Growth Response Of Four Chemical Cinnamomum Camphora(L.) Presl To Copper Stress

The problem of soil pollution is a major concern of today’s society.among which heavy metal pollution has attracted much attention.Jiangxi is one of the serious provinces with heavy metal pollution,such as copper pollution in dexing of jiangxi and non-ferrous metal pollution in ganzhou.Cinnamomum camphora is a common broad-leaved tree species in the Yangtze River basin.It is also an important characteristic economic tree species,has strong adaptability and stress resistance.According to the branches and leaves essential oil content of main component can be divided into chemical types such as linalool camphora,lemon camphora,camphora and borneol camphora.In this paper,the cuttings of 1-year-old linalool camphora,lemon camphora,camphora and borneol camphora seedlings were used as experimental materials.Pot-control experiments were carried out to simulate Cu stress in different concentrations of heavy metals.The growth response of four chemical Cinnamomum camphora to heavy metal Cu stress was studied.The research results are as follows:（1）Under Cu stress,with the increase of treatment concentration,the growth indexes of various chemical Cinnamomum camphora（growth of height,ground diameter growth,single plant aboveground,underground and total dry weight）showed a downward trend,four chemical types.Cinnamomum camphora can grow normally under Cu≤600mg/kg,among which linden（50mg/kg）,linalool camphora（50mg/kg）and linalool camphora（150mg/kg）grow slightly stronger than control（CK）,The growth status of camphora was gradually inhibited with the increase of Cu treatment concentration.The four chemical Cinnamomum camphora（linalool camphora,lemon camphora,camphora and borneol camphora,the same below）were the worst in the treatment with high concentration of 600 mg/kg.Compared with the control,the total dry weight decreased by 66.12%,85.81%,80.97%,and 42.01%,respectively.（2）The chlorophyll content,net photosynthetic rate,stomatal conductance and transpiration rate of four chemical Cinnamomum camphora leaves decreased with the increase of copper concentration,and decreased with the extension of stress time.Intercellular CO₂ concentration（Ci）in leaves of lemon camphora,camphora and borneol camphora increased with the increase of copper concentration and the extension of stress time,while linalool camphora decreased with the increase of copper stress concentration and increased with the extension of time.（3）Under the stress of Cu,the content of MDA in the leaves of lemon camphora,camphora and borneol camphora increased with the increase of Cu concentration and the prolongation of stress time.The content of MDA was the same as the treatment concentration.The increase was in the ascending trend;the up-down-up trend was observed with the extension of stress time;the POD activity of leaves in each treatment group increased with the prolongation of stress time,while the activity of SOD increased first and then decreased with the prolongation of stress time.The activities of POD and SOD in the leaves of lemon camphora,camphora and borneol camphora showed a trend of increasing first and then decreasing.The protein content of leaves of linalool camphora,lemon camphora and camphora all increased first and then decreased with time.The trend showed that the leaf protein content of the treatment group of the borneol camphora was decreasing with the extension of the stress time.（4）Under the Cu stress,the Cu content of the four chemical Cinnamomum camphora showed root>leaf>stem,and the absorption of Cu by Cinnamomum camphora was mainly concentrated in the root system.With the increase of treatment concentration,the four chemical Cinnamomum camphora were all parts.The absorption of Cu was significantly different,and the absorption of Cu by the root system reached the maximum in the high concentration of 600 mg/kg,which was 16.26,24.67,17.77,8.08 times of the control group,respectively.（5）The Cu resistance of the four chemical Cinnamomum camphora was evaluated by the combination of the principal component and the membership function of each individual Cu-resistant coefficient.The Cu resistance was judged according to the comprehensive scores of the four chemical Cinnamomum camphora:linalool camphora（0.651）>linalool camphora（0.515）>camphora（0.407）>lemon camphora（0.388）,linalool camphora resistance to Cu is slightly stronger than the other three chemical Cinnamomum camphora.