马占相思树苗对低温冻害的抗性研究

Study on the resistance of Acacia mangium to low temperature stress

以盆栽马占相思PNG17868家系树苗为材料,研究了低温胁迫下树苗生长发育有关的生理生化指标的变化及其抗冻害的关系。结果表明:随着低温胁迫程度的加深和时间延长,植株细胞电导率显著升高,细胞膜ATPase活性呈下降趋势,而可溶性糖、脯氨酸和可溶性蛋白质含量亦不断升高,表现出耐寒植物较典型的生理特点,说明该植物有明显的渗透调节能力和抗寒性。在零下低温(0～6℃)胁迫下,植物细胞防御系统的保护酶类(CAT、POD、SOD)的活性先是升高,然后有所下降,但下降幅度不大。这表明了马占相思PNG17868家系对低温有较强的适应能力,在温度日益降低(0～6℃)条件下体内保护酶仍能维持较高的活性水平,减轻了由膜脂过氧化引起的膜伤害,是植物提高抗寒性、免遭低温冻害的重要原因。

The relationship between the anti-chilling ability of the plants and their physiological changes was studied in Acacia mangium PNG17868 clone suffered from temperature changes from 12 ℃ to -6 ℃. The results showed that the electrical conductivity of the cells increased obviously, and the actibity of ATPase reduced. At the same time,the content of soluble sugar,praline and soluble protein increased. Under the temperature of 0-6 ℃, the activities of the protective enzymes, i. e. catalase（CAT）, peroxidase（POD）, and superoxidase（SOD）,increased firstly and then decreased slightly. However, they still sustained in a relatively high level. This indicated that the plants of Acacia rnangiurn PNG17868 clone had a relatively high adaptivity to cold stress.