铅胁迫对金盏银盘生长及生理生化的影响

Effects of Lead Stress on Growth,Physiological and Biochemical of Bidens Biternata

通过水培模拟试验，研究不同处理时间和不同浓度铅胁迫下金盏银盘生物量及生理生化指标。结果表明，低浓度铅对金盏银盘生长有促进、高浓度有抑制作用；低浓度铅处理（Pb^2＋≤20mg／L）对叶绿素合成有促进、高浓度抑制作用，而随处理时间的延长，各处理浓度最终均引起叶绿素含量的下降；在铅胁迫处理2～8d内，各浓度处理脯氨酸含量都高于对照，在处理10～12d内，低浓度铅处理（Pb^2＋≤10mg／L）脯氨酸含量高于对照，随处理时间的延长变化不规律；在铅胁迫12d内，丙二醛含量基本均随着铅浓度的升高而增加，且均高于对照，随时间增加表现为先升高后降低再升高的趋势；在铅处理8d内，POD活性随着铅浓度的增加基本表现为先升高后降低再升高的趋势，而在处理8d后，基本表现为先降低后升高的趋势；铅胁迫对SOD活性有一定抑制作用，各铅浓度处理在相同处理时间对SOD活性的抑制无明显的规律。POD活性波动较大，而SQD活性最终都会增加。

Through hydroponics simulation experiment ,we study the growth of Bidens biternata under different time of treatment and different stress of Lead concentration, and also obtain the physiological and biochemical index which includes content of Chlorophyll. free praline. MDA and the change of POD.SOD protective enzymes activity. The results show that： when Lead concentration of treatment is 5.10 mg/L low-concentration, it plays a catalytic role on the growth of Bidens biternata, high-concentration has the opposite effect; The Lead treatment of low concentration （Pb^2＋≤420 mg/L）has an catalytic effect on Synthesis of Chlorophyll; when Lead stress in the 2-8 d, praline content under the treatment of concentration is higher than the control, when in the 10-12 d, praline content under low concentration of Lead （Pb^2＋≤10 mg/L）is also higher than the control; When Lead stress under 12 d, content of MDA increases along with higher Lead concentration which is higher than the control; POD performs the trend of fist low then rise in the 8 d of Lead concentration. Lead stress has an effect of inhibition on the activity of Bidens biternata leaf＇s SOD, each treatment of Lead concentration cannot regulate the effect of inhibition on SOD＇s activity in the same processing time. with the extension of the processing time, each treatment of concentration will eventually cause the decline of chlorophyll content; praline content with the extension of the processing time there is a irregular change; MDA with the extension of the processing it performs first rise then lower in the trend of rise; the activity of POD with a larger fluctuation, but the activity of SOD will eventually increase.