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作 者 ：胡春梅;季俊杰;王秀峰*;朱月林

期 刊 ：植物研究 2006年 26卷 6期 页码：685-690

关键词：瓜尔豆幼苗；低温；SOD；POD；MDA；

Keywords:guar seedling, low temperature, SOD, POD, MDA,

摘 要 ：通过温室穴盘育苗试验，研究叶面喷施(NH₄)₂SO₄对低温胁迫12 h后不同光通量密度（PFD）条件下，瓜尔豆幼苗在常温培养过程中幼苗生存及叶片SOD活性、POD活性和MDA含量的影响。结果表明：低温处理一夜后，在温室自然光照（强光）下进行常温恢复时，瓜尔豆叶片中SOD和POD活性始终显著低于对照，MDA含量显著高于对照，幼苗死亡率显著高于对照；在90 μmol·m^-2·s^-1弱光下恢复2～4 d后，叶片中保护酶活性显著高于对照，MDA含量保持较低水平，幼苗均正常生长。叶面喷施(NH₄)₂SO₄能显著提高低温处理后的植株叶片抗氧化酶类活性，减少叶片中MDA的产生，降低幼苗死亡率，0.2% (NH₄)₂SO₄处理效果最好，其次为0.4%(NH₄)₂SO₄。短期低温后，使植物处在弱光环境下能减少活性氧的发生，为植物抗氧化系统达到新的平衡提供有利条件，从而减轻甚至消除低温伤害。

Abstract:Guar seedlings were grown in greenhouse, and effects of leaf spray (NH₄)₂SO₄ on changes of superoxide dismutase (SOD), peroxidase (POD) activities and malondialdehyde (MDA) content in leaves and death rate of seedlings were studied in different photon flux densities (PDF) after chilling 12 hours at 2±0.5℃. The results showed, SOD and POD activities were lower, MDA content was higher, and death rate of seedlings was higher in the treatment recovered under normal sunlight in greenhouse than those of the control. When the seedlings were recovered under 90 μmol·m^-2·s^-1 weak light for 2~4 days, SOD and POD activities were higher than those of the control, MDA content kept at a low level, and seedlings were survived normally. Application of (NH₄)₂SO₄ increased protective enzyme activities, reduced MDA content in leaves during recovery time after chilling 12 hours, improved seedling resistance to low temperature, and significantly decreased the death rate of guar seedlings. The effect is the best for seedlings sprayed with 0.2% (NH₄)₂SO₄, followed by 0.4% (NH₄)₂SO₄. If weak light is given to seedlings after a short-term chilling, active oxygen species would be reduced and chilling injury could be alleviated or even eliminated.

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