Li Tao, Yu Wenbin, Feng Ji, Mao Chengxin, Yu Hong, Liu Aichun, Zhang Chuanqing
Department of Plant Protection, College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, China.
Zhejiang Key Laboratory of Biology and Ecological Regulation of Crop Pathogens and Insects, Hangzhou 310013, China.
Plants (Basel). 2025 Jun 24;14(13):1941. doi: 10.3390/plants14131941.
Strawberry black spot, caused by spp., is an emerging disease that threatens both leaves and fruits during strawberry growth and postharvest storage. This study investigated the boscalid sensitivity of 49 isolates collected from symptomatic strawberry leaves. Boscalid has been widely used to control diseases in strawberry in China for several years. The EC values for the tested isolates ranged from 0.0884 to 266.3289 µg/mL, indicating that most isolates exhibited varying levels of resistance to boscalid based on resistance ratio values. A substitution of SDHC-H134R was detected from most high-resistance isolates. Fitness cost assessment revealed that highly resistant isolates had a reduced conidial germination rate; however, their mycelial growth and conidia production were increased. No significant virulence deficiency was observed, suggesting low fitness cost in resistant isolates. Furthermore, the highly resistant isolates exhibited positive cross-resistance to fluopyram and fluxapyroxad. Molecular docking analysis revealed that the SDHC-H134R mutation reduced the binding affinity between boscalid and mitochondrial complex II. These findings suggest that resistance management strategies, such as fungicide rotation or combinations of fungicides with different action modes, should be implemented to control strawberry diseases, minimizing the development of fungicide resistance and improving overall disease control efficacy.
草莓黑斑病由 spp. 引起，是一种在草莓生长和采后储存期间威胁叶片和果实的新出现病害。本研究调查了从有症状的草莓叶片中收集的49个分离株对啶酰菌胺的敏感性。啶酰菌胺在中国已广泛用于防治草莓病害数年。测试分离株的EC值范围为0.0884至266.3289 µg/mL，这表明基于抗性比值，大多数分离株对啶酰菌胺表现出不同程度的抗性。在大多数高抗性分离株中检测到SDHC-H134R替代。适合度成本评估显示，高抗性分离株的分生孢子萌发率降低；然而，它们的菌丝生长和分生孢子产生增加。未观察到明显的毒力缺陷，表明抗性分离株的适合度成本较低。此外，高抗性分离株对氟吡菌酰胺和氟唑菌酰胺表现出正交互抗性。分子对接分析表明，SDHC-H134R突变降低了啶酰菌胺与线粒体复合物II之间的结合亲和力。这些发现表明，应实施抗性管理策略，如杀菌剂轮换或不同作用方式杀菌剂的组合，以防治草莓病害，最大限度地减少杀菌剂抗性的发展并提高总体病害防治效果。
