缺钼对黄瓜幼苗耐冷性的影响及其与抗氧化系统的关系

为了探讨缺钼对黄瓜幼苗耐冷性的影响机理,以津优3号黄瓜幼苗为试材,设置缺钼(-Mo)和施钼(CK)2个处理,在光照培养箱内进行低温(昼/夜温度为8℃/5℃)处理,研究缺钼(-Mo)对黄瓜幼苗冷害指数、MDA含量、抗氧化酶活性及渗透调节物质含量的影响。结果表明,低温下-Mo处理黄瓜幼苗叶片的电解质渗漏率(EL)、冷害指数和丙二醛(MDA)含量均显著高于CK,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性及谷胱甘肽(GSH)和抗坏血酸(AsA)含量显著低于CK,脯氨酸、可溶性糖、可溶性蛋白质和游离氨基酸含量也低于CK。可见,缺钼加重了低温对细胞膜的伤害,降低了黄瓜幼苗的耐冷性;抗氧化能力和渗透调节能力下降是缺钼引起黄瓜幼苗耐冷性减弱的重要原因。

Effects of Molybdenum Deficiency on Cold Resistance and Its Relationship with Antioxidant System in Cucumber Seedlings

In order to investigate the mechanism of molybdenum deficiency on chilling tolerance in cucumber（ Cucumis sativus L.） seedlings，this paper takes‘Jinyou No.3’ cucumber seedlings as test material，and sets up 2 treatments：molybdenum deficiency（-Mo） and molybdenum application（CK）. The low temperature treatment （day/night temperature of 8 ℃ /5 ℃） was carried out in light growth chamber. The effects of molybdenum deficiency on chilling injury index，MDA content，antioxidant enzyme activities，and osmoregulation substances of cucumber seedlings were studied. The results showed that under low temperature -Mo treatment，the electrolyte leakage（EL），chilling injury index，and MDA content of cucumber seedlings were all significantly higher than that of the CK；while the activities of superoxide dismutase（SOD），peroxidase（POD），catalase（CAT） and ascorbate peroxidase（APX），and contents of glutathione（GSH），and ascorbic acid（AsA） in cucumber seedlings were significantly lower than that of the CK. The contents of proline，soluble sugar，soluble protein and free amino acids were all lower than that of the control. These results suggest that molybdenum deficiency aggravates chilling damage to the membrane，and reduces the cold resistance of cucumber seedlings. The reduction in antioxidant abilities and osmotic self-regulation of -Motreatment are the important reasons for cold tolerance weakening of cucumber seedlings.