Analysis Of Absorption And Accumulation Ability And Heavy Metal Stress Resistance Of Three Shrubs

The growth increment variance and physiological response of potted biennial seedling in greenhouse of three superior greening shrubs in north area,Weigela floridacv,Lonicera maackii,Cerasus glandulosa,under heavy metal stress,including Hg,Cd,Zn,Cu,Pb were studied in this paper.The resistance was also analyzed and appraised.It analyzed the absorption and accumulation ability of the toot and leaf of 3 shrubs,measured and calculated the distribution coefficient of heavy metal in the plant and compared transport difficulty for 3 shrubs.The growth index of plant height and ground diameter was selected to study the effect of heavy metal on the growth increment.The result showed that Zn,Cu and Pb with low concentration will promote plant growth and high concentration will restrain the growth;Cd with high concentration will promote and low concentration will restrain plant growth.The plant height and ground diameter have same character and accordant result.Hg has little effect on plant growth.The effect of heavy metal on the physiology of 3 shrubs was studied based on the measurement of MDA content,Pro content,POD activity and SOD activity.The results was that the biggest resistance of 3 shrubs under Hg and Cu stress is Cerasus glandulosa,Lonicera maackii is moderate and Weigela floridacv smallest;the order under Cd and Zn stress is Lonicera maackii,Cerasus glandulosa and Weigela floridacv,under Pb stress is Weigela floridacv,Lonicera maackii and Cerasus glandulosa.According to the heavy metal root absorption test,Weigela floridacv has the biggest ability of absorbing Cd,Zn and Cu;Cerasus glandulosa absorbed Pb and Lonicera maackii absorbed Hg greatly.The result of leaf enrichment test showed that Lonicera maackii has biggest enrichment ability of Hg,Cd and Pb,Weigela floridacv has the enrichment ability of Zn and Cu.The enrichment ability is directly related with root absorption ability.The distribution coefficient of heavy metal in 3 shrubs was calculated based on the results of root and leaf enrichment ability.The results showed that the distribution difficulty of Hg has no obvious different for 3 shrubs,the biggest is Weigela floridacv,Cerasus glandulosa is moderate and Lonicera maackii is smallest;under Cd stress Lonicera maackii has maximum transport distribution coefficient and Lonicera maackii has minimize coefficient;the order under Zn stress is Cerasus glandulosa,Lonicera maackii and Weigela floridacv;under Cu stress is Lonicera maackii,Cerasus glandulosa and Weigela floridacv;under Pb stress,Weigela floridacv is maximum and Lonicera maackii is minimize.