Phenotype Analysis Of Flower Coloration Of Chrysanthemum×morifolium Ramat.

The research was based on the various flower color of chrysanthemums from Beijing, Kaifeng, Japan and Netherlands. The methods of different color measurement (checked using normal eye, the Royal Horticultural Society Colour Chart and spectrophotometer), observation by microscope, UV-visible spectra, specific color reactions and chromatography were used in this dissertation. The most studies focused on the four aspects: the first was the measurement and analysis of flower color; the second was the structure of chrysanthemum petal and flower coloration; the third was the effect of physical and chemical factors on flower coloration; the fourth was the phytochemistry of flower pigments of chrysanthemum petal. The results are indicated as follows:1. The flower color of 5 species of Chrysanthemum and 281 chrysanthemum cultivars mainly including china traditional chrysanthemum groups, which have lots of peculiar flower color, was checked using normal eye, RHSCC and spectrophotometer. Lightness (L^*) and chromatic component (a^* and b^*) of these cultivars are obtained by spectrophotometer. According to the CIELAB color coordinate, all cultivars were divided into nine groups: red, orange, yellow, green, white, pink, purple , grey and other color groups based on the Q cluster analysis. In the same time, the system of flower color measurement of chrysanthemum was discussed.2. The digitization of flower color is very important for the studies of flower color of ornamental plants. Analysis of the CIELAB color coordinate of flower color, the relationship of significant negative correlations between a^* and L^* was founded. That is, from green to red of flower color, the less lightness the flower has. But the significant positive correlation between b^* and L^* was showed in white, pink, purple groups and yellow, red, orange, green groups respectively. Those results show that a^* and b^* are the important factor for lightness and flower coloration.3. The petal was the carrier of flower pigments and the distributing of different pigments in the petal was key to the flower coloration. In this study, free-hand sections of chrysanthemum petal with different color were observed and results are indicated as follows: (1) White flower is the result of refraction of light in the air bladder of petals; (2) the carotenoids in the palisade tissue are the mainly pigment of yellow flowers; (3) the cultivars of red to orange flowers contained carotenoids and anthocyanins in the both upper and lower epidermal cell. The two kinds of flower pigments formed the flower of red and orange synthetically; (4) the purple flower is due to the anthocyanins.4. The color expression of flavonoids in yellow and white cultivars is not sensitive to temperature, light, and pH value. The color expression of anthocyanins of red and purple cultivars is stable under 60 ℃ in methanol and sensitive to light and pH value. Anthocyanins degradate significantly in light. The red color of anthocyanins in some cultivars fades gradually and has a bathochromic shift of λ_vis-max as the increase of pH value in solution. Some metal ions, such as Fe³⁺, Mg²⁺, Al³⁺, Ca⁾=(2+) are positive to red cultivar 'Long Juan Kuang Biao'. Metal ions do not affect flavonoids in cultivar 'Sheng Guang Bai Xue Ji' obviously. These results emphasize that anthocyanins play significant roles in red and purple cultivars of the chrysanthemum. These data is useful for planting and breeding of the chrysanthemum.5. Flower color is the result of refraction of light in the petals. The flower pigments are very important for flower coloration. The study by UV-visible spectra indicate that flower pigments of chrysanthemum are consist of carotenoids, anthocyanins and other flavonoids. The characteristic absorption peak of carotenoids was 440nm and 470nm, the anthocyanin was 530nm, and the other flavonoid was 330nm and 207nm. The pigments of yellow flower is consist of flavone and carotenoids; there is only flavone in white color flower ; the red and purple flower contains anthocyanins and other flavonoids; the orange is formed by carotenoids. anthocyanins and other flavonoids.6. To understand the quantitative effect of major pigments on flower color variation in chrysanthemum cultivars, flavonols(FL), carotenoids(CA), chlorophylls(CH) and anthocyanins(AN) were extracted from the flowers and analyzed both qualitatively and quantitatively with UV-visible spectral. The results indicted that all of the cultivars contain flavonols, which are colorless and act as the co-pigment for some color groups. The anthocyanins were responsible for flower colors of the red, pink, purple, and orange and its content is important for the flower coloration. The relationship of significant negative correlations between total anthocyanins (TA), total carotenoid (TC), total flavonoids(TF) and L^* was founded. The significant positive correlations between TA and a^*, TC and b^* were founded respectively. The content of TC is negatively related to TF and TA, but the content of TF is positively related to TA. At last, according to the content of flower pigments, all cultivars were classified into five groups: FL group, containing flavonols; FL, AN group, anthocyanins and flavonols; FL, CA group flavonols and carotenoids; FL, AN, CA group, anthocyanins, flavonols and carotenoids; FL, CH, CA group, flavonols, chlorophylls and carotenoids. The classification according to flower color and pigments is correlative and this will be benefited for cultivar classification of chrysanthemum.7. In the study of phytochemistry of flower pigments of chrysanthemum petal, the extraction, separation, purification and structural identification of flower pigments were discussed. The carotenoids were extracted by petroleum ether, the anthocyanins were CH₃OH-H₂O-CH₃COOH and the other flavonoids were CH₃OH- H₃COCH₃. The methods of separation of carotenoids, anthocyanins and other flavonoids were founded respectively.At last the key anthocyanin of chrysanthemum was identified as chrysanthemin.