Plant pathogenic fungi are the main causative agents of diseases associated with significant productivity and economic losses in agriculture. Thus, the rapid and early identification of plant pathogens is essential for directing effective management and control strategies for diseases to prevent or reduce their severity. The objective of this study was to characterize and discriminate different species of plant pathogenic fungi using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and chemometric analysis. Five fungal species of the genera Colletotrichum, Fusarium, Macrophomina, Neoscytalidium, and Pseudofusicoccum, isolated from agricultural crops, fruit trees, and ornamental plants, were used. Discrimination of the fungal samples was conducted using different fingerprint regions of ATR-FTIR spectra and partial least squares-discriminant analysis (PLS-DA). The results showed that regions I (800–1800 cm⁻¹) and III (800–1800 and 2800–2990 cm⁻¹) can be used as spectroscopic biomarkers for the differentiation and classification of fungi by ATR-FTIR, as PLS-DA revealed adjustment quality and satisfactory prediction, generating values of R² = 0.96 and Q² = 0.60 in cross-validation. The most relevant infrared absorption bands in the separation of classes were the C–O stretching vibrations, bending of C-H bonds, amide III bands, and C–C stretching. This method can be an important diagnostic tool in the agricultural sector for disease management, considering that it can provide biological differentiation and/or similarity between fungal species.

植物病原真菌是与农业生产力和经济损失相关的疾病的主要病原体。因此，快速、早期识别植物病原体对于指导疾病的有效管理和控制策略以预防或减轻其严重程度至关重要。本研究的目的是利用衰减全反射傅里叶变换红外 (ATR-FTIR) 光谱和化学计量分析来表征和区分不同种类的植物病原真菌。使用从农作物、果树和观赏植物中分离出的炭疽菌属、镰刀菌属、大孢霉属、新胞霉属和拟梭菌属的五种真菌。使用 ATR-FTIR 光谱的不同指纹区域和偏最小二乘判别分析 (PLS-DA) 来区分真菌样品。结果表明，I区（800-1800 cm ^-1）和III区（800-1800和2800-2990 cm ^-1）可作为ATR-FTIR对真菌进行区分和分类的光谱生物标志物，如PLS-DA显示了调整质量和令人满意的预测， 在交叉验证中生成 R ²  = 0.96 和 Q ² = 0.60 的值。类别分离中最相关的红外吸收带是 C-O 伸缩振动、CH 键弯曲、酰胺 III 谱带和 C-C 伸缩。该方法可以成为农业部门疾病管理的重要诊断工具，因为它可以提供真菌物种之间的生物区分和/或相似性。