Isolation and Identification of a Bacterial Agent Causing Soft Rot in Chinese Cabbage

The Chinese cabbage (Brassica rapa subsp. pekinensis), part of the Brassicaceae family, is a biennial plant that has long been cultivated in China and East Asia. However, various plant diseases cause considerable damage to Chinese cabbage yields during cultivation. In this study, diseased Chinese cabbages that showed typical symptoms of bacterial soft rot were collected from different fields in Poheon, Gyeonggi-do, South Korea from September to October in 2019. The causal agent was isolated from the cabbage samples and subsequently re-inoculated into healthy cabbage tissues. The re-inoculated healthy cabbages showed the same symptoms as the diseased cabbages, from which the pathogen was originally isolated. The isolated pathogen was identified as a member of the genus Pseudomonas using 16S rRNA analysis. This result may suggest that a Pseudomonas species isolated from the cabbage can be the causal agent of soft rot that are currently spread in Pocheon, Korea. Further research for accurate identification of the bacterial species should be needed.