Responses Of Three Polygonaceae Species To Water Stresses And Pollutants Exposures

This study explores the responses of three Polygonaceae species to water stresses and pollutants exposures , the choosing plants are Polygonum criopolitanum, Polygonum chinense and Polygonum hydropiper. This study includes two phrases: preliminary experiments phrase and executive experiment phrase. In the first phrase mainly responsible for cultivate and domesticated three plants.The first phrase experiment shows that after 30 days cultivation, the plants can stay in stable growth stages, after another10 days cultivation, we process water stress and observe the growth statues of plants.In drought processing experiment we found that under 30℃room temperature,after 3 days cultivating Polygonum chinense and Polygonum hydropiperenter wilting state, the next day Polygonum criopolitanum have the same response.Then carry out after water test ,Polygonum hydropiper and Polygonum criopolitanum return to normal growth status,but Polygonum chinense can not. In whole flooding process, three plants can stay in normal growth status and Polygonum hydropiper will have adventitious roots.In the test experiment phrase, we have drought processing,whole flooding processing and normal control processing plants. we measured content of plants water,content of relative moisture,content of MDA,Membrane permeability,content of Soluble sugar,content of Proline,Pn,E,Gs,Ci. In another experiment use water contain three different concentrations of TN,TP,Pb and purify water feeding plant,after 2 months cultivation,detecting the content of Pb in Plants,and remove rate of TN,TP in the water.After experiment we found that:1. The change of physiological and biochemical indexes show that Polygonum hydropiper response to drought threat quickly,it can adjust quickly to adapt to environment changing, the most apparent indexes are membrane permeability and content of soluble sugar. All the figure out the tolerance of drought stress,from high to low are Polygonum criopolitanum, Polygonum chinense ,Polygonum hydropiper.2. The change of Physiological and biochemical indexes show that Polygonum chinense and Polygonum criopolitanum response to flooding threat quickly,they can adjust quickly to adapt to environment changing,the most apparent indexes are content of MDA, soluble sugar and Proline. They can keep growing well, and all the indexes show they have wonderful water tolerance.3. Under three kinds of threat they all can grow well, blossom as normal.And all the indexes show they have the ability of purifing water. After 3 days, the remove rate of TN can reach 35%, the remove rate of NH₃-N can reach more than 20%, the remove rate of TP can reach 70% and Polygonum criopolitanum fit best for purify water.4. Different plants and different organs of the same plants, all have different purify ability of Pb. From this experiment,we found that the bioconcentration factors(BCF) of every plants are larger than 1,from high to low are Polygonum criopolitanum, Polygonum hydropiper, Polygonum chinense ; BCF of Polygonum criopolitanum larger than the other plants apparently(p<0.05);Polygonum chinense and Polygonum hydropiper have no obvious differences.