镉对龙葵(Solanum nigrum L．)根系形态及部分生理指标的影响  

Effect of cadmium on root morphology and partial physiological indexes of Solanum Nigrum L.

作　　者：唐秀梅[1] 龚春风[1] 周主贵[2] 刘鹏[1] 徐根娣[1] 蔡妙珍[1] 吴琼鸯[1] 

机构地区：[1]浙江师范大学植物学实验室 [2]广西农科院,广西南宁530004

出　　处：《生态环境》2008年第4期1462-1465,共4页Ecology and Environmnet

基　　金：国家自然科学基金项目(30540056);浙江省自然科学基金项目(303461)

摘　　要：以龙葵（Solanum nigrum L）为材料，水培法设置了5个镉质量浓度：0、10、25、50、100mg·L^-1进行试验。在处理17d和34d时，分别对其根系形态和部分生理指标进行测定。结果表明：（1）中低质量浓度（10～50mg·L^-1）的镉促进龙葵根系生长，表现在处理17d时其根长、体积均随镉质量浓度升高而增加；高质量浓度（100mg·L^-1）的镉抑制根系生长，表现在处理34d时其根长、体积、直径低于对照，根长达到届著水平。随着镉处理时间的延长，10mg·L^-1促进效果明品，表现为处理34d时其根长、体积、直径均达到最大值，100mg·L^-1抑制程度加剧，表现为其根长、体积、直径均急剧下降；（2）0～50mg·L^-1的Pro含量和质膜透性与对照相比差异不显著，100mg·L^-1 MDA与Pro含量均冠著高于对照，100mg·L^-1的质膜透性在处理34d时比对照增加了58．7％。说明高质量浓度镉使龙葵积累了大量的MDA和Pro，对龙葵表现出毒害作用，而龙葵作为超积累植物对镉胁迫表现出一定的耐性与适应性。Large areas of cultivated land in many countries have been contaminated by Cd due to agricultural and industrial practices such as application of pesticides and chemical fertilizers, waste water irrigation, precipitation from heavy coal combustion, and smelter wastes and residues from metalliferous mining. As a newly diacovered Cd- hyperaccumulator, Solanum nigrum L. has enough advantages such as the low condition of growth, the fast growing and the high biomass. So it is necessary to further study the mechanism of cadmium tolerance and accumulation. In this research, the root morphology and the leaf physiology of S. nigrum were studied after 17 and 34 days exposure of Cd^2＋ （0, 10, 25, 50, and 100 mg·L^-1） in hydroponic culture, The results throughout the paper were summarized as follows： （1） The growth of root were facilitated at low concentration of Cd^2＋ 00-50 mg·L^-1） , and the root length and volume increased with the increasing of Cd^2＋ concentration. However, the length, volume and diameter of root were all lower than control at high concentration of Cd^2＋ （100 mg·L^-1）, and the root length reached significant level. With the prolonging of treating time, after 34 days with Cd^2＋ treatment, the length, volume and diameter of root reached their maximum at concentration of Cd^2＋ 10 mg.Ll, but all of them decreased sharply at concentration of Cd^2＋ 100 mg＇Ll. （2） The proline content and plasolemma permeability did not show remarkable change under low Cd^2＋ concentration （0-50 mg·L^-1）. On the contrary, MDA and Pro content of 100 mg·L^-1 were obviously higher than those of control, and plasolemma permeability increased by 58.7% compare with control. It indicated that much MDA and Pro were accumulated in Solanum nigrum L., and were poisonous for it. However, as a kind of cadmium-hyperaccumulator, S. nigrum showed resistance and adaptability to Cd stress to certain extent.

关 键 词：镉 龙葵 根系形态 生理指标 

分 类 号：X171.5[环境科学与工程—环境科学] Q945.78[生物学—植物学]