Fig. 4From: Unbiased profiling of volatile organic compounds in the headspace of Allium plants using an in-tube extraction deviceScore (a) and loading (b) plots of PCA of the VOC profiles of the Allium samples. Principal components one and two (PC1, PC2) represent the first two principal components that account for a total of 53.2 % of the variance. Each plot represents an independent plant. In the loading plot, black dots and white triangles represent tentatively identified- and unknown peaks, respectively. All compound names and IDs are listed in the Additional file 3. ID011 2-butenal, 2-ethyl; ID026 3,4-dimethylthiophene; ID091 diallyl disulphide; ID154 2,5-thiophenedicarboxaldehydeBack to article page