Tissue Culture And Plantlet Regeneration System Establishment Of Davidia Involucrata Baill.

Dove tree (Davidia involucrata Baill.) is a plant species of monomorphic genera belonging to Davidiaceae family, which is one of endemic plant family in China. The dovetree originates from ancientry, belongs to relict of paleotropy flora in Tertiary period. Dove tree has become famous as an ornamental tree for gardens and parks in many countries. And it is called Chinese dove tree, because its capitulum with two white bracts is exactly like a flying dove. In recent years, the increase of regional developing projects has led to sharp decrease of this ancient and rare plant in naturally distributed habitats and natural population. And it is rated as the first class protective plant in China.The research on tissue culture of dove tree will provide a clew and advanced technology for protecting the dove tree resources and its production. So it is very important not only for theoretical research, but also for application.We obtained the regenerative saplings from dormant buds, stems and leaves through the direct as well as indirect way. The factors that affect every step including basic medium, hormone and active carbon are detailedly investigated . As a result, the optimum mediums of every step are screened. A plant regeneration system of Davidia involucrate Baill. was established in this research.Orthogonal design was adopted on initial culture, and the buds were used for inducing sprout of dormant buds, the leaves and stems were used for inducing callus. The results show that the medium WPM+2.0mg/LBA+0.1mg/LNAA is the optimum medium for sprouting of dormant buds. The explants from open air can not used for inducing callus because of disinfectant's phytotoxicity. However, the sterile laminas and leafstalks of regenerative plantlets can be used for inducing callus, and the optimum medium are WPM+2.0mg/LBA+0.5mg/L2,4-D and WPM+2.0mg/LBA+2.0mg/LNAA, respectively.The optimum medium for proliferation are concluded by L9(3~3) orthogonal experiment. The medium WPM+2.0mg/LBA+0.1mg/LZT is propitious to proliferation of buds, and the medium WPM+1.0mg/LBA+0.5mg/LNAA+2.0mg/LZT is propitious to proliferation of callus, the callus could proliferate fast on this medium.The optimum medium for inducing sprout of axillary buds is WPM+2.0mg/LBA, which is concluded by L16(4~4) orthogonal experiment. This medium can be used for the explants from open air also, the ratio of inducement could be up to 91.7%. The optimum medium for inducing differentiation of callus is WPM+3.0mg/LBA+0.5mg/LKT+0.1mg/L...