| Ziziyphus mauritiana Lam. is known for high yield and good quality. But its content of soluble sugar and resistance to coldness are worse than Ziziphus jujuba Mill.. The hybrid induced by the combination of their advantages can improve the quality of fruit, and increase the cultivable area. This is the first time to establish Ziziphus jujuba protoplast electrofusion procedure in order to create new germplasm and breed new cultivars.In this study protoplast isolation and purification methods were developed and optimum parameters of protoplast fusion for Ziziyphus mauritiana Lam. and Ziziphus jujuba Mill.were determined. The main results as follows:1. Leaves of in vitro plants and suspension culture was studied. The results showed viability of protoplasts isolated from leaves was significantly higher than that of suspension culture. But for yield of protoplasts the result was just the opposition.2. The optimal enzyme solution used for protoplasts isolation for Ziziyphus mauritiana Lam was Cellulase10g/L+Macerozyme 4g/L+Mannital 0.7mol/L. and The optimal enzyme solution used for protoplasts isolation for Ziziphus jujuba Mill was Cellulase15g/L+Macerozyme 4g/L+Mannital 0.7mol/L.3. Yield of Ziziyphus mauritiana Lam. protoplast was highest when 5g/L Macyorozyme was used. The highest yield of Ziziphus jujuba Mill protoplast was obtained when 4g/L Macyorozyme was used. Viabilty of Ziziyphus mauritiana Lam. and Ziziphus jujuba Mill.protopalsts were highest when 4g/L Macyorozyme was used. So 4g/L Macyorozyme should be the optimal.4. Yield and vigor of Ziziyphus mauritiana Lam. and Ziziphus jujuba Mill.protoplasts were highest when enzyme was used for 14—16hours.5. The optimum electric parameters were alternating current (AC) 100V/cm,duration 50sdirect current (DC ) intensity 1000 V/cm,50μs per hours for electrofusion in Ziziphus jujube.6. When the fusion proportion of Ziziyphus mauritiana Lam. and Ziziphus jujuba Mill. Protoplast wasl to 2 and fusion density was 5×104/ml, 18 percent of pair fusion was obtained. |
