中文摘要：

用20mmol·L^-1氯化钙（CaCl2）、醋酸钙（CaAc2）和硝酸钙（Ca（NO3）2）喷施“国庆1号”温州蜜柑叶片，研究3种钙盐对其叶片抗冻性的影响．结果表明：喷施钙盐降低了叶片半致死温度（LT50），提高了温州蜜柑的抗冻性，CaCl2处理的LT50比对照降低了0．54℃，而CaAc2和Ca（NO3）2处理分别比对照降低了1．34℃和1．35℃，表明CaCl2处理效果较差，CaAc2和Ca（NO3），处理效果较好．钙盐处理还提高了“国庆1号”温州蜜柑叶片在低温（-9℃）胁迫下的SOD、POD活性及可溶性蛋白质、可溶性糖和脯氨酸含量，减少了叶片MDA的积累．

英文摘要：

The study on the effects of foliar spraying 20 mmol · L^-1 of CaCl2, Ca（ NO3 ）2 and CaAc2 on the freezing resistance of satsuma mandarin （ Citrus unshiu Marc. cv. Guoqing No. 1 ） showed that after treated with these Ca salts, the leaves of test plant had a lower half lethal temperature （LT50） than the control （sprayed with distilled water）. The LT50 after treated with CaCl2 was 0.54 ℃ lower, whereas that after treated with CaAc2 and Ca（ NO3 ） 2 was 1.34 ℃ and 1.35 ℃ lower, respectively, implying that the latter two Ca salts were more effective in enhancing the freezing resistance of satsuma mandarin. Moreover, foliar spraying Ca salts increased the superoxidase （SOD） and peroxidase （POD） activities and the contents of soluble proteins, soluble sugars and praline in leaves, and decreased the leaf MDA content.