镉胁迫下增施氮对杨树生长和光合特性的影响

Effects of Nitrogen Supplement on Photosynthetic Characteristic and Growth rate of Poplar Plants Under Cadmium Stress

为探讨植物对重金属镉的解毒机制,本实验以"欧美107杨"扦插苗为材料,以CdCl2和Cd(NO3)2为镉源,研究了在镉处理下施加氮肥(NH4HCO3)对其的生长和光合特性的影响。结果表明,在硝酸镉或氯化镉胁迫下,施用碳酸氢铵能缓解重金属镉对杨树植株的危害,其生长,叶绿素含量和光合速率显著高于对照。单独的氯化镉胁迫处理抑制杨树生长,杨树叶色黄化,叶绿素含量和光合速率降低。由此说明,氮在植物对重金属镉的解毒中起到重要作用,增施氮肥可缓解镉对植物的毒害,提高叶绿素含量和光合速率。

In order to investigate the mechanism of plant detoxification against heavy metal,this study was made on the effects of CdCl2,Cd（NO3）2 and CdCl2＋NH4HCO3 stresses on growth and photosynthetic characteristic of poplar plants by selecting the cutting poplar plants ＂107＂ as the experimental materials and using CdCl2 and Cd（NO3）2 to stress the poplar plants.The results showed that application of Cd（NO3）2 or CdCl2 by adding NH4HCO3 to the poplar culture soil could relieve the toxicity of cadmium to plants,and the growth of poplar plants,the content of chlorophyll a（Chl a） and chlorophyll b（Chl b）,as well as photosynthesis,were significantly higher than those of the control.However,the addition of CdCl2 to the soil inhibited the growth of poplar plants and led to a decrease in photosynthetic pigment content and photosynthesis.It can be concluded that nitrogen plays an important physiological role in detoxifying plants from heavy metals,that addition of nitrogen can alleviate the toxicity of cadmium to plants,increase the content of chlorophyll and photosynthesis,and stimulate the growth of poplar plants.