Study on Biological Characteristics and Formation Mechanism of Flower Color Chimera in Chrysanthemum
|Course||Ornamental Plants and Horticulture|
|Keywords||chrysanthemum flower color chimera biological characteristics proteomics gene cloning|
Chrysanthemum (Chrysanthemum morifolium) is a perennial root flower in Chrysanthemum(Composite), one of the four cut flowers in the world, with many kinds of values like ornamental, medical and edible values. The chrysanthemum color chimera with varieties of morphological characters, possessing high ornament value, is an important species resource in breeding, as well as an ideal material for studying the color inheritance and mechanism of formation and regulation. A yellow-purple bi-color chimera was studied as experiment material, maintaining the chimera characters using the regular cutting propagation. However, the formation mechanism of the chimeric flower color is not clear.In this study, a chrysanthemum color chimera mentioned above was studied as experiment material, preliminary studying about the biological characteristics and the main components of the petal flower pigments, analyzing the flower color differential expression of proteins related to flower color, then cloning the sequence of cDNA that related with the color formation. The results of this study are listed as follows.1. Through investigation and analysis of the biological characteristics in chrysanthemum color chimera, it revealed that the flower bud differentiation began in early August and completed in around 60 days, with flowering stage ( the days between the cutting and initial flowering stage) of 199 days and five major color morphologies. Based on this, the gardening treatment was conducted, showing that the influences of the cutting dates and the pinching times on the blooming date were not obvious.2. According to investigating and analyzing of genetic stability of the test materials applying morphology, cultivation science and tissue culture techniques, it turned out that the percentage of flower color chimera was 47.37%, while that of whole yellow plants was 52.63%; among the flower color chimeras, chimeric color flowers was 70%; a pure yellow strain had been studied out owning to the successful separating and fixing chimeric characters by tissue culture of chimera axillary buds.3. With the extracts of different color petals as experiment materials, the ultra-visible spectroscopic analysis and specific color reactions were performed, indicating that the pigment of the yellow petal was chalcone substances and the purple one was chalcone substances and anthocyanins in preliminary analysis.4. Based on the SDS-PAGE technology, the difference bands were detected from the different color petals proteins, while the diversities between proteins of the leaves on the branches with different color petals were slim. In the further study with IPG-IEF/SDS-PAGE analysis, 139 protein spots of differential expression were detected, 10 of them were identified by MALDI-TOF-TOF-MS, respectively involving energy metabolism, material metabolism and gene regulation physiological processes. CHI expressed markedly higher in yellow petals than purple and F3H specifically expressed in purple petals, which are the key enzymes in the synthesis pathway of anthocyanin. It was speculated that both of them were related to the formation of the chimeric flower color.5. According to the analysis of flower pigment and identification of the differential proteins, the full-length cDNA sequences of CHI and F3H were cloned applying molecular biology technology in the chrysanthemum petals. The coding region sequence of CHI was 714bp and coded 237aa, homologous alignment of which showed that the homology with the other seven kinds of compositae plants is 67-96%. The coding region sequence of F3H was 1074bp and coded 357aa, homologous alignment of which detected that it was quite conservative. The cloning of the CHI and F3H genes provide experimental basis for the formation mechanism of the further study on the chimeric flower color.