Abstract: The effects of flooding stress on aboveground growth and physiological characteristics of Chinese cabbage （Brassicacampestris ssp.chinensis L.） seedlings were studied by using a two-factor randomized block design. The results showed that the above ground fresh weight and dry weight of four Chinese cabbage varieties were significantly lower than the control at 10 and 15 days after waterlogging, indicating that the above ground growth of Chinese cabbage was inhibited by waterlogging stress. However, the four Chinese cabbage varieties did not die after 15 days of flooding, indicating that the four Chinese cabbage varieties were relatively resistant to flooding. At 5 days, 10 days and 15 days after waterlogging, the chlorophyll content of the four Chinese cabbage varieties were significantly lower than that of the control, and the malondialdehyde content was significantly higher than that of the control, indicating that the photosynthesis of Chinese cabbage was inhibited under waterlogging stress and was damaged to a higher degree. Meanwhile, the activity of SOD, POD, CAT, PPO, APX and the content of soluble sugar, soluble protein and proline of the four Chinese cabbage varieties were significantly higher than that of the control group at 10 and 15 days after waterlogging, indicating that the four Chinese cabbage varieties could resist waterlogging stress by improving the activity of antioxidant enzymes on the one hand, and adapt to waterlogging stress by increasing the content of osmotic regulatory substances on the other hand. After 5 days of recovery, the CAT activity, MDA and proline contents of the 4 Chinese cabbage varieties were significantly lower than that after 15 days of flooding, indicating that the physiological state of Chinese cabbage was restored to some extent.

Key words: waterlogging stress, Chinese cabbage （Brassicacampestris ssp.chinensis L.） seedling, growth, physiological characteristics