Systematic study was carried out on the physiological changes of the wheat root system under different waterlogging duration at different growth stages from 1992 through 1994. The results indicated that waterlogging could lead to increase of the permeability of the plasma membrane and the MDA content of the root system, but decreased the respiration rate and the activity of the root system under these conditions. The activities of both SOD and POD were enhanced during the early days of waterlogging, and the...