Research On The Tolerance Of Polystichum Neolobatum Maleai And Dryopteris Fuscipes In Pb-Cd Complex Stress

Fern is an ancient tracheophyte, also one of unique natural groups during the evolution of the botanical system. By using Phytophysiology & Biochemistry enzyme system,atomic absorption spectrometry and electrochemistry, The threatise studied stress performance about two species of Dryopteridaceae:Polystichum neolobatum Maleai. and Dryopteris fuscipes under environmental stress of different concentrations of lead and cadmium. study and comparate the accumulation of lead and cadmium in the two species, The results show that:(1) Under the Pb-Cd sand cutural, the growth development of Polystichum neolobatum Maleai is inhibited seriously, poor performance in high concentrations and high mortality; while Dryopteris fuscipes grows basicly normally., Stress 15 to 22 days later,except CK,leatherleaves of Polystichum neolobatum Maleai. arise poison symptoms indifferent degrees, which are positive correlation to the concentration and time-dependent.The main symptom is:With the increase of the concentration and time extending,by the center of petiole the surface and margin of leaves appear from tawny to puce spots such as water stain, similar to the symptoms of frost damage. Stress 45 days later, the poison symptoms of the high concentration group of Polystichum neolobatum Maleai. appears dead, Stressing the Dryopteris fuscipes 15 to 22 days later,it grows basicly normally,35 days later, high concentration group leatherleaves begun to appear a small brown spots.45 days later, brown spots continue to spread to the petiole. The concentration of 400+800 treated group leatherleaves brown spots began to appear.(2) Through the heavy metal stress to Polystichum neolobatum Maleai and Dryopteris fuscipes Analysis the physiological and biochemical of the plants, find that there are many antioxidant mechanisms in plants. Polystichum neolobatum Maleai in the Pb-Cd combined stress,. Protective enzymes POD, SOD, CAT activity and lipid peroxide (MDA) content and concentration was positively correlated with the concentration that increased activity was also increased. Dryopteris fuscipes of POD, SOD and CAT activity and lipid peroxide (MDA) levels show under suppressed of 600+1200 treated group (high concentration).On the Contrary,200+400,400+800 treated group (low concentration) are active in the phenomenon. through measure the soluble protein content found, Polystichum neolobatum Maleai soluble protein content shows a downward trend with the concentration increased; Dryopteris fuscipes soluble protein content decreased in low concentrations while increased significantly in higher concentration.(3) Both of them are not have strong enrichment capacity to Pb-Cd. Neither of them are hyperaccumulator to Pb, Cd. But the Dryopteris fuscipes on Pb, Cd enrichment was greater than Polystichum neolobatum Maleai.