Study On The Efficient Adventitious Buds Regeneration System Of 5 Important Chrysanthemum Cultivars

Dendranthema × grandiflorum (Ramat) Kitam. originated from China, is an economically important ornamental plant in many parts of the world. There are many breeding achievements every year including cut flower and pot plants, except blue flower cultivar. Transgenic biotechnology of chrysanthemum, rose from 1970s overcomes the limitations of classical breeding, and as a new breeding instrument transformation focuses on the enhancement of the plants ornamental value through the improvement of flower color, size and form, vegetative height, growth form, sensitivity to light quality/quantity and insect-resistant; speeds up chrysanthemum breeding course; expances the breeding ways of blue flower chrysanthemum. Chrysanthemum regeneration studies have been an important basal work of transformation, with the knowledge that the plant's transformation was fraught with shortcomings: genotype-dependence and low transformation efficiencies.This report describes leaf explants tissue culture of 4 white flower and 1 pink flower cultivars, an efficient regeneration system from leaf disc of cut flower 'He Lan Bai' was also included. The results showed that the tender leaves of chrysanthemum in greenhouse have limited ability of adventitious buds differentiation (<60%), restricted strictly by the genotype, concentration of plant growth regulators, inoculation direction and experimental season, moreover, explants browning is an inevitable problem during the tissue culture. Nevertheless, it is an easier regeneration from leaves of plants in vitro. The optimal propagation media are: 'He Lan Bai', MS without plant growth regulator; 'Bai Shao Yao', MS + NAA 0.05 mg/L; optimal rooting media of these 2 cultivars is 1/2MS + NAA 0.1 mg/L. Leaves from the forth to sixth nodes of 'He Lan Bai' plants in vitro were cut into leaf discs about 0.6cm2, inoculated with the adaxial surface on regeneration medium (MS + NAA 0.5 mg/L + 6-BA 1.0 mg/L), six weeks later the regeneration rate reached 93.55%.These conclusions establishes a solid foundation for further transgenic breeding of blue flower chrysanthemum, provides useful information for study on the regeneration system of chrysanthemum also.