| In recent years,the rapid development of industry and agriculture has caused more and more environmental problems.In water and air,the heavy metals remaining in the soil will not only have a certain effect on microorganisms,but also on the activity of enzymes,resulting in the decline of soil physical properties and the growth of plants.Using the land accumulation index method to evaluate the pollution,it is found that the cadmium content in the vegetable greenhouse in Xinxiang City is grade 6,which belongs to severe environmental pollution;The pollution degree of zinc and copper is grade II,belonging to medium pollution;Lead;Manganese pollution level is grade I,belonging to mild and moderate pollution.Taking Jinhua sunflower as the main research object,using the cultivation form of hydroponic culture,this experiment deeply studied the growth process and heavy metal absorption characteristics of Jinhua sunflower under the environmental stress of heavy metals Zn,Cu,Mn and Pb,so as to deeply grasp the enrichment characteristics of Jinhua sunflower to heavy metals and lay a theoretical basis for the development of phytoremediation technology of heavy metal polluted soil.The specific results are as follows:（1）The important effect of zinc stress on the germination rate and zinc ion accumulation of Jinhua sunflower seeds.From the comparison of the degree of zinc stress and inhibition in various index receptors of seeds,the results showed that under zinc stress,different concentrations had the greatest effect on the zinc accumulation in Jinhua sunflower seeds and the least effect on the germination rate of Jinhua sunflower seeds.Under the direct influence of higher concentration of zinc ion stress,the zinc accumulation in Jinhua sunflower seeds is relatively high.There is a linear positive correlation between zinc ion stress and zinc accumulation in Jinhua sunflower seeds and plants.This means that the higher the zinc concentration in the zinc acetate solution,the higher the amount of zinc acetate ion accumulated in the sunflower plant.Jinhua sunflower extract has the special ability of super enrichment and adsorption of heavy metal zinc ions in soil,and can effectively adsorb a large amount of zinc ions contained in heavy metals in soil.Therefore,the effect is very obvious when using Jinhua sunflower as the restoration and protection material of forest vegetation,and it also has a good vegetation restoration and protection effect on the areas polluted by heavy metals in soil,especially suitable for planting in some heavy industrial areas and areas vulnerable to serious pollution by high concentration soil heavy metal Zn in the environment of some mining areas.The introduction of this plant material can also effectively improve the natural environmental conditions in these areas,Improve the healing ability of soil.（2）Copper stress has an important impact on the germination speed and copper ion accumulation in the seed.From the comparison of the degree of copper stress and inhibition in various index receptors of the seed,the effect of different concentrations of copper stress on the copper accumulation in the seed is the largest,and the effect on the germination potential of the seed is also the weakest.This is mainly because after the seeds are imbibed or germinated and mature,the radicle can first break through the seed skin due to rapid absorption of a large amount of water,so that the radicle can far exceed the germ in the amount of heavy metal copper ion accumulation and the time process of heavy metal stress absorption.Therefore,the root can directly fix and adsorb a large amount of heavy metal copper ion on the absorbed part,so the higher the zinc concentration in copper acetate solution,The higher the amount of copper acetate ion accumulated in sunflower plants.Therefore,we can consider using sunflower as an enrichment plant for the remediation and growth of copper pollution.（3）The stress of manganese has an important impact on the germination speed and the accumulation of manganese ions in the seed.From the comparison of the stress and inhibition of manganese in various index receptors of the seed,the stress degree of manganese is negatively linearly and positively correlated with the change degree of total manganese ion content in the seed and young bud plant at the germination stage.With the long-term continuous and stable increase of the content level in the soil of manganese solution,The level of manganese ions in sunflower seeds will show a stable and continuous upward trend for a long time.This also shows that under manganese stress,the effect of different concentrations on the accumulation of manganese in Jinhua sunflower seeds is also the strongest in nature,and the effect on the germination potential of Jinhua sunflower seeds is the weakest.This is because when the seeds swell and sprout,the radicle quickly absorbs water,elongates and breaks through the seed coat,so that the root is on the site.Therefore,the higher the manganese concentration,the higher the manganese accumulation in the sunflower seeds.Therefore,we can consider Jinhua sunflower as an enrichment plant for the restoration of soil polluted by manganese.（4）The important effect of lead stress on the germination speed of Jinhua sunflower seeds and the lead ion accumulation in Jinhua sunflower seeds.According to the comparison of the degree of lead stress and inhibition in various index receptors of seeds,when the lead stress treatment at high concentration,the enrichment coefficient will be increased accordingly when the lead content of heavy metals in Jinhua sunflower seeds is high.From the experimental analysis results,the effect of lead stress on the lead accumulation in sunflower seeds is the strongest.The greater the lead accumulation in sunflower seeds,the higher the enrichment coefficient will be.Therefore,we can consider using sunflower as an enrichment plant to repair lead pollution.The results showed that when the content of lead ion was high,lead ion significantly inhibited the germination of sunflower seeds,which also showed that lead had a considerable toxic effect on seed germination. |
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