摘要
采用水培法,研究重金属铅和镉及其复合胁迫对溪荪(Iris sanguine)生理特性的影响。结果表明,在500mg/L铅和500mg/L铅+25 mg/L镉复合胁迫下,溪荪的叶绿素a、叶绿素b和类胡萝卜素含量增加,其中,叶绿素a含量增加显著(p<0.05);在25 mg/L镉胁迫下,溪荪的叶绿素a、叶绿素b和类胡萝卜素含量均减少,其中叶绿素a含量减少显著(p<0.05);25 mg/L镉胁迫增大了溪荪地上部分细胞膜的透性,比对照升高了27%,并使丙二醛含量增加到对照的1.19倍;在500mg/L铅胁迫下,丙二醛含量有所上升,但与对照相比差异不显著,说明在该实验浓度下,溪荪对铅的耐性比对镉的耐性强;在500mg/L铅+25 mg/L镉复合胁迫下,无论溪荪地上部分(叶片)还是地下部分(根茎和根)的丙二醛含量都明显增加,说明复合胁迫给溪荪细胞膜带来很大的伤害;铅和镉胁迫对溪荪过氧化物酶(POD)和超氧化物歧化酶(SOD)活性的影响相似,所有污染处理都对溪荪的地下部分酶活性起明显的促进作用,而对溪荪地上部分的酶活性有明显抑制作用。过氧化物酶和超氧化物歧化酶活性在溪荪耐铅和镉胁迫中起到了非常重要的作用。
A hydroponics experiment was conducted to examine the effects of lead,cadmium and their combination pollution on the physiological property of Iris sanguinea.The results obtained after lead and cadmium treatments for 8 days showed that the contents of chlorophyll a,chlorophyll b and carotenoid in the leaves of I.sanguinea were increased and the contents of chlorophyll a were significantly increased（p0.05）under 500 mg/L lead,and 500 mg/L lead＋25 mg/L cadmium pollution.The contents of chlorophyll a,chlorophyll b and carotenoid were decreased under 25 mg/L cadmium pollution and the content of chlorophyll a was significantly dropped（p0.05）.The relative electric conductivity of the cell membrane in the leaves of I,sanguinea under the pollution of 25 mg/L cadmium was significantly increased by 27%compared with that of control. Malonaldehyde（MDA）content in the leaves under the stress of 25 mg/L cadmium was significantly increased to 1.19 times of the control.MDA contents in the leaves and rhizomes and roots was not increased insignificantly under 500 mg/L lead stress,indicating that I.sanguinea has a better resistance to lead than cadmium in the experimental concentrations.MDA content in the leaves and rhizomes and roots under the pollution of 500 mg/L lead＋25 mg/L cadmium was significantly increased,which indicated that the cell membrane was damaged by combination of lead and cadmium pollution.The pollution of lead and cadmium and their combination had a similar effect on superoxide dismutase and peroxidase activities of I.sanguinea.The activities of superoxide dismutase and peroxidase in the rhizomes and roots were enhanced compared with that of control of no pollution and those in the leaves were decreased.The activity of superoxide dismutase in the rhizomes and roots under the pollution of 25 mg/L cadmium was significantly increased.The activity of peroxidase in the rhizomes and roots under all treatments of lead and cadmium were significantly increased.
出处
《湿地科学》
CSCD
2011年第2期198-202,共5页
Wetland Science
基金
国家自然科学基金项目(30771520)
江西省自然科学基金项目(2008GZN0064)
国家大学生创新项目(101042136
101042137)资助
关键词
溪荪
铅
镉
生理指标
Iris sanguinea
lead
cadmium
physiological index
