Studies On Agrobactericum-Mediated Transformation Systems Of Torenia Fournieri Lind. And Portulaca Grandiflora Hook.

It has been an important aspect that the color of flower was improved by means of genetic engineering in ornamental plants. In this research, we constructed the expression vectors, which contain exogenous gene chalcone systhase (CHS) antisense gene of Gerbera hybrida and transformed it into Agrobacterium LBA4404 through freezing-melting. An efficient regeneration system and transformation system have been estadblished on leaf discs of Torenia fournieri Lind. Transformation systemes also have been established on calli and devision leaves of Portulaca grandiflora Hook. Putatively transformed shoots all attained from Torenia fournieri Lind. and Portulaca grandiflora Hook..The ability of calli formation of different torenia explants is distinct. The explants with roots have the highest frequency of torenia calli induction. Calli can be multiplicated by reducing the concentration of the hormone. On MS+NAA 0.1 mg/L+6-BA 2 mg/L medium, buds can be high induced on the leaf of Torenia fournieri Lind. and there are more buds numbers on the MS+NAA 0.1 mg/L+6-BA 0.5 mg/L medium. If 0.1mg/L NAA is added in the MS medium, many roots form quickly. As a selectable agent, concentration of kanamycin is different with medium of buds induction. Concentration of kanamycin is higher in the medium that has higher frequency of buds induction. Concentration of selectable agent is 300mg/L on the MS+NAA 0.1 mg/L+6-BA 0.5 mg/L medium. Cefotaxime can restraint the buds formation, as well as piperacilin. 400mg/L piperaclin can be used in the restrained-medium of torenia transformation. Sonication-assisted Agrobacterium-mediated transformation (SAAT) can increase the efficiency of transformation. 2s sonication can enhance the GUS gene transient expression and induction of resistant buds without leaves incision. Acetosyringone (AS) can increase the GUS gene transient expression when it was added in the suspending medium. Pre-cultured 2 days and co-cultured 6 days can also enhance the efficienty of transformation of Torenia fournieri Lind.The main factors influencing Agrobacterium-mediated genetic transformation of Portulaca grandiflora Hook, are as follows. The concentration of kanamycin of devision leaves and the calli were 100mg/L and 200mg/L, respectively. Calli infection can gain more GUS gene transient expression and resistant tissuses than devision leaves. 2~4s Sonication and co-cultured 6 days can enhance the efficienty of transformation of Portulaca grandiflora Hook. The concentration of Agrobacterium and time of infection can distinctly affect the frequency of resistant tissues.