摘要
采用砂培法研究了早熟禾对不同浓度Cu2+、Zn2+、Cd2+和Pb2+胁迫的生长响应特征.结果表明,当Cu2+、Zn2+、Cd2+的浓度达100 m g/L时,早熟禾的种子萌发率、幼苗株高均有所下降,并随着胁迫浓度的增加,下降幅度增大;Pb2+对两指标的影响不太明显.Cu2+对根系及地上生物量具有抑制作用,尤其对根系生长抑制效应极为明显,当浓度增加到600 m g/L时,与对照相比,根长最高下降了96.67%.Zn2+、Cd2+和Pb2+在浓度超过200 m g/L时对早熟禾根系及地上生物量表现出抑制效应,并随着浓度的增加抑制效应增加.4种重金属对叶绿素的影响表现出一致的规律,即当浓度小于200 m g/L时对叶绿素的合成起促进作用,当浓度超过200 m g/L时,叶绿素的含量又随着处理浓度的增加而下降.
The growth responses of Poa pratensis to the stresses of Cu^2＋,Zn^2＋,Cd^2＋ and Pb^2＋ at different concentrations were studied by sand culture. The results revealed that with Cu^2＋ ,Zn^2＋ ,Cd^2＋concentrations reaching 100 mg/L,both the seed germination rates and young-seedling heights of P. pratensis declined to some extent and their decrements increased as the concentrations increased. Pb^2＋ did not show significant effect on these two indexes. Cu^2＋ inhibited the root and aboveground biomasses and the inhibitory effect on the root growth was particularly significant;with Cu^2＋ concentration coming to 600 mg/L,the root lengths decreased by as high as 96.67% ,compared with those in the control. With Zn^2＋,Cd^2＋ and Pb^2＋ concentrations going above 200 mg/L,the root and aboveground biomasses of P. pratensis appeared to be inhibited, and the inhititory effects became intensified as the concentrations increased. The four heavy metals appeared undifferentiated in their action patterns on chlorophyll, i. e. they enhanced chlorophyll synthesis with their concentrations standing below 200 mg/L and the chlorophyll contents declined as their concentrations continued to increase after reaching 200 mg/L.
出处
《西北植物学报》
CAS
CSCD
北大核心
2006年第1期183-187,共5页
Acta Botanica Boreali-Occidentalia Sinica
基金
天津市科技发展计划(培育)项目(043100611)
国家自然科学基金项目(59878033)
关键词
早熟禾
重金属
胁迫
生长响应特征
Poa pratensis
heavy metal
stress
growth response
