Study On Seed Germination And Seedling Growth Of Five Kinds Xerophytes Under Ni²⁺ And Cu²⁺ Stress

Jinchang City, Gansu Province is typical of the arid zone of mining cities,non-ferrous metals such as nickel, copper reserves highest in our country, with thecontinued exploitation of all kinds of non-ferrous metals, a large number of the slagpile up at the edge of the city, still contains a higher concentration in the slag heavymetals （copper and nickel）, and Jinchang special climatic conditions, few species inits growth. Poses a serious threat to the urban environment and the lives and safety ofthe people around the governance slag caused heavy metal pollution has become animminent issues.The paper respectively studies on the seedling germination and radicleelongation of five kinds of plants of Ceratoides lateens、Hedysarum scoparium、Artermisia ordosica、Heloxylon ammodendron、Caragana korshinskii under differentconcentration of nickel and copper ions stress. In order to filter out the strongresistance of the species, which provides evidence for the soil ecological restoration inthe tail mining area and heavy metal pollution area. The results showed that:（1）Seedling germination and germ growth of five plants have been promotedunder low concentration of Ni²⁺or Cu²⁺stress: seed germination role of Ceratoideslateens、Artermisia ordosica、Caragana Korshinskii under Ni²⁺stress higher thanCu²⁺, seed germination role of Hedysarum scoparium、Heloxylon ammodendronunder Cu²⁺stress higher than Ni²⁺; Germ growth of Artermisia ordosica andHeloxylon ammodendron are stronger under low concentration of nickel stress,Ceratoides lateens and Heloxylon ammodendron are stronger under low concentrationof copper stress; Toxicity of radicle copper stronger than the nickel.（2）Under single stress of Ni²⁺or Cu²⁺, the sequence of five plants under thenickel stress as: Caragana Korshinskii Kom＞Ceratoides lateens reveal＞Hedysarumscoparium＞Heloxylon ammodendron＞Artermisia ordosica; and under the nickelstress as： Ceratoides lateens reveal＞Heloxylon ammodendron＞Hedysarumscoparium＞Caragana Korshinskii Kom＞Artermisia ordosica. （3）The sequence of germination index and germination rate of five plant seedsunder different concentrations of Ni²⁺and Cu²⁺stress: Ceratoides lateens reveal＞Caragana Korshinskii Kom＞Artermisia ordosica＞Heloxylon ammodendron＞Hedysarum scoparium.（4）Under Ni²⁺and Cu²⁺stress, seedlings germ length value was lowconcentration slowly increased and then as the concentration increased sharplydeclined. The sequence of five plants seedlings germ under different concentrations ofNi²⁺、Cu²⁺as: Caragana Korshinskii＞Ceratoides lateens＞Heloxylon ammodendron＞Hedysarum scoparium＞Artermisia ordosica; The sequence of the five plantradicle under different concentrations of Ni²⁺, Cu²⁺stress: Ceratoides lateens＞Heloxylon ammodendron＞Hedysarum scoparium＞Artermisia ordosica＞CaraganaKorshinskii.（5） Influence of five plant seed germination and seedling growth has a significantsynergistic effect under different concentrations of Ni²⁺, Cu²⁺stress.Under Single stress or the composite stress conditions, Ceratoides lateens andCaragana Korshinskii of Ni²⁺、Cu²⁺stress have a strong resistance, and theiradaptability to the ecological environment of the arid and semi-arid areas is strong, soit can be the end of mine ecological Jinchang repair priority species.