低温胁迫对嫁接西瓜幼苗耐冷性和生理生化指标的影响

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

筛选出西瓜嫁接耐冷砧木2份。低温胁迫后嫁接苗叶片冷害指数小,电解质渗透率低;嫁接苗比自根苗叶片的水溶性糖和水溶性蛋白含量升高明显高;随着低温胁迫天数的增加,嫁接及实生西瓜幼苗叶片MDA含量均呈上升趋势,但随着低温时间的延长,SOD活性呈下降趋势;CAT活性总体呈下降趋势,嫁接苗下降幅度较小,且维持在一个较高水平;正常光温下生长的西瓜嫁接苗和自根苗的POD活性无明显差异,低温处理后POD活性总体呈上升趋势,嫁接苗上升幅度较快,可见,嫁接苗的耐冷能力强于自根苗。

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.