Abstract
Reliable detection of potato pathogens via volatile organic compound (VOC) analysis remains challenging because VOC emissions depend strongly on microbial metabolism and host physiology. In this study, gas chromatography-mass spectrometry (GC–MS) data combined with a multivariate chemometric workflow were used to characterize VOC profiles of potato tubers infected with Rhizoctonia solani and Alternaria solani , and to compare these profiles with the emissions produced by the respective fungi grown on LB agar plates. VOCs were collected on thermal desorption tubes and analyzed with GC-MS. Principal component analysis (PCA) and linear discriminant analysis (LDA) achieved high classification accuracies (≥ 80 %) across all sample classes, demonstrating the robustness of the analytical approach. Three C8 oxylipins, 1-octen-3-one, 1-octen-3-ol, and 3-octanone, were associated with R. solani infected potato tubers. For A. solani , 14 diagnostic VOCs were detected in infected tubers, including α-himachalene, β-cedrene, thujopsene, eremophilene, and solavetivone. VOC patterns from LB cultures differed substantially from those observed in infected tubers, underscoring the strong substrate dependence of fungal volatile production. Altogether, this work provides novel host-relevant diagnostic markers for early pathogen detection and demonstrates that chemometric evaluation of complex VOC datasets is a powerful tool for discriminating potato diseases.