Regeneration System In Vitro And Genetic Transformation Of Heading Chinese Cabbage

Heading Chinese cabbage is one of the most important vegetable in Brassica species in China. The genetic engineering provides a new tool for introducing foreign gene into Chinese cabbage to improve its quality. Until now, Agrobacterium-mediated genetic transformation is still the most effectively way used widely by the researchers. The precondition of Agrobacterium-mediated genetic transformation is to establish a high frequency regeneration system. So, Researchers have done much work to improve the shoot regeneration rate in Chinese cabbage. It is thought that there was huge difference between different genotype, which means that the regeneration system established for one certain genotype can't be adapt to another genotype. For each new genotype, it is needed to construct a new regeneration system individually. In this paper, first, a high regeneration system was studied in heading Chinese cabbage, then orf138 gene was tried to transfer into Chinese cabbage by Agrobacterium-mediated genetic transformation. The main results are as follows:1 The effects of hormone, explant types and seedling age on regeneration rate of adventitious bud were studied in this experiment with a pure line 92S105 of heading Chinese cabbage. The results showed that: The maximum shoot regeneration frequency, as 76.19%, was obtained in MS medium supplemented with 0.3 mg/L TDZ and 0.5 mg/L NAA, using the cotyledon with petiole from five days seeding of 92S105 as explants.2 The root medium is 1/2 MS supplemented with 1.0 mg/L IBA or IAA, the root frequency both can reach 100%.3 In the transformation experiment, the sensitivity of regeneration shoot to antibiotics were examined too. The data showed that the two bacteriostats, cefotaxime and carbencillin, both inhibit regeneration rate of regeneration bud, but carbencillin is better than cefotaxime to be used as bacteriostat. 5 mg/L Hyg can be used to select the putative regeneration shoots and plants4 The transgenic plants were indentified by PCR amplication and GUS staining.