中文摘要：

以耐冷性存在明显差异的栽培黄瓜‘长春密刺’和‘北京截头’为材料，研究了冷胁迫下Ca^2＋、钙离子螯合剂（EGTA）和钙调素拮抗剂（CPZ）对低温胁迫黄瓜幼苗叶片3种抗氧化酶活性及POD同工酶的影响。对保护酶活性的研究结果表明：CaCl2、EGTA和CPZ处理均能引起3种抗氧化酶活性变化，但变化幅度因材料而异。胁迫处理中Ca^2＋能提高2种材料的叶片抗氧化酶活性，减少其在低温逆境中的下降幅度，而EGTA和CPZ处理降低了2种材料的抗氧化酶活性，加大了低温逆境中的下降幅度。POD同工酶研究发现，CaCl2延缓冷胁迫中同工酶条带的丢失，EGTA和CPZ处理则使同工酶条带丢失提前，但材料不同对酶条带丢失时间也有影响。

英文摘要：

＇Changchun mici＇ and ＇Beijingjietou＇ ,two cucumber varieties remarkably differing in cold tolerance, were used to study the effects of Ca^2＋ , EGTA, a Ca^2＋ chelator,CPZ,a Calmodulin antagonist, on the activities of three anti-oxidative enzymes and POD isoenzymmes in the leaves of young cucumber seedlings suffering low-temperature stress. The results about the activities of the anti-oxidative enzymes indicated that all the treatments with CaCl2,EGTA and CPZ could cause the activities of the three enzymes to vary depending on the varieties. In the stress treatments ,Ca^2＋ was capable of increasing the activities of the antioxidative enzymes in the two varieties and thus decreasing the activity decrements of the enzymes but EGTA and CPZ were capable of lowering the activities of the anti-oxidative enzymes in the two varieties and thus enlarging the activity decrements of the enzymes. The results about POD isoenzymes indicated that under chilling stress ,CaCl2 could delay the loss of the spectral bands of the isoenzyme and EGTA and CPZ advanced the loss of the spectral bands of the isoenzyme but when did the loss of the spectral band occurred depended on the varieties.