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生态学杂志 ›› 2012, Vol. 31 ›› Issue (06): 1334-1340.

• 研究报告 • 上一篇    下一篇

白三叶和红三叶对人工融冻胁迫的生理响应差异

周瑞莲**,赵梅,张萍,王艳杰,赵彦宏   

  1. (鲁东大学生命科学学院, 山东烟台 264025)
  • 出版日期:2012-06-09 发布日期:2012-06-09

Physiological differences of Trifolium repens and Trifolium pratense in response to freezingthawing stress.

ZHOU Rui-lian**, ZHAO Mei, ZHANG Ping, WANG Yan-jie, ZHAO Yan-hong   

  1. (School of Life Science, Ludong University, Yantai 264025,Shandong, China)
  • Online:2012-06-09 Published:2012-06-09

摘要: 采用人工模拟融冻胁迫方法,通过测定白三叶(Trifolium repens)和红三叶(T. pratense)在融冻胁迫中叶片细胞膜透性、MDA含量、抗氧化酶(SOD、POD、CAT)活力、渗透调节物(脯氨酸、可溶性糖和蛋白质)含量变化,以揭示未来气候变化对三叶草的影响。结果表明,经历融冻胁迫循环后抗冻力强的白三叶植株能恢复生长,而抗冻力弱的红三叶枯萎死亡。在融冻阶段,两三叶草叶片细胞膜透性增大、抗氧化酶活力增高、MDA和渗透调节物含量大幅增加;在冻融阶段,两三叶草叶片细胞膜透性降低、MDA含量下降、抗氧化酶活力降低。但在融冻胁迫循环中,白三叶叶片POD和CAT活力高于红三叶,脯氨酸含量较红三叶高5倍,但细胞膜透性低于红三叶。白三叶在-5 ℃抗逆生理指标达到最大值,而红三叶在-10 ℃。白三叶对环境温度变化反应敏感,在-5 ℃通过快速激活抗氧化酶系统和积累渗透调节物以抑制膜脂过氧化和维护细胞水分平衡在融冻适应上起重要作用。白三叶具有较强的抗融冻能力,是未来值得应用推广的优良园林绿化植物。

关键词: 双氰胺, 3, 5-二甲基吡唑, 氢醌, 氮素转化, 表观硝化率, 硝化抑制率

Abstract: A pot experiment with white clover (Trifolium repens) and red clover (T. pratense) was conducted to study their growth and physiological indices under the stress of freezing-thawing cycle, aimed to understand the effects of future climate change on the growth of clover. After the stress, white clover survived, while red clover dead. The leaf membrane permeability, MDA content, antioxidant enzymes activity, and osmoregulation substances contents of the two clovers increased in thawing-freezing phase but decreased in freezing-thaw phase. During thawing-freezing and freezing-thawing, the leaf POD and CAT activities of cold-resistant white clover were higher than those of coldsensitive red clover, the white cover’s leaf proline content was 5 times higher than red clover’s, and the leaf membrane permeability of white clover was lower than that of red clover. All the physiological indices of white clover peaked at -5 ℃ while those of red clover peaked at -10 ℃, suggesting that -5 ℃ would be a temperature point at which the physiological regulation reaction occurred to make white clover’s leaf cell adapt to ice formation and ice melting, and maintain the balance between oxygen free radicals production and scavenging. Our results suggested that white clover had higher capability to adapt to freezing-thawing cycle, and could be a good landscaping species in future application and popularization.

Key words: dicyandiamide, 3,5-dimethylpyrazole, hydroquinone, nitrogen transformation, apparent nitrification rate, nitrification inhibition rate.