Preliminary Studies On Establishment Of Genetic Transformation System In Euphorbia Pulcherrima Willd

Poinsettia (Euphorbia pulcherrima Willd.), a plant of Euphorbiaceae family (Euphorbia), is one of the most important pot plants at home and abroad. The wholesale poinsettia market worldwide produces 200 million poinsettia plants each year. Flowering time of poinsettia that cannot be changed by convention breeding technology is controlled by flowering regulation methods, such as using modern greenhouses and much energy consumption. Techniques of gene engineering (including introduction flowering-related gene into poinsettia for regulating expression of flowering genes) provide a important way to chang flowering time of poinsettia.The leaves of'Velvet'were used as the explants to study callus, bud and root of differentiation. And the plant regeneration systemt of poinsettia was established. the poinsettia('Velvet') embryogenic callus was taken as the explants,then the arabidopsis flower meristem-specific genes AP1 genes were transferred into the poinsettia,and the genetically modified material was identified .The main findings are as follows:(1) By the selection of the optimal explant, the different time of sterilization and anti-browning additives, and study on different chormones combination effect on callus induction, shoot induction and root induction, a stable poinsettia regeneration system was esstablished. The optimal medium for callus induction:MS+ 6-BA 0.5 mg/L+ 2,4-D 0.5 mg/L+Vc 0.05g/L;the most suitable medium for shoot: MS+NAA 0.5 mg/L or 6-BA 0.5mg/L+NAA 0.1mg/L+Vc 0.05g/L; the most effective medium for root: 1/2MS+ NAA 1.0mg/L+ IBA 1.0mg/L+Vc 0.05g/L; Seedling culture with 1/2MS+NAA 0.5mg/L+IBA0.5mg/L medium is better.(2) Based on the established poinsettia regeneration system, genetic transformation of AP1 gene was carried out with the high quality callus as the primary transformed receptor. And the effect of the cefotaxime and penicillin carboxy bian on poinsettia explant and inhibition effect of agrobacterium growth was disccussed. established the optimal condition was described below. Cephalosporins and penicillin as bacteriostatic agent agent,was 300 mg / L, 250 mg / L respectively; 30mg / L kanamycin was the optimal concentration. Finally, after detected by GUS staining and PCR, parts of the resistant callus was found to appear with dark blue; a DNA fragment of about 700bp was amplified in primer 1, and about 400bp was amplified respectively in primers 2 and 3. So, target genes have been transferred to the poinsettia genome.