In-field Volatile Analysis Employing a Hand-held Portable GC-MS: Emission Profiles Differentiate Damaged and Undamaged Yellow Starthistle Flower Heads

IntroductionUnderstanding the complex chemical signalling of plants and insects is an important component of chemical ecology. Accordingly, the collection and analysis of chemical cues from plants in their natural environment is integral to elucidation of plant-insect communications. Remote plant locations and the need for a large number of replicates make in situ headspace analyses a daunting logistical challenge. A hand-held, portable GC-MS system was used to discriminate between damaged and undamaged Centaurea solstitialis (yellow starthistle) flower heads in both a potted-plant and natural setting. ObjectiveTo determine if a portable GC-MS system was capable of distinguishing between undamaged and mechanically damaged plant treatments, and plant environments. MethodologyA portable GC-MS utilising needle trap adsorbent technology was used to collect and analyse in situ headspace volatiles of varying yellow starthistle treatments. Principal component analysis (PCA) was used to distinguish treatments and identify biomarker volatiles. Analysis of variance (ANOVA) was used to determine differences between treatment volatile amounts. ResultsThe portable GC-MS system detected 31 volatiles from the four treatments. Each GC-MS run was completed in less than 3min. PCA showed four distinct clusters representing the four treatments - damaged and undamaged potted plant, and damaged and undamaged natural plant. Damage-specific volatiles were identified. ConclusionThe portable GC-MS system distinguished the treatments based on their detected volatile profiles. Additional statistical analysis identified five possible biomarker volatiles for the treatments, among them cyclosativene and copaene, which indicated damaged flower heads. Copyright (c) 2015 John Wiley & Sons, Ltd. A hand-held, portable GC-MS system was used to discriminate between damaged and undamaged Centaurea solstitialis (yellow starthistle) flower heads in both a potted-plant and natural setting. Principal component analysis (PCA) was used to distinguish treatments and identify biomarker volatiles. The portable GC-MS system distinguished the treatments based on their detected volatile profiles. Statistical analysis identified five possible biomarker volatiles for the treatments, among them cyclosativene and copaene, which indicated damaged flower heads.