Notice of Retraction Effects of Cu Pollution on the Growth and Activate Oxygen Metabolism of Rape Crop in the Farm Ecosystem

Effects of Cu pollution on chlorophyll content and scavenging system of activated oxygen in leaves of rape (Brassica Chinensis L) were studied by cultivation experiments.The results showed that external symptoms ^ physiological and biochemical index and SOD activity were impacted by Cu treatments. The activity of SOD and contents of chlorophyll increased firstly in lower concentration of Cu (100 mg·kg -1 ), while the velocity of 02·-production and the cell membrane permeability had no marked change, and the balance of protective enzyme system was hold. Those may be regarded as a protecting function of plants. However, with the increase of concentration of Cu, negative effect had existed, the fronds were shorter and smaller, content of leaf pigments and the activity of SOD decreased drastically. The sensibility order of pigments to Cu stress was similarly Chlorophyll a>; Chlorophyll a+b >; Chlorophyll b. The velocity of 02·-production was increased sharply; the membrane penetration and electric conductivity were increased. Furthermore, the activate oxygen metabolism system of rape (Brassica Chinensis L) was destroyed. The results indicated that Cu stress had affected scavenging system of activate oxygen and had broken the balance of protective enzyme system.