Rice bakanae disease is a soil-borne disease mainly caused by Fusarium fujikuroi, which seriously damages the yield and quality of rice. Phenamacril targets Myosin-5, thereby inhibiting its ATPase activity to exert an antifungal effect, demonstrating significant bioactivity against Fusarium species. However, the resistance of Fusarium fujikuroi field populations to phenamacril in Jiangsu Province in recent years remains unclear. In this study, a total of 223 Fusarium fujikuroi isolates were collected in Jiangsu Province from 2022 to 2023, with the resistance frequency increase from 25.88 % to 49.28 %. Additionally, a novel mutation type (S420I) in FfMyosin-5 was identified and confirmed by genetic transformation. The compound fitness index (CFI) revealed that the fitness of FfMyosin5(S420I) point mutants (1 x 10(5) < CFI <= 2 x 10(5)) was significantly lower than sensitive strain (CFI = 10.26 x 10(5)) in terms of mycelial growth rate, conidia production and conidia germination. In summary, the S420I mutation in FfMyosin-5 induces resistance to phenamacril while also decreased the fitness of Fusarium fujikuroi.

来源平台：PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY