Effects of cold stress on activity of antioxidant enzymes and malondialdehyde content in cotton seedling | 冷胁迫对棉苗抗氧化酶活性及丙二醛含量的影响

chinois. 以早熟、中熟、晚熟3种不同熟性的5个棉花品种幼苗进行4°C冷胁迫处理, 通过分析胁迫条件下过氧化物酶 (POD) 活性、超氧化物歧化酶 (SOD) 活性和丙二醛 (MDA) 含量的变化, 比较不同棉花品种苗期抗冷性差异。结果表明, 在4°C胁迫处理的3天中, POD活性呈现先上升后下降的趋势, 冷处理第二天中熟品种N177的POD活性显著增强, 为对照的239.9%; SOD活性在处理的3天中, 都有不同程度的增加, 其中晚熟品种K-1活性变化最显著, 为对照的162.4%; 不同品种MDA含量均随着处理时间的延长而增加, 早熟品种N52增加幅度最小, 综合分析, 5个棉花品种中, 早熟品种N52抗冷性较强。

anglais. In order to analyse the effects of cold treatment on peroxidase (POD), superoxide dismutase (SOD) activity and malondialdehyde (MDA) content, in this experiment, five cotton cultivars including one precocious, two medium-and two late-mature cultivars were treated with 4°C for 0 h, 24 h, 48 h and 72 h, respectively. The results indicated that there were significant differences of POD and SOD activity and MDA content among different cotton cultivars with the extension of low-temperature stress time. At primary stage of cold stress, the POD activity exhibited an increasing trend. The POD activity was significantly increased after cold treatment in N177, about 239.9% of CK. However, at the late stage of cold stress, the POD activity significantly declined. The SOD activity gradually increased in five cotton cultivars. In particular, the SOD activity of K-1 significantly increased after cold treatment, about 162.4% of CK. The MDA content of different cultivars increased with the treatment time, but the increasing rate of precocious cultivar 52 was the lowest. Collectively, N52 had significant cold resistance.