Fig. 4
Principal component analysis (PCA) two-dimensional score plot for identifying relationships between different light treatments on Brassica rapa var. chinensis. Colored ellipses (size determined by a 0.95-probability level) show the observations grouped by treatment. The legend indicating various light treatments is as follows: 4L, 12P (75 µmol m−2 s−1 light intensity and 12:12 h light:dark photoperiod); 4L, 6P (75 µmol m−2 s−1 light intensity and 6:6:6:6 h light:dark:light:dark photoperiod); 8L, 12P (150 µmol m−2 s−1 light intensity and 12:12 h light:dark photoperiod); 8L, 6P (150 µmol m−2 s−1 light intensity and 6:6:6:6 h light:dark:light:dark photoperiod); Blue (blue spectrum); Magenta (magenta spectrum); NL (natural light); and Red (red spectrum)