Detection of fungal infection in Lolium perenne by Fourier transform infrared spectroscopy

The goal of the study was to apply Fourier transform infrared (FTIR) spectroscopy followed by chemometrical data treatment for the differentiation of fungi-infected perennial ryegrass (Lolium perenne) from uninfected grass. FTIR was used to rapidly discriminate between leaves of perennial ryegrass (L. perenne) infected by a fungal endophyte (Epichloe; asexual forms: Neotyphodium) and uninfected leaves. Besides drying and grinding of the sampled leaves, no other preparation steps were needed. FTIR measurements were performed in the attenuated total reflection (ATR) mode. Aliquots of powdered leaf samples were placed on a ZnSe crystal and the spectra were collected, followed by chemometrical analysis (multidimensional factor analysis, hierarchical cluster analysis). ATR-FTIR allowed a rapid detection of fungal infections in the plant material and proved to be a fast and reliable tool for the differentiation of plant biomass without the need of time-consuming sample preparation.