Malgorzata Wesoly, Emma Daulton, Sascha Jenkins, Sarah van Amsterdam, John Clarkson and James A. Covington

In this work, we employed Gas chromatography ion-mobility spectrometry (GC-IMS) technology for early detection of Fusarium basal rot in brown onion, red onion, and shallot bulbs and for tracking disease progression during storage. The volatile profiles of the infected and healthy control bulbs were characterized using GC-IMS and gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). GC-IMS data combined with principal component analysis and supervised methods provided discrimination between infected and healthy control bulbs as early as 1 day after incubation with the pathogen, classification regarding the proportion of infected to healthy bulbs in a sample, and prediction of the infection’s duration with an average R² = 0.92. Furthermore, GC-TOF-MS revealed several compounds, mostly sulfides and disulfides, that could be uniquely related to Fusarium basal rot infection.

Agricultural and Food Chemistry. February 2024