Figure 3. PCA ordination plot for India-strain and Pakistan-strain Himalayan balsam rust spectra.

PCA ordination plot for the India-strain and Pakistan-strain Himalayan balsam rust (Puccinia komarovii var. glanduliferae) urediniospore mass spectra (figure redrawn from original Bruker image). Spectra were analyzed by PCA using the Bruker Online Client software, with the components of the first principal component vector shown in the X direction and the components of the orthogonal second principal component vector shown in the Y direction to give the ordination plot. PCA analysis was unsupervised, and all peaks were weighted equally.