The Response To Lead(Pb)、Copper(Cu) Stress And Pb-accumulating Characteristics Of Hydrangea Quercifolia

Hydrangea quercifolia were cultivated in hydroponics and potted respectively, in which were treated by lead and copper stress that the growth and plant physiological index of H. quercifolia were tested. The results shown as follow.(1) Effects of Pb stress on the growth and plant physiological index of H. quercifoliaThe effects of Pb stress on the seedling growth and physiological parameters of H. quercifolia were studied that were treated by different concentration of lead in hydroponical culture in18day after lead treated. The results showed that the chlorophyll content in leaves were higher than contrast(CK) that in the treating of lower lead concentration (≤100mg/L). The chlorophyll content by treating of200mg/L were less than CK. MDA content were increased that companied by the Pb concentration increasing, for which there was none significant differences between the Pb concentration from50to150mg/L treating and CK, but200mg/L Pb treatment was the highest in MDA content which was207percentage of CK. The activities of POD and SOD in the leaves of H. quercifolia that was under Pb stress in different concentration were increased in lower concentration of lead and decreased in higher concentration of lead. The activities of POD was165percentage and SOD was221percentage of CK which was treated by100mg/L Pb.(2) Effects of copper stress on the growth and partial physiological parameters of H. quercifoliaThe growth and physiological parameters was studied by treated with copper in different concentration, the result shown that the plant dry weight and Chlorophyll a (Chl.a) and Chl.b as well as Carotenoids content was decreased but decreased in MDA content and membrane permeability with the increasing in Cu2+concentration in which the content of Chl.a decreased significantly to25%respectively with35mg/L Cu treatment, and the activities of SOD decreased significantly with15mg/L Cu treatment comparing to CK. SOD activity increased significantly that was about211percentage of CK treated with15mg/L Cu.(3) Effects of different organic acids on physiological characteristics of seedlings of H. quercifolia cultivated in Pb tailingIn this study, the EDTA and CA was applied in growing media of Pb tailings and the plant physiological index including in Chl. content, lipid peroxidation and antioxidant enzyme activities and proline content of H. quercifolia was measured. The results shown that both Chl.a and Chl.b content increased significantly at0.5mmol/kg EDTA treatment which was1.39times of CK, and Chl.b was1.47times of CK. There was none significant difference in Chl.a besides treated by2.0mmol/kg CA. MDA content in leaves of H. quercifolia was the lowest which was treated by.0mmol/kg EDTA that was121percentage of CK, and it was2.03times as many as CK which was treated by2.0mmol/kg CA. The POD, SOD and CAT activities increased significantly respectively that was treated by both EDTA and CA.(4) H. quercifolia cultivated in growing media of Pb tailing that was applied oganic acids and its growth and accumulating metals was testedThe plant was cultivated in lead tailings mixed with citric acid (CA) and ethylene-diamine-tetraacetic acid (EDTA) separately and the lead ion in plant was measured. The results showed that the Pb content in plant both roots and shoots significant increased progressively by treating with the growing media in which was the mixes lead tailing with EDTA at the concentration of0.5mmol/kg,1.0mmol/kg,1.5mmol/kg and2.0mmol/kg than CK, for which was211%,135%,146%and230%in shoots and about128%,144%,160%and166%in roots as CK. The Pb content in shoots was the most that was treated by lead tailings mixed with CA2mmol/kg that was about411%higher than CK. The results showed that CA and EDTA could be promoted the tolerability of H. quercifolia that could be more effectively to restore lead tailing.