相对较新的杀菌剂，用于防治主要由灰葡萄孢引起的灰霉病。在登记后不久，在真菌群体中就观察到了抗性，这与琥珀酸脱氢酶复合物（复合物II）中的几个突变相关。在本研究中，对30株在SdhB的三个不同密码子处具有五种不同突变（P225F、N230I和H272L/R/Y）的灰葡萄孢分离株进行了对八种SDHI类杀菌剂敏感性的表征。结果显示，结构不同的SDHI之间存在不同的敏感性和交叉抗性模式。P225F突变体在体外对所有测试的SDHI均具有抗性。同样，具有H272L突变的分离株对啶酰菌胺高度抗性，但对其他SDHI表现出低至中等水平的抗性。N230I突变体对啶酰菌胺、氟吡菌酰胺和氟唑菌酰胺具有中等抗性，对异菌脲、联苯吡菌胺、呋菌胺、苯菌灵和萎锈灵表现出低抗性水平。H272R突变体对啶酰菌胺表现出中等抗性水平，对异菌脲、呋菌胺和萎锈灵表现出低抗性水平，但对氟吡菌酰胺、联苯吡菌胺、氟唑菌酰胺和苯菌灵仍敏感。同样，H272Y对啶酰菌胺表现出中等抗性水平，对异菌脲、联苯吡菌胺、呋菌胺和萎锈灵表现出极低抗性水平，但对苯菌灵和氟吡菌酰胺表现出增加的敏感性。在离体果实试验中，啶酰菌胺对H272R/Y和N230I突变体提供了中等至高的防治效果，但对H272L和P225F突变体几乎没有防治效果。相比之下，氟吡菌酰胺对H272R/Y突变体有防治效果，对H272L、N230I和P225F突变体提供中等水平的防治效果。我们的研究结果表明，对SDHI的敏感性可能有很大差异，这取决于sdhb亚基中的点突变。
