Photosynthetic Characteristics of the Transgenic rolB-pttGA20ox Double Genes Populus tomentosa Carr.

In order to study the photosynthetic characteristics of the transgenic rolB-pttGA20ox double genes Populus tomentosa Carr.,one-year-old potted seedlings of 4 transgenic clones(RG-1~RG-4)and a control clone(PT-1616)were used as experimental materials for the measurement of photosynthesis using Li-6400.The correlation between photosynthetic and growth characteristics was also analyzed.The results showed that the light response curves of net photosynthetic rate of the five clones were similar to each other,and the net photosynthetic rate of RG-1,RG-3 and RG-4 were higher than that of the control clone with the same photosynthetic active radiation.The light compensate points of all the 4 transgenic clones were lower than that of the control clone,but the light saturation points of RG-3 and RG-4 were higher than that of the control clone;The difference of net photosynthetic rates between different clones was significant,with RG-4 being the highest;The net photosynthetic rate of transgenic clones were correlated significantly with their ground diameters,while not significantly related to the seedling height.