中文摘要：

为评价十溴联苯醚（BDE-209）对植物的生态毒性效应，探明植物抵抗BDE-209胁迫的反应机制，文章选用紫花苜蓿作为受试植物，考察了不同浓度BDE-209污染土壤对紫花苜蓿种子萌发及幼苗生长的影响，并对幼苗体内的抗氧化酶活性（PDD、CAT、SOD）及可溶性蛋白质（SP）对污染物胁迫的响应进行了研究，同时还对植株的根、叶片进行扫描电镜观察。结果表明，BDE-209胁迫处理与各项生长指标呈显著负相关，抑制作用强度依次为根长〉鲜重〉芽长〉发芽率。植株体内的抗氧化酶活性和可溶性蛋白含量随污染物浓度的增加不断上升，符合线性关系，POD、CAT、SOD的活性最大可高达对照的3倍、1．77倍和2．81倍，可溶性蛋白含量可达到对照的1．89倍。扫描电镜结果显示，随着污染物浓度的提高，植物根部发根增多，叶片上气孔密度增大，气孔开度变小。

英文摘要：

To evaluate the toxicity of decabromodiphenyl ether （BDE-209） on plant and ascertain the mechanism of plant resisting BDE-209 stress, Medicago sativa was selected as the test plant and effects of BDE-209 with different concentrations on seed germination, seeding growth, activities of antioxidant enzymes （POD, CAT, SOD）, and soluble protein （SP） in Medicago sativa seedlings were investigated, and morphology of the root and leaves were observed with scanning electron microscope （SEM）. Results showed that BDE-209 treatment had great negative correlation with the plant growth performance, followed the order of root length, fresh weight, shoot length, seed germination. Activities of antioxidant enzymes and SP were remarkably increased as the concentration of pollutant increased which accorded with linear model. Activity of POD, CAT and SOD was 3, 1.77 and 2.81 times of the control respectively, while SP was 1.89 times of the control. SEM indicated that hairy root and density of stoma on the leaves all increased, but stomata aperture decreased contrarily.