中文摘要：

采用营养液水培，研究了根际低氧胁迫下Ca^2＋对两个耐低氧能力不同的黄瓜品种根系呼吸代谢的影响。结果表明：与耐低氧能力较弱的‘中农8号’相比，耐低氧能力较强的‘绿霸春4号’根系LDH活性增加幅度较低，乳酸含量较少，ADH活性增加幅度较大，SDH和IDH活性降低幅度较小。低氧胁迫下，营养液加钙处理能够提高根系SDH、IDH和ADH活性，降低LDH活性和乳酸含量；而低氧缺钙处理表现出相反的结果。这表明，低氧胁迫下，Ca^2＋能提高根系乙醇发酵能力，降低乳酸发酵，使植物保持有氧呼吸代谢，从而缓解低氧胁迫对植株的伤害。

英文摘要：

The effect of Ca^2＋ on respiratory metabolism in two cucumber cuhivars （ Cucumis sativus L. ） ‘ Zhongnong 8＇ （ the hypoxia-sensitive cuhivar） and ‘Lübachun 4＇ （ the hypoxia-tolerant cuhivar） seedling roots was investigated under hypoxia stress in nutrient solution. The results showed that compared with‘ Zhongnong 8＇ seedling roots, the decrease of activities of succinic dehydrogenase （SDH） and isocitric dehydrogenase （IDH） was weaker and the increase of alcohol dehydrogenase （ADH） activity was greater, the increase of lactate dehydrogenase （LDH） activity was weaker, and lactate content was lower in seedling roots. The activities of SDH, IDH and ADH were promoted, while LDH activity was accumulation of lactate was depleted in cucumber seedling‘Lübachun 4＇ inhibited, the roots under the calcium sufficient hypoxic treatment, but that showed inverse results under the calcium deficient hypoxic treatment. The results suggested that exogenous calcium could increase the capacity mentation and maintain aerobic respiration for resistance to hypoxia stress for cucumber of ethanol fermentation and decrease the capacity of lactate fercucumber seedling roots, which was beneficial to improve the seedlings