Cotton Transformant With Bar Gene And Physiology Of Its Resistance To Phosphinothricin

The weeds have serious disservice in the production of cotton. Genetic engineering plays a major role in further improving the yield, stress-tolerance and quality of fiber. Cotton, Gossypium hirsutum L.,is an economically important crop. It is an important cash crop in human life. So, it has developed for breeding new crop varieties with good synthtical characteristics cotton veriety has important signification biology technology. Bar gene, a gene which detoxifies the field and the ingredient of the herbicide PPT, serves as a mark gene in screening produre for transformants, and plays a role in new material creation for Bialaphos-resistant GM crops as a herbicide-resistant gene.This research used the way of Agrobacterium tumefaciens-mediated transfor-mation on shoot to get transgeinc cotton.We have produced the transgenic plants which were detected to have bar gene. Now, the research result as follow:1.The PPT selective concentration is made sure as 5mg/L in differentiation phases of baimian 1.2. The transgenic plants of cotton were obtained:The transgenic plants which regenerated in the PPT medium were examined by GUS histochemical staining, distinctive PCR and squashing leaves,indication that bar gene already tranfomed into the genome og cotton; Graft can not only improved the root regeneration frequencies but also improved the survival efficiencies of transgene plant more than 90 percent. Comparing grafting in-vitro with grafting in-vivo, more transgenetic plantlets were obtained with grafting in-vivo;3.We studied effects of different PPT concentrations on root growth and development, chlorophyll, photosynthesis and glutamine synthetase activity under hydroponic cultured in greenhouse. The results showed that the total root surface area, total root length and total root volume significantly decreased when PPT concentration was 1 mg/L, to maximum at 5 mg/L concentration of PPT; In the transgenic cotton, the development of root was inhibited not significantiy when PPT concentration was 5 mg/L. The activity of glutamine synthetase was reduced significantly as the concentration of PPT increased. It maybe ammonium’s accumulation inhibited root growth, thus decreased the activity of root and glutamine synthetase; but in the transgenic cotton, it can avoid intoxication because of bar gene encoding phosphinothricin acetyltransferase. The chlorophyll a, chlorophyll b,total chlorophyll content and chlorophyll per gram decreased significantly when PPT was 5mg/L in euphylla; in the transgenic cotton, the content of chlorophyll a changed not significantly when the concentration of PPT smaller than 6mg/L, the changes significantly when the concentration of PPT exceed 7mg/L; total chlorophyll content and chlorophyll per gram decreased not significantly. The velocity of photosynthetic and GS activity in scion were reduced as PPT concentration rised. The velocity of photosynthetic decreased 9.6% and the GS activity in scion decreased 19.9% compared with CK, however, the GS activity in leaf did not decrease as PPT concentration enhanced; in the transformed cotton. The velocity of photosynthetic and GS activity in scion were changed...