Cu对大麦和玉米的毒性效应

The Toxicological Response of Wheat(Hordeum Vulgare L)and Corn(Zea Mays)to Copper Stress

通过发芽试验及幼苗生长试验研究了重金属Cu在5、10、25、50、100mg·L-1浓度下对大麦和玉米的生态毒性效应,比较分析了大麦和玉米对Cu胁迫的敏感性。结果表明:对于发芽试验,当Cu浓度在25～100mg·L-1时,处理组与对照组相比发芽率明显降低(P<0.05)。而对于幼苗生长试验,在0～5mg·L-1时,Cu对植物幼苗的生长没有显著作用,在10～100mg·L-1作用下,根长、株高及根干重与Cu2+浓度呈显著的负相关;可溶性蛋白含量、叶绿素a、叶绿素b及叶绿素a+b在Cu为10～100mg·L-1作用下,与对照相比均显著降低(P<0.05)。玉米对Cu胁迫比大麦稍微敏感;各项指标的敏感性依次为:可溶性蛋白>根伸长>叶绿素>根干重>发芽率>株高>地上生物量。与其他指标相比,可溶性蛋白指标对Cu胁迫最具有敏感性,可作为Cu污染的生物标记物。

Differential tolerances of wheat （Hordeum vulgare L） and corn （Zea mays） exposed to copper toxicity were assessed in this paper. The influence of different copper concentration in the pot substrate on the seed germination and seedling growth was tested. The results showed that corn was more sensitive to copper stress than wheat. And in the seed germination experiment, copper concentration above 25 mg·L^-1 resulted in the significant inhibition of seed germination （P〈0.05）. In the seedling growth experiment, a reduction in root length was observed in the presence of 10 mg·L^-1 copper, and accompanied by a decrease in plant size and dry root weight. And the contents of chlorophylls and total soluble protein also decreased with the elevated copper concentration. There is a significant negative relationship between the copper concentration and the total soluble protein at 10-100mg·L^-1 copper（P〈0.05）. According to their sensitivity to the copper toxicity, the above indicators ranks in the following order： total soluble protein content〉 root elongation〉chlorophylls content〉underground biomass 〉seed germination〉 overground biomass. Among these indicators, the total soluble protein content is the most sensitive and can be used as a bioindicator of soil contamination by copper.