Fig. 7
Two-dimensional principal component analysis showing (a) the multivariate variation in terms of metabolite concentrations among seeds and seedlings derived from 8 open-pollinated winter oilseed rape genotypes cultivated under control and drought stress conditions in a semi-controlled container trial. All biological replicates are shown. Seedlings from maternal control conditions are shown in blue, seedlings from maternal stress conditions are shown in red. Proximity between samples indicates similarity in metabolite patterns. The axes show the first and second principal component along with the variation explained by them in brackets. (b) The same data set now represented as variable vectors indicating the strength and direction of each seed component and seedling metabolite. Vectors which are perpendicular to each other show independence of the component, vectors pointing in opposite directions show a negative correlation, while vectors with a small angle between them show a positive correlation. The color denotes the weight of the contribution to the total variation in the data set, with higher values meaning a stronger contribution. Amino acids are abbreviated as 3 letter IUPAC code. Fatty acids are named without the extension “acid”. TSW: Thousand seed weight, FW: Fresh weight