氰对小麦种子萌发和幼苗生长生态毒理效应的研究

Eco-toxic Effect Study of Cyanide on Seed Germination and Seedling Growth Wheat

通过水培试验,比较研究了水培液中不同氰浓度对小麦种子萌发及幼苗生长的生态毒理效应。结果表明,低浓度氰(<5.0mg·L-1)对种子萌发过程中萌发率、α-淀粉酶及幼苗和根生长等指标有促进作用;高剂量氰(>5.0mg·L-1)时,对各指标具有胁迫效应。通过进行氰浓度和小麦种子发芽各项指标抑制率之间的相关和回归分析,表明两者呈现出极其显著正相关关系。氰对种子根生长的抑制作用远远大于芽生长抑制作用,小麦根伸长抑制率可作为化学物质生态风险评价的一项生物标志物。

With the severe shortage of water resources, sewage irrigation was applied more and more widely as an important mean to alleviate water deficit. Although numerous experiments have shown that the sewage irrigation can increase organic matter content in soils, it may also cause some negative effects as decreasing enzyme activity of soils, accumulating heavy metals in soil and crops, reducing crude protein and amino acids of the crop seeds, and lowering quality of agricultural products. This paper dealt with eco-toxicity study of cyanide on seed germination and seedling growth of wheat （Triticum aestivum） crop through hydroponic culture experiments. The results showed that the low concentration of cyanide （under 5.0 mg·L^-1 ） could promote the seed germination and seedling growth of wheat, whereas the high concentration of cyanide （above 5.0 mg·L^-1） greatly reduced the germination rate, the seedling growth, and or-amylase activity. Through a series of correlation analysis, we found that there was a significantly positive correlation between the inhibition rate of seed germination indices of wheat and the concentration of cyanide in solution. The inhibition of the root elongation rate was stronger than that of seed germination rate. Due to the highest sensitivity of the root elongation to cyanide concentrations, the change in root elongation rate might be the best bio-marker among those of this study for ecological risk assessment on cyanide toxicity to wheat crop.