Abstract: The gourd rootstock and watermelon were planted hydroponically to investigate the effect of anaerobic environment on antioxidant enzymes and metabolites. The results indicated that root activity of gourd rootstock and watermelon both decreased under hypoxia stress, and activities of ADH, SOD, APX, proline content firstly increased and then decreased. The variation range of antioxidant enzymes in gourd rootstock was greater than in watermelon. Moreover, gourd rootstock contained higher content of MDA than watermelon during treatment time. But anaerobic environment could not affect the activity of CAT in rootstock and watermelon．

Key words: watermelon, gourd rootstock, hypoxia stress, physiological characters