铜与草甘膦复合污染对小麦种子发芽与根伸长的抑制作用

污染物的交互作用及其生态毒理效应已成为环境科学研究的重要方向.论文以小麦种子为供试作物,研究了重金属铜(Cu2+)与除草剂草甘膦复合污染对其发芽率以及发芽后的根长、芽长的影响,以表征Cu与草甘膦复合污染的生态毒性.研究结果表明,在实验浓度下,Cu2+单一污染对小麦发芽率没有明显的影响,对根伸长和芽长的抑制显著;而草甘膦单一污染对小麦发芽、根伸长和芽长均有明显的抑制效应.当Cu2+与草甘膦复合污染时,Cu2+的存在在一定程度上减弱了草甘膦对小麦发芽及芽长的抑制作用;而在根伸长实验中,在低草甘膦浓度条件下,Cu2+的存在在一定程度上增加了草甘膦对根伸长的抑制作用;在较高草甘膦浓度条件下,Cu2+的存在则降低了草甘膦对根伸长的抑制作用.Cu2+的存在减轻草甘膦对小麦毒性的可能原因是:草甘膦与Cu2+络合形成了毒性较小的稳定络合物,使草甘膦毒性降低或失去活性.

The Inhibition of the Combined Pollution of Copper and Glyphosate to the Seed Germination and Root Elongation of Wheat

Interaction of pollutions is one of the research focuses in current environmental sciences. The combined toxicity of copper and glyphosate to the inhibition rates of wheat germination, sprout length and root elongation was studied. Results indicated that Cu2+ had no obvious effect on the wheat germination but could inhibit the root elongation and sprout length significantly. Glyphosate had obvious inhibition effect on the wheat germination, sprout length and root elongation. When Cu2+ and glyphosate were combined, the presence of Cu2+ decreased the inhibition of glyphosate to wheat germination and sprout length. But for the root elongation, the Cu2+ increased the toxicity of glyphosate when glyphosate was at low concentrations and decreased the toxicity of glyphosate to root elongation when glyphosate was at high concentrations. The possible reason of Cu2+ decreased the eco-toxicity of glyphosate is the complexation reaction of Cu2+ and glyphosate.