外源Ca2+对藏药独一味幼苗速冷冻抗性的效应

 利用不同浓度CaCl₂喷施独一味两对叶龄幼苗,然后分别迅速置不同低温（4 ℃、0 ℃和-4 ℃）处理48 h,以28 ℃为对照,处理结束测定幼苗叶片叶绿素含量、细胞膜稳态性、抗氧化酶活性和膜质过氧化等指标的变化,旨在揭示外源Ca2+对提高独一味幼苗速冷冻抗性的作用效应,为独一味人工驯化栽培提供理论依据。结果表明,独一味幼苗对0 ℃及以上低温速冷冻表现较强的适应性。喷施15 mmol\5L-1的CaCl2能显著诱导增强独一味幼苗叶中SOD、POD活性,降低膜质过氧化程度,增强细胞膜系统的稳定性,有效改善独一味幼苗的速冷冻抗性,缓解速冷冻胁迫对幼苗的伤害,使叶绿素含量维持在较高水平,为适宜条件下迅速恢复生长奠定了良好基础。

Effects of Exogenous Ca2+ on Resistance to Rapid Cold and Freeze of Tebet Lamiophlomis rotate (Benth.) Kudo Seedlings

The seedlings of Tebet Lamiophlomis rotate (Benth.) Kudo at two-pair-leaf age were sprayed with different concentrations of CaCl2, and then were rapidly exposed to different low temperatures (4 ℃, 0 ℃ and -4 ℃) for 48 hours. Simultaneously, the treatment in 28 ℃ was taken as the Check. 48 hours later, the seedlings relative conductivity, chlorophyll content, MDA content, SOD and POD activities in the leaves were measured so as to explore the effect of exogenous Ca2+ on their resistance to rapid cold and freeze and provide a theoretical basis for their artificially domestic cultivation. The result indicated that the seedlings are well adapted to low temperatures at and above 0 ℃. The CaCl2 in concentration of 15 mmol\5L-1 can significantly motivate antioxidant enzymes such as SOD and POD activities, which consequently mitigate the membrane lipid peroxidation and enhance the stability of the membrane systems. All these effectually enhance the cold resistance of Tebet L. rotate, reduce the injury caused by rapid cold and freeze, and keep higher chlorophyll content in leaves to lay a good foundation for regrowth under good environmental condition.