干旱胁迫对黄檗幼苗生理及叶片中小檗碱含量的影响

以黄檗幼苗为实验材料，采用3种浓度的聚乙二醇(PEG 8000)模拟干旱胁迫，研究黄檗幼苗的生理适应特征和叶中小檗碱含量的变化。结果表明:在5%、10%和20%的PEG胁迫下，丙二醛（MDA）含量变化各异。在5% PEG胁迫处理下，MDA含量不但没有增加，反而减少，而且在整个胁迫进程中一直低于胁迫前的水平（P0.05），在10% PEG处理下，MDA的含量较处理前有所增加，但增加量也较少，只是在处理9 h时才有明显增加（P0.05），20% PEG胁迫处理下，MDA含量呈单峰曲线；质膜透性都随胁迫时间变化呈波动上升趋势，PEG浓度越大对膜伤害程度越大；脯氨酸含量都是先降低后上升，高浓度变化幅度较大；SOD活性都是先升高后降低，PEG浓度越高变化幅度越大，活性高峰出现的时间越早；叶片中小檗碱的含量随胁迫时间先升高后降低，高浓度含量高峰出现时间较早，低浓度含量高峰出现时间较晚，但含量最大值较高。 

Influence of drought stress on plant physiology and berberine content of leaves in Phellodendron amurense seedlings

The physiological tolerance adaptation characteristics and the changes of berberine content in leaves of Phellodendron amurense seedlings were investigated under the simulated condition of drought using three different concentrations of polyethylene glycol (PEG 8000). The results showed that the contents of MDA in P. amurense seedlings under 5%, 10% and 20% PEG were different. Under the 5% PEG stress, MDA content reduced, and in the entire stress process were lower than that before treatment (P<0.05). Under the 10% PEG stress, MDA content increased a little and a significantly increase appeared at the 9th hour (P<0.05). MDA content showed a single peak curve under the 20% PEG stress. Membrane electrolyte leakage in leaves showed a fluctuated upward trend with the stress time, and the higher concentration of PEG damaged membrane more seriously. The content of proline decreased firstly, and then increased. Under higher concentrations of PEG, the proline content varied greatly. The activity of SOD increased firstly, and then decreased. With the increase of PEG concentration, the SOD activity peaks came earlier. Berberine content in the leaves increased at the beginning, and then decreased gradually with the increase of duration. Under higher concentration of PEG, the berberine content reached its peak earlier, while under lower concentration of PEG, the berberin content peak came later but the maximum value was higher.