镉胁迫对金丝垂柳幼苗生长及叶绿素荧光特性的影响

Effects of cadmium stress on growth and chlorophyll fluorescence characteristics of Salix aureo pendula seedlings

关键词:  镉  金丝垂柳  光合作用  叶绿素荧光

Key words:  cadmium  Salix×aureo pendula seedlings  photosynthesis  chlorophyll fluorescence

摘要:

采用盆栽试验的方法，研究土壤中不同浓度的镉（0、2、20、80 mg•kg 1）胁迫条件对金丝垂柳幼苗的生长、净光合速率（Pn）、光合色素含量及叶绿素荧光参数（Fv/Fm、ΦPSⅡ和qP）的影响。结果表明：（1）2 mg•kg 1 处理组植物的生长、净光合速率及叶绿素荧光参数随着处理时间的增加呈先下降后上升的趋势，说明2 mg•kg 1浓度的镉对金丝垂柳幼苗影响较小。（2）20 mg•kg 1和80 mg•kg 1处理组的生长、净光合速率及叶绿素荧光参数均受到抑制，而且随处理时间的增加而表现地更明显。（3）胁迫40 d时各处理组的光合色素含量与对照相比均无显著变化，处理90 d后，其含量随镉胁迫浓度的升高呈先升高后降低的变化趋势。研究证实金丝垂柳对较低浓度（2 mg•kg 1）的镉胁迫具有良好的耐受性和和光合适应能力。

Abstract:

In order to reveal the effects of cadmium stress on the growth rate，net photosynthetic rate (Pn)，photosynthetic pigment content and chlorophyll florescence parameters (Fv/Fm，ΦPSⅡ and qP) of the young potted Salix×aureo pendula were determined. The following conclusions were approved:the growth rate，Pn and chlorophyll florescence parameters of the young Salix×aureo pendula cultured in 2 mg•kg 1 cadumium medium firstly decreased and then increased as time goes by；while they dropped dramatically with the time in 20 mg•kg 1 and 80mg•kg 1 cadmium conditioned soil media. It’s concluded that 20 mg•kg 1 and 80 mg•kg 1 but not 2 mg•kg 1 cadmium stress had significant effect on the growth of the young seeding. No changes of the photosynthetic pigment content was detected 40 days after the cadmium stress treatment. However，it increased and decreased in low and high cadmium concentration respectively 90 days after the treatments. Above all，the results suggested that the young potted Salix×aureo pendula showed the best tolerance and photosynthetic adaptability under 2 mg•kg 1 cadmium stress.