谷子幼苗对土壤铅、铬的生长响应及吸收积累的差异性

采用盆栽土培试验，研究了谷子幼苗对土壤中不同含量铅（Pb）、铬（Cr）的生长响应和吸收积累的差异性。结果表明，在所试浓度（50～800 mg·kg^-1）范围内，Pb、Cr在谷子幼苗地上部和地下部的积累量存在较大差异，幼苗重金属的吸收富集和转运系数均为Pb大于Cr、Pb、Cr胁迫对幼苗生物量的影响表现为低浓度的促进和高浓度的抑制作用，但Cr对生物量的影响比Pb更强。相同处理条件下，幼苗茎叶中可溶性蛋白质、DNA含量和增色效应对Pb、Cr的响应也有明显差别，Cr对幼苗的生理毒性和DNA损伤效应的作用强度大于Pb。

Differences in Growth Response to Cr,Pb Stress and Their Uptake and Accumulation of Foxtail Millet Seedlings

Heavy metals Pb and Cr are two primary environment pollutants. Pb and Cr are neither essential nutrient elements for the growth of plants, nor participates in the process of cell metabolism. The differences in growth response to Pb, Cr stress and their uptake and accumulation of foxtail millet (Setaria italica(L) Beauv) seedlings were studied using a pot culturing after treatment for 30 d. The results indicated that at the concentrations of 50-800 mg·kg^-1, there were significant differences in the content of Pb, Cr in the roots and shoots of foxtail millet seedlings. In the seedlings, both the uptake coefficients and transmission coefficients of Pb were higher than those of Cr. Both Pb and Cr stress improved the biomass of seedlings at low concentrations while inhibited at high concentrations, however, the effect of Cr was stronger than that of Pb. At the same treatment condition, there were significant differences in the content of soluble protein, DNA content and DNA hyperchromic effect between Cr and Pb in foxtail millet seedlings, and the order of two heavy metals on the phytotoxic effects and DNA damage effects was Cr>Pb.