Wang Yan-Fen, Hao Fang-Min, Zhou Huan-Huan, Chen Jiang-Bo, Su Hai-Chuan, Yang Fang, Cai Yuan-Yuan, Li Guan-Long, Zhang Meng, Zhou Feng
School of Resources and Environment, Henan Institute of Science and Technology, Xinxiang 453003, China.
College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China.
J Fungi (Basel). 2022 Aug 11;8(8):839. doi: 10.3390/jof8080839.
Melon Fusarium wilt (MFW), which is caused by Fusarium oxysporum f. sp. melonis (FOM), is a soil-borne disease that commonly impacts melon cultivation worldwide. In the absence of any disease-resistant melon cultivars, the control of MFW relies heavily on the application of chemical fungicides. Fludioxonil, a phenylpyrrole fungicide, has been shown to have broad-spectrum activity against many crop pathogens. Sensitivity analysis experiments suggest that fludioxonil has a strong inhibitory effect on the mycelial growth of FOM isolates. Five fludioxonil-resistant FOM mutants were successfully generated by repeated exposure to fludioxonil under laboratory conditions. Although the mutants exhibited significantly reduced mycelial growth in the presence of the fungicide, there initially appeared to be little fitness cost, with no significant difference (p < 0.05) in the growth rates of the mutants and wild-type isolates. However, further investigation revealed that the sporulation of the fludioxonil-resistant mutants was affected, and mutants exhibited significantly (p < 0.05) reduced growth rates in response to KCl, NaCl, glucose, and mannitol. Meanwhile, molecular analysis of the mutants strongly suggested that the observed fludioxonil resistance was related to changes in the sequence and expression of the FoOs1 gene. In addition, the current study found no evidence of cross-resistance between fludioxonil and any of the other fungicides tested. These results indicate that fludioxonil has great potential as an alternative method of control for FOM in melon crops.
甜瓜枯萎病（MFW）由尖孢镰刀菌甜瓜专化型（FOM）引起，是一种土传病害，在全球范围内普遍影响甜瓜种植。在没有抗病甜瓜品种的情况下，甜瓜枯萎病的防治严重依赖化学杀菌剂的使用。咯菌腈是一种苯基吡咯类杀菌剂，已被证明对许多作物病原菌具有广谱活性。敏感性分析实验表明，咯菌腈对FOM分离株的菌丝生长具有强烈的抑制作用。在实验室条件下，通过反复接触咯菌腈，成功获得了5个抗咯菌腈的FOM突变体。虽然这些突变体在杀菌剂存在的情况下菌丝生长显著减少，但最初似乎没有明显的适合度代价，突变体和野生型分离株的生长速率没有显著差异（p < 0.05）。然而，进一步研究发现，抗咯菌腈突变体的孢子形成受到影响，并且突变体在对KCl、NaCl、葡萄糖和甘露醇的反应中生长速率显著降低（p < 0.05）。同时，对突变体的分子分析强烈表明，观察到的咯菌腈抗性与FoOs1基因的序列和表达变化有关。此外，目前的研究没有发现咯菌腈与任何其他测试杀菌剂之间存在交叉抗性的证据。这些结果表明，咯菌腈作为甜瓜作物中防治FOM的替代方法具有巨大潜力。
