匍茎翦股颖对Cu2+、Zn2+、Cd2+与Pb2+ 胁迫的生长响应与阈限浓度

采用砂培法,研究了匍茎翦股颖对Cu2+、Zn2+、Cd2+与Pb2+胁迫的生长响应及阈限浓度,结果表明:种子萌发率随着4种重金属浓度的增加而下降。对株高的影响是当重金属浓度小于100mg/L时会促进株高生长,高于100mg/L则产生抑制作用。Cu2+显著抑制根系生长,并随浓度的增加抑制效应愈加显著;在Cu2+浓度为600mg/L时匍茎翦股颖的根长比对照下降了93.75%。Cu2+、Zn2+、Pb2+浓度小于200mg/L时会促进地上生物量的增加,但高于200mg/L时,地上生物量会随着3种重金属的增加而减少。Cu2+、Zn2+浓度小于100mg/L或Cd2+、Pb2+浓度小于200mg/L会增加叶绿素的含量,高浓度会降低叶绿素的含量;Cd2+在浓度为600mg/L时显著降低叶绿素含量,与对照相比,下降了43.55%。匍茎翦股颖生长的综合效应分析表明,匍茎翦股颖对Cu2+胁迫最敏感,具有较低的阈限浓度,而Zn2+胁迫对匍茎翦股颖的生长影响最小,阈限浓度相对较高。

Growth response and threshold concentration of Agrostis stolonifera to Cu2+, Zn2+,Cd2+or Pb2+ stress

By sand cultural method,the experiment was conducted to investigate growth response and threshold concentration of Agrostis stolonifera to Cu2+,Zn2+,Cd2+ or Pb2+ stress.It was found that rate of seed germination decreased with increasing supply of Cu2+,Zn2+,Cd2+ or Pb2+.Heavy metal supply at concentration ≤100 mg/L increased plant height of A.tolonifera,whereas Cu2+,Zn2+,Cd2+or Pb2+supply higher than 100 mg/L decreased plant height.Cu2+ inhibited root growth significantly,and root length decreased with increasing Cu2+ supply.Compared with the control,root length of A.tolonifera was lowered by 93.5% at Cu2+ concentration of 600 mg/L.Aboveground biomass increased at Cu2+,Zn2+ or Pb2+ concentration ≤200 mg/L,but decreased with increasing concentrations when their concentrations were higher than 200 mg/L.Chlorophyll content increased at Cu2+,Zn2+ concentration ≤100 mg/L or Cd2+,Pb2+ concentration ≤200 mg/L,but tended to decrease at Cu2+,Zn2+ concentration ≥100 mg/L or Cd2+,Pb2+ concentration ≥200 mg/L.Only Cd2+ significantly lowered chlorophyll content of A.tolonifera by 43.5% at concentration of 600 mg/L.Synthetical effect of heavy metal on A.tolonifera growth indicated that A.tolonifera was most sensitive to Cu2+ stress with low threshold,but the effect of Zn2+ stress on A.tolonifera growth was the least.