Influence of Low Temperature Stress to Cold Resistance and Physiological Indicators of Watermelon Grafted Seedlings

Screened two stocks with cold resistance.The grafted seedlings have low injury index and low electrolytic leakage after low temperature stress.Compared to contrast seedlings,the protein contents of the grafted seedlings increased significantly.The contents of MDA were enhanced after lower temperature both in grafted seedlings and contrast seedlings,and the activity of SOD and CAT were decreased,but the decreased range of grafted seedlings are lower than the contrast seedlings,and kept on an higher level.The POD activity of grafted seedlings and contrast seedlings had little difference on normal temperature,and it would increased after low temperature stress,and the increased range of grafted seedlings were higher than the contrast seedlings.So the cold resistance of grafted seedlings were better than contrast seedlings.