Studies on Flower Color Inheritance and Relations Between Flower Color and Pigments in Cross-breeding Hybrids Between Iris dichotoma and Iris domestica

Both Iris dichotoma and Iris domestica showed excellent resistance to cold, drought and barren stresses, and they can be unprotected for overwintering outdoor in Northern China. The objective of the study was to determine the inheritance pattern of flower pigment and anthocyanin components in hybrid seedlings. When Iris domestica was used as a female parent, all the three relative F₁ plants and F₂ hybrids showed a similar color to their female parent. When Iris dichotoma (purple, yellow, white) acted as a female parent, the flower color of three F₁ plants was purple, brown and violet, respectively, and the flowers of F₂ hybrids had large variations in colors. The colors of the petals were recorded by photographs and indicated by the code number of the Royal Horticultural Society Color Chart (RHSCC). The lightness (L*) of the petal color and two chromatic components a* and b* of the CIE L*a*b* color coordinate were measured by using a Color Reader (CR-400). The results showed that all individuals used in this study were categorized into 9 groups: purple, violet, red, pink, orange, brown, yellow, white and composite color. Twenty-three kinds of anthocyanins were detected from the petals of the hybrid populations by using the high performance liquid chromatography-mass spectrometry (HPLC–MS). Different populations with different genetic background correlated with different types of anthocyanins and different flower colors. Therefore, the knowledge on how the content and type of anthacyanins determining the petal coloration of flowers will help provide information for a comprehensive understanding of the flower color characteristics in hybrid progenies, and it would be also useful for breeding new Iris cultivars with novel flower colors.