Identification of soft rot pathogens on Chinese cabbage［Brassica campestris L．ssp．chinensis(L．) Makino var．communis Tsen et Lee］in Beijing

Abstract:

Abstract:［Objective］This study aimed to identify soft rot pathogens of Chinese cabbage ［Brassica campestris L. ssp．chinensis (L.) Makino var． communis Tsen et Lee］in Beijing.［Methods］The 40 strains isolated from Tongzhou and Daxing districts in Beijing were characterized by morphological，biological，biochemical and physiological methods，16S rRNA sequence as well as 16S-23S rRNA intergenic spacer (IGS) region analysis.［Results］The strains belonged to two different Pectobacterium carotovorum subspecies: 13 strains of them belonged to Pectobacterium carotovorum subsp．carotovorum (Pcc) and the other 27 strains belonged to Pectobacterium carotovorum subsp． brasiliensis (Pcb). The results of Chinese cabbage (Brassica campestris L. ssp．pekinensis) pathogenicity test showed that the strains in the same subspecies，origins and 16S rRNA gene sequences had significant differences in pathogenicity.［Conclusion］Pectobacterium carotovorum subsp． carotovorum and Pectobacterium carotovorum subsp．brasiliensis were the soft rot pathogens on Chinese cabbage ［Brassica campestris L. ssp．chinensis(L.)Makino var． communis Tsen et Lee］in Beijing．It was the first report that Pectobacterium carotovorum subsp． brasiliensis (Pcb) caused soft rot disease on cabbage in China．

Key words:Keywords: Brassica campestris L. ssp．chinensis (L.) Makino var．communis Tsen et Lee，soft rot disease，Pectobacterium carotovorum subsp． carotovorum (Pcc)， Pectobacterium carotovorum subsp．brasiliensis (Pcb)，pathogenicity