Study On Ri Plasmid Tansformation And Exogenous Gene Expression Of Triploid Chinese White Poplar (Populus Tomentosa)

In this study, three Agrobacterium rhizogenes bacterial strains 30148, 15834 and ZALF infected the leaf explants of triploid Chinese white poplar, the hairy roots were obtained from leaf explants. Hairy root in vitro culture system was established, hairy root regeneration plant was induced at containing different hormone culture. Transformed plant of triploid Chinese white poplar was confirmed by the shape characteristic, agropine analysis, PCR analysis. Indicated that T-DNA of Ri plasmid had already been combined into in the regeneration plant91% of transgenic plant of the triploid Chinese white poplar leaf showed winkle symptom compared with the contrast , the others grew normally. The leaves of transplant had the characteristic of the spontaneous root in MSo medium. The rate of rooting, length of roots, number of roots, height of plant and phenotypic variation of transgenic triploid Chinese white poplar clone were studied. Results showed that: rate of rooting of transgenic triploid Chinese white poplar was increased significantly and had extensive root system compared with the contrast , the number of root of 78% transplant clone was increased compared with the contrast and the lateral roots formed a cluster and developed well , ability of rooting was increased significantly ; The seedlings of transplant had a remarkable difference in leaf shape , leaf area , petiole length and Stem length compared with the contrast, majority showed that leaf withered , long / wide increased , leaf area decreased , petiole length reduced and growth of high decreased .The clones were selected such as 3. 07, 3. 28, 3. 63 which grew normally and had little variation in growth.About 30 different transgenic clones were selected from A. rhizogenes 30148 triploid Chinese white poplar transplant and chlorophyll content and photosynthesize rate of function of leaves were measured. Results showed as below: content of chlorophyll had significant difference among different transgenic clone, only two transgenic clones had low content of chlorophyll b , other transgenic clones content of chlorophyll a, chlorophyll b had a linear correlation with chlorophyll (a+b); Photosynthesize rate of 85% transgenic clones were lower than the contrast, content of chlorophyll of transgenic clones had no correlation with photosynthesize rate , photosynthesize rate of transgenic clones had positive correlation with growth of hight.