重金属铅镉胁迫对芋生长发育和产量的影响

Effects of Pb or Cd Stress on the Development,Growth and Yield of Taro

采用盆栽试验研究了0(对照),500、1 000、1 500、2 000 mg·kg^(-1)和2 500 mg·kg^(-1)6个浓度的铅(Pb)与0(对照)、0.5、1.0、1.5、2.0 mg·kg^(-1)和2.5 mg·kg^(-1)6个浓度的镉(Cd)溶液分别处理土壤对芋生长发育和产量的影响。结果表明,Pb胁迫抑制芋植株的生长,株高最大低于对照25.3%,对芋叶长、叶宽的影响不显著;而Cd浓度在1.0 mg·kg^(-1)以上显著促进了植株的生长,株高最大高于对照42.1%,最大叶长高于对照60.1%,最大叶宽高于对照60.9%。在1 000 mg·kg^(-1)和1 500 mg·kg^(-1)Pb胁迫下,叶绿素含量显著高于对照,浓度大于1.0 mg·kg^(-1)时Cd胁迫显著高于对照;Pb胁迫MDA含量同比对照显著增加,最大增加了60.8%,Cd胁迫仅在1.0mg·kg^(-1)显著高于对照45.4%。Pb胁迫可溶性糖含量先升后降,1 000 mg·kg^(-1)时显著高于对照40.6%,Cd胁迫时呈上升趋势,最大高于对照33.5%;Pb胁迫可溶性蛋白呈上升趋势,最大高于对照144.0%,Cd胁迫时先上升后下降,1.5 mg·kg^(-1)时显著高于对照37.0%;Pb、Cd胁迫均使SOD活性下降,最大下降幅度分别为37.8%和60.0%,使POD和CAT活性增强,POD最大增强幅度分别为119%和78.7%,CAT最大增强幅度分别为298.5%和65.5%。Pb或Cd胁迫均导致芋产量明显下降,最大下降分别为53.6%和56.5%。

The aim of the study is to investigate the effects of heavy metal, Pb or Cd, on development, growth and yield of taro by pot culture under different concentrations（0, 500, 1 000, 1 500, 2 000 mg·kg^（-1）and 2 500 mg·kg^（-1）Pb or 0, 0.5, 1.0, 1.5, 2.0 mg·kg^（-1）and 2.5 mg·kg^（-1）Cd）. The results showed that the growth was inhibited under Pb stress and the height was 25.3% lower than the control, but was promot-ed at more than 1.0 mg·kg^（-1）Cd stress, and the biggest plant height, leaf length and leaf width was 42.1%, 60.1% and 60.9% higher than the control, respectively. The chlorophyll content under 1 000 mg·kg^（-1）and 1 500 mg·kg^（-1）Pb was significantly higher than the control, and chlorophyll content under more than 1.0 mg·kg^（-1）Cd was higher than the control. The content of MDA under Pb stress increased significantly with the peak value 60.8% higher than control, and MDA only under 1.0 mg·kg^（-1）Cd stress was 45.4% higher than the control. The soluble sugar increased and then decreased under Pb stress, which was 40.6% higher than the control under 1 000 mg·kg^（-1）Pb stress. The soluble sugar under Cd stress increased up to a peak value of 33.5% higher than the control. The content of soluble protein under Pb stress increased significantly with the peak value of 144.0% higher than the control. Under Cd stress, however, soluble proteins increased and then decreased with a peak value of 37% higher than control under 1.5 mg·kg^（-1）Cd. The activity of SOD declined remarkably under either Pb or Cd stress,leading to a least value of 37.8% and 60.0% lower than the control, respectively. The activity of POD and CAT was enhanced under Pb and Cd stress. The peak value of POD activity under Pb and Cd stress was 119.0% and 78.0% higher than the control, respectively. The peak val-ue of CAT activity was 299.4% and 64.1% higher than control respectively. In addition, Pb or Cd stress had an obvious negative effect on the yield of taro, which decreased to 53.5% and 56.5% of the control, respectively.