摘要
以2种耐性不同的鸢尾属植物马蔺(Iris lactea var.chinensis)和鸢尾(Iris tectorum)为试材,通过营养液培养法,研究了Cd胁迫对其幼苗生长、Cd积累及微量元素吸收的影响。结果表明,低Cd(5mg·L-1)和高Cd(50mg·L-1)胁迫下,马蔺和鸢尾干物质量均呈上升趋势。高Cd处理70天时马蔺地上部和根系干物质量分别是处理前的2.37、2.31倍,而鸢尾在Cd处理40天后出现严重毒害症状。2种鸢尾体内Cd质量分数均随胁迫时间的延长呈先增后降的趋势。鸢尾地上部和根系Cd质量分数在低Cd处理后第30天时达到峰值,分别为220.5μg·g-1和1172.3μg·g-1,而马蔺根系Cd质量分数第40天时达到最大值1182μg·g-1,且地上部于第50天时达到峰值264.4μg·g-1。高Cd处理下,马蔺地上部和根系Cd质量分数均高于鸢尾。Cd胁迫还导致2种鸢尾属植物微量元素吸收代谢紊乱,对其根系Fe质量分数表现出"低促高抑"的效应,使地上部和根系Zn含量均下降,根系Cu含量增加,而对Mn吸收的影响相对较小。
The effects of Cd stress on development, Cd accumulation and microelement uptake of Iris lactea var.chinensis and I. tectorum were investigated by hydropinic culture. The results indicated that dry biomass ofI. lactea andI. tectorum increased under 5 mg·L^-1or 50 mg·L^-1 Cd stress. After 70 d exposure to 50 mg·L^-1 Cd, the dry shoot and root biomass ofI. lactea increased 2.37- and 2.31 -fold, but I. tectorum presented serious toxic symptoms after 40 days. Cd accumulation in the two species of Iris show a trend of rise and drop later subjected to 5mg＇L1 and 50mg.L＂l Cd with time. Cd concentration in the shoot and root of/. tectorum reached the peak value 220.5 μg·g^-1 and 1 172.3 μg·g^-1 after 30 d, but the root Cd concentration reached maximum 1182 μg·g^-1 after 40 d and the shoot Cd concentration reached its maximum 264.4 μg·g^-1 after 50d exposure to 5 mg·L^-1 Cd. And, Cd concentrations in the shoot and root ofI. lactea were higher thanI, tectonrum subjected to 50 mg·L^-1 Cd. Cd stress also led to the turbulence of the microelements uptake. Zn concentration in the shoot and root of the two species of Iris decreased with increase of Cd concentration and duration of treatment, but Cu concentration in the roots increased. Low concentration （5 mg·L^-1） of Cd promoted Fe uptake, high Cd （50 mg·L^-1） inhibited it.
出处
《生态环境》
CSCD
北大核心
2008年第2期651-656,共6页
Ecology and Environmnet
基金
国家自然科学基金项目(30270940)
江苏省农业高新技术项目(BG2003308)
