Abstract: The soft rot infected by pathogenic bacterium Erwinia aroideae Holland is one of the three serious diseases of Chinese cabbage (Brassica pekinensis Rupr.). By constructing vector system of high frequency transformation mediated by Agrobacterium tumefaciens EHA105, anti bacterial peptide gene with strong bactericidal action to pathogenic bacteria was introduced into Chinese cabbage AB 81 self bred line and the transgenic plants were obtained. PCR and Southern blotting detection showed that target gene was integrated into plant genome of Chinese cabbage. The tests of bacteriostasis action of the extract from transgenic plants in vitro, and the assay of disease resistant of transgenic plantlets in the tube and the pot by perfusing inoculation with pathogenic bacteria showed obvious resistance to soft rot. This resistance can be a stable heredity by genetic analysis of generations of transgenic plants self bred, separation ratio of its R1 was 3∶1. The resistance to Km and disease of soft rot was still kept in the R5. These results indicated the possibility of breeding new varieties of anti soft rot Chinese cabbage by transgenic plants as parents.

Key words: Brassica pekinensis, antibacterial peptide gene, transformation, softrot