2025/07/29 by Feng Zhou, Haichuan Su, Ruiqi Fu +8 · 1 voice
Agricultural and Biological Sciences · #Fungal Plant Pathogen Control #Plant Disease Resistance and Genetics #Mycotoxins in Agriculture and Food
paper · doi:10.1094/pdis-03-25-0544-re
openalex publication_date 2025/07/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Gray mold of strawberry, which is caused by Botrytis cinerea, is a disease of global importance that seriously affects the yield and quality of strawberry crops. At present, disease control mainly relies on chemical fungicides that prevent fungal growth such as pyrimethanil, an anilinopyrimidine (AP) fungicide. However, the current study, which evaluated the sensitivity of 103 B. cinerea collected from the strawberry fields of Xinxiang City in Henan Province of China, found that all of the field isolates tested had resistance to pyrimethanil, with an average EC 50 value of 49.14 ± 47.87 μg/ml and with 97.09% of the isolates having resistant factors (RF) > 100, indicating high levels of resistance. Further investigation of four highly resistant field isolates (HM-16, HM-38, HM-61, and HM-82) revealed that the phenotype was stably inherited and that resistance was accompanied by a loss of fitness such as significantly (P < 0.05) reduced mycelial growth and spore production, as well as significantly (P < 0.05) reduced spore germination and reduced pathogenicity on detached strawberry leaves. Molecular analysis of the candidate target proteins, BcCGS1 and BcCGS2, identified a range of amino acid changes in the predicted sequences, including D405N, D416E, L28P, M231T, D36G, L121P, A182P, and T200A in BcCGS1 and S48F, S173P, and S104P in BcCGS2. Furthermore, the expression of both genes was found to be significantly (P < 0.05) upregulated in comparisons with the sensitive isolates. In addition, this study confirmed cross-resistance between pyrimethanil and the triazole fungicides hexaconazole, difenoconazole, and tebuconazole, as well as with the dicarboximide procymidone and the strobilurin pyraclostrobin, but no cross-resistance with fludioxonil, pydiflumetofen, iprodione, and fluazinam. Taken together, these results confirm the emergence of pyrimethanil resistance in field populations of B. cinerea in Henan Province, China, as well as further evidence that CGS is the likely target protein for pyrimethanil. Moreover, the data obtained have practical implications for limiting the spread of pyrimethanil resistance and providing more effective disease control.