*2.1. Pigments Content Analysis*

The leaves of *C. sinense* 'Red Sun' show red at the leaf bud stage. With the development of the leaves, the leaves gradually change from red to yellow, and finally the mature leaves develop into green with a little yellow color at the tip, as seen in Figure 1. The color of leaves was affected by a variety of pigments, including the contents of chlorophyll, carotenoids, total flavonoids and total anthocyanins in *C. sinense* 'Red Sun'. The results showed that the maximum contents of the four pigments were found at the red leaf stage, while the minimum contents were shown by leaves at yellow stage. The contents of all four pigments in green leaves were higher than those in yellow leaves, but lower than those in red leaves (Figure 2).

**Figure 1.** Phenotypes of *Cymbidium sinense* 'Red Sun' red leaves (RL) (**a**), yellow leaves (YL) (**b**) and green leaves (GL) (**c**).

**Figure 2.** Chlorophyll (**a**), carotenoids content (**b**), total flavonoid (**c**) and total anthocyanin (**d**) content of different color leaves of *Cymbidium sinense* 'Red Sun'. Bars represent the mean of three biological replicates ±SE. Lowercase letters indicate significant differences at *p* < 0.05.
