Establishment Of The System Of The Triploid China White Poplar And Molecular Identification

Triploid Chinese white Poplar is a native species,which is widely used and high wood-quality. But in the paper puiping process, removing lignin by chemical methods not only lead to very seriously environmental pollution but also increase the cost of paper making . The purpose of our study is to regulate the lignin biosynthesis of Chinese white popular (Populus tomentosa) on molecular level by antisense RNA technology to breed the resourse tree species more suitable for paper making in China. But establishment of the tissue culture and transformation of the triploid Chinese white poplar is very necessary.Here are the main results of the study (1). The system of tissue culture of triploid Chinese white poplar has been established. The regeneration optium culture medium of leaf blades is MS+6-BA (0.25mg/L) + IB A (0.25mg/L) + ZT (0.25mg/L); And the regeneration optium culture medium of stems is MS+IBA (0.25mg/L) + ZT (0.25mg/L) + TDZ (0.1 uM) (2) In order to establishment of the transformation of the triploid Chinese white poplar, the factors influencing the trasformation efficiency of Agrobacterium were also studied. It was found that the presence of acetosyringone increased transformation frequency. Besides, the Agrobacterium concentration, the duration of infection and cocultivation influenced transformation frequency. The optimized condition for transformation triploid Chinese white poplar were co-cultured for 2 days and infected 10-15minutes with Agrobacterium concentration of OD600=0.3. It is benefit to obtain kmr shoots in the coculture medium without CoCl22H2O. There are differences between different Agrobacterium strains and clones.(3) In this study, antisense CCoAOMT cDNA were transformed into triploid Chinese white poplar mediated by Agrobacteriumtumficense. The results of PCR and PCR-Southern conformed that the transgenes had integrated into the triploid Chinese white poplar. Northern dot analysis showed that the antisense cDNAs had expressed at the transcriptional level.(4) We have obtained a lot of Km-resistant triploid Chinese white poplars, and 42 shoots were transferred to the greenhouse , which lay a foundation for regulation of the lignin biosynthesis by gene engineering and biotechnology in Chinese white poplar.