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ž@Field Informatics
ž@Field of Research on Crop Production Management Systems
ž@Field of Research on the Function and Regulation of Animal Production
ž@Field of Research on Crop Genomic Breeding
ž@Field of Research on Fruit Tree Genomic Breeding
Ÿ@Field of Research on the Development and Utilization of New Breeding Materials for Ornamental Plants

Outline of field of research on the development and utilization of new breeding materials for ornamental plants
EDevelopment of ornamental plants by interspecific hybridization and gene transfer
EDevelopment of DNA markers for the breeding of ornamental plants
EResearch on flower morphogenesis, flower physiology, and biosynthesis of floral pigments



Takashi Onozaki
@There are varietal differences in resistance among many flower diseases, and the possibility of breeding for disease resistance is shown. Bacterial wilt is one of the most important and damaging diseases of carnation in Japan. We developed a DNA marker tightly linked to a major resistance gene. The vase life of cut flowers is one of the most important characteristics that determine a cultivarfs quality and ability to satisfy consumer preferences, thereby stimulating repeat purchasing. We developed two cultivars, eMiracle Rougef and eMiracle Symphonyf, with genetically determined long vase lives of about 20 days (3 times that of control cultivar, eExcereaf). At present, with regard to flower vase life and disease resistance, we work on research using dahlias and lisianthus.
 

Left: Two carnation cultivars, eMiracle Rougef and eMiracle Symphonyf with genetically determined long vase lives.
Right: Morphology of dahlia flowers with four senescence patterns: (A) wilting, (B) wilting with browning, (C) browning, (D) petal abscission.





Takaaki Nishijima
@@Although the flowers of many wild species are thoroughly beautiful, they have been improved to become more attractive in the process of breeding as horticultural plants. Do you know what changes made the flowers attractive? I believe that two factors are important: making a flower bigger-bloomed and more decorative. In flowers that are widely loved, such as chrysanthemum, rose, and carnation, there are varieties that have big-bloomed flowers not seen in wild species, or that have decorative flowers such as the full double flower. However, breeding of a big-bloomed variety or improvement of flower shape to make the flower more decorative usually takes a long time?from several dozens to several hundreds of years. If the mechanisms that determine the size and shape of the flower were to be revealed, methods of improving flowers to make them attractive in a short time could be elucidated. If this were to be realized, it might be possible to produce new horticultural plants from previously neglected plants. We are tackling our research with these hopes.
@@We have found that cytokinin and gibberellin can enlarge flowers size. Currently, we are investigating how the synthesis and signal transduction systems of these physiologically active substances are related to the improvement of flower size by breeding.

Photo: Enlargement of petunia flowers by cytokinin (CPPU)
¦Numbers in the figure are CPPU concentrations (ƒÊmol/lj


Masayoshi Nakayama
@A flower has not only a specific morphology but also unique colors or scents compared with the other organs of the plant. These are important factors that determine the commercial value of an ornamental flower. To solve basic problems of flower color expression, we select target ornamental flower plants appropriate for the goal of our research using biological organic chemistry and molecular biology methods, as well as horticultural methods. The goal is to deepen our understanding of the flower organ and contribute to the production of ornamental flowers with high commercial value.

@We are attempting to elucidate the mechanisms of expression of flower colors as well as the formation of marginal variegation patterns. Some flowers have co-pigments that are colorless compounds to influence the coloration of pigments. We are studying the structural relationship between co-pigments and pigments to generate co-pigmentation effects. Marginal variegation is a coloration pattern whereby the color at the marginal tissue is different from that of the inner tissue of a flower. The coloration pattern is produced by site-specific synthesis of pigments. We are also investigating the mechanism to regulate pigment biosynthetic activity and to determine position differentiation in marginal variegation flowers.