College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
J Plant Physiol. 2010 Jan 15;167(2):88-94. doi: 10.1016/j.jplph.2009.07.006.
Polyploidy is reported to show increased tolerance to environmental stress. In this work, tetraploid plants of Dioscorea zingiberensis were obtained by colchicine treatment of shoots propagated in vitro. The highest tetraploid induction rate was achieved by treatment with 0.15% colchicine for 24h. Diploid and tetraploid plants were exposed to normal (28 degrees C) and high temperature (42 degrees C) for 5d during which physiological indices were measured. Compared with diploid plants, relative electrolyte leakage and contents of malondialdehyde, superoxide anions and hydrogen peroxide were lower in tetraploids, while activities of antioxidant enzymes, such as superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and glutathione reductase, were stimulated and antioxidants (ascorbic acid and glutathione) were maintained at high concentrations. These results indicate that tetraploid plants possess a stronger antioxidant defense system and increased heat tolerance.
多倍体被报道显示出对环境胁迫的耐受性增加。在这项工作中，通过秋水仙素处理体外繁殖的茎，获得了盾叶薯蓣的四倍体植物。用 0.15%的秋水仙素处理 24 小时，获得了最高的四倍体诱导率。在 5 天的时间里，将二倍体和四倍体植物分别暴露在正常（28 摄氏度）和高温（42 摄氏度）下，在此期间测量生理指标。与二倍体植物相比，四倍体植物的相对电解质渗漏率以及丙二醛、超氧阴离子和过氧化氢的含量较低，而超氧化物歧化酶、过氧化物酶、过氧化氢酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶等抗氧化酶的活性被刺激，抗氧化剂（抗坏血酸和谷胱甘肽）保持在高浓度。这些结果表明，四倍体植物具有更强的抗氧化防御系统和提高的耐热性。
