Optimization Of Genetic Transformation System In Chinese Cabbage

An efficient and simple genetic transformation system is the base of analysing genes function and genetic engineering. The pollen were choosen as the receptor of genetic transformation and were treated with ultrasonic wave. The suitable sucrose concentration of pollen suspension and ultrasonic power were studied in this article. Proper kanamycin concentration for selecting transgenic seed was also screened. Furthermore, the bolted Chinese cabbage plants was transformed with vacuum infiltration. The major results were as follows:1. When the pollen were transformed as receptor, 0.4 mol/L sucrose in pollen suspension was proper and could keep the pollen normal morphology.2. Under the condition of eight sonications each lasting 5 s with intervals of 5 s, the best ultrasonic power was 90 W for pollen transformation.3. By observing the change of cotyledons colour and the growth point and the root elongation, the optimal kanamycin concentration for selecting transgenic Chinese cabbage seeds was 30 mg/L.4. The vector pRNAi-RsVPE1 was transformed into Chinese cabbage via vacuum infiltration. A total of 2414 seeds were obtained. The kanamycin concentration 30 mg/L was used to select the transgenic plants. 297 transgenic plants resistant to kanamycin were obtained. Among them, 9 positive transgenic plants were verified by PCR detection, which shows the transgenic efficiency 0.37%. RT-PCR detection showed that the expression level of BraVPE in transgenic plants decreased significantly, which further verified the reliability of transgenic plants obtained. This results laid a foundation for the further study of BraVPE gene functions.