Fig. 2

Ecological and genetic differences between purple-flowered and yellow-flowered I. potaninii. (A) Pollen-to-ovule ratio of yellow flowers is slightly higher than purple flowers. (B) The total contents of anthocyanins in purple flowers are significantly higher in comparison with yellow flowers (T-test, P = 0.001, asterisk indicates the 0.01 level). (C) Flavonoid structural gene F3H shows significantly higher expressional level in purple-flowered plants than yellow-flowered ones (logFC > 1, FDR < 0.05). (D)F3H gene is consisted of one (0.84%) start_lost variant, 58 (48.74%) missense variants, and 60 (50.42%) synonymous variants. The start_lost variant and missense variants may deactivate or decline the gene activity of F3H, thus affect the synthesis of anthocyanins and the purple coloration of flowers