铜对三种豆科植物萌发及早期生长发育的抑制效应

采用水培实验研究了Cu2+对种子萌发和胚根胚芽伸长的抑制效应;采用盆栽实验研究了土壤中不同含量Cu对植物地上、地下部分长度和质量以及叶绿素含量的影响.结果表明:质量浓度≥400mg.L-1的Cu2+水溶液对三种植物种子的萌发产生显著的抑制作用,质量浓度越高阻抑越明显,对紫花苜蓿的抑制效应小于红三叶和沙打旺;对胚根伸长的抑制作用大于芽.过量Cu2+可显著降低植物叶绿素的含量,并对地上部分的生长产生明显的抑制作用;对紫花苜蓿及红三叶根系长度和质量有明显的促进作用,而对沙打旺则有明显的抑制作用.总体来看,紫花苜蓿对Cu污染的耐受程度大于红三叶和沙打旺.

Inhibition Effect of Copper on Seed Germination and Seedling Growth of Three Leguminous Plants

The inhibition effects of Cu²⁺ on seed germination and radicle/germ elongation were studied via hydroponical experiment, and the effects of different Cu²⁺ contents in soil on the length, weight and chlorophyll content of above-ground and underground parts of plants were studied via pot culture experiment. The results revealed that the aqueous solution in which the Cu²⁺ mass concentration greater than or equal 400 mg·L^-1 obviously inhibits the seed germination of the three plants: Medicago sativa, Trifolium pratense and Astragalus adsurgens. The higher the Cu²⁺ mass concentration, the more obvious the inhibition effect, and the inhibition effect on the first one is lower than that on the other two. In addition, the inhibition effect on the elongation of radicle is higher than that on germ. Excessive Cu²⁺ content will lower the chlorophyll content in plants with obvious inhibition effect on the growth of above-ground parts of plants. However, the Cu²⁺ content clearly accelerates the growth of length and weight of the root system of M. sativa and T. pratense, but it inhibits that of A. adsurgens obviously. As a whole, the endurability of M. sativa to Cu pollution is higher than that of the other two plants.