中文摘要：

为了解一溴代联苯醚（4-monobrominated diphenyl ether,4-BDE）的植物修复机制,本文研究了不同浓度4-BDE处理对毛白杨组培苗不定根的形态、分化状况、细胞组织学以及部分生理特性的影响.发现一定浓度的4-BDE处理对毛白杨组培苗不定根的分化表现出先抑制后促进的效应,说明4-BDE可能具有一定的植物生长素生物效应.在4-BDE的诱导处理下,组培苗不定根的颜色变深,300 mg·L~（-1）时根呈黑褐色且受到明显的伸长抑制,但并未坏死.与对照苗相比,4-BDE诱导处理的毛白杨组培苗不定根的显微结构发生明显变化,表现为根皮层细胞内含物增多,皮层细胞排列变紧密.高浓度30 mg·L~（-1）4-BDE处理23 d的组培苗不定根丙二醛（MDA）含量显著高于处理47 d和58 d的（P〈0.05）;相同处理时间30 mg·L~（-1）4-BDE处理的过氧化物酶（POD）活性显著高于对照组（P〈0.05）.随着处理时间的延长,3 mg·L~（-1）4-BDE处理的组培苗不定根的MDA含量呈现先上升后下降的趋势,POD活性呈逐渐上升的趋势.以上结果初步显示,毛白杨组培苗不定根对4-BDE胁迫具有一定的适应能力.

英文摘要：

In order to understand the mechanisms of phytoremediation of 4-BDE（4-monobrominated diphenyl ether）,the effects of 4-BDE on adventitious roots differentiation,phytocytohistology and some physiological-biochemical characteristics on tissue culture plantlet of Populus tomentosa were investigated. The results showed that 4-BDE promoted the differentiation of adventitious roots after an initial inhibition in a certain concentration range,which indicated that 4-BDE might have a certain biological effect on plant growth hormone. The adventitious roots under the exposure of 4-BDE became dark in color in comparison with the control,and 300 mg·L-14-BDE had a remarkable restraining effect on the length of adventitious roots. Compared with the control,the microstructure of adventitious roots treated with 4-BDE changed significantly. The cellular contents within adventitious roots increased and the cortical cells became closely arranged. In addition,for 30 mg·L-14-BDEtreatment,MDA（Malondialdehyde） content of adventitious roots on 23 th day was significantly higher than the content on 47 th day and 58 th day（P〈 0. 05）; For the same treatment time,POD（Peroxidase） activity in adventitious roots under 30 mg·L-14-BDE treatment was higher than that of the control（P 〈0. 05）. Under 3 mg·L-14-BDE treatment,the MDA content first increased with treatment time and then decreased,while POD activity presented a gradually increasing trend. These results showed that the adventitious roots of tissue culture plantlet of P. tomentosa had a certain adaptability to 4-BDE stress.