Study On Transfer By Grobacterium Mediation Into Cucumber (Cucumis Sativus L.)

On the basis of regeneration system of cotyledonary nodes, using Agrobacterium tumefaciens, the Mn-SOD gene was introduced into cucumber plants to express excessively, to improve ability of cleaning ROS and stress tolerance on environmental stress. The new Mn-SOD transgenic materials could be used for study of resistance physiology. Also they would realize variety modification of resistent breeding, and increase plentiful gene resources via genetic engineering in the short time . In this study ,the main results were as follow :Fristly the main factors influencing the plantlet regeneration system from cotyledonary nodes of cucumber (Cucumis Sativus L.) were discussed. The results showed that concentration of plant growth regulation, stage of cotyledonary nodes, types of cutting and implantation of explants, and genotypes all had effect on establishing the regeneration system of cucumber. The optimum culture medium to induce buds was the medium that includes( solid culture medium with MS + 0.005 mg/L TDZ + 0.05 mg/L IBA+ 2 mg/L AgN03 ).Stage three of the cotyledonary nodes, which had two cotyledons separating from its husk and were in bent status with its hypocotyl, gave the maximum number of buds per explants. The best way of cutting was to cut hypocotyl longitudinally and keep one cotyledon while cutting 2/3 and insert vertically. Nongcheng No.3 was the optimum genotype . Buds was beneficial to induce in light .Secondly the sensitivity of cucumber's cotyledon explant to Kan and Cef, the days of preculture, concentrations of Agrobacterium tumefaciens, the days of common culture and the time of being infected on the optimum culture medium were studied. the high frequency transgenic regeneration system of cucumber was established: Stage three of the cotyledons nodes of cucumber, which can′t separate from its husk and green, The best way of cutting was to cut hypocotyl longitudinally and keep one cotyledon while cutting 2/3 and insert vertically,was precultured for 3 days on bud differentiation culture medium (solid culture medium with MS + 0.005 mg/ L TDZ +0.05 mg/ L IBA+ 2 mg/L AgN03), inoculated with EHA-105 Agrobacterium tumefacious for 5 minutes, cocultured for 2 days on culture medium in light , transformed to screening-culture medium (solid culture medium with MS+ 0.005...