Effect Of Cd And Pb Pollution On Physiology Biochemistry Characters And Quality Of Tobacco

In order to understand the effect of Cd and Pb pollution on physiology-biochemistry characters and quality of tobacco, pot experiments were carried out at Henan Agricultural University and Demonstration Plot of Scientific Research and Teaching during 2002-2004. The results were showed as follows:Firstly In three generational stages(Rosette stage.Budding stage and Harvest stage) of tobacco, the effect of Cd, Pb pollution in soil on physiology-biochemistry indexes of tobacco is obvious. As increasing of the content of Cd and Pb in soil, content of chlorophyll, chlorophyll a/b value decreased; the activity of SOD increased first and decreased afterwords, and the effect is biggest in the time of harvesting, there was a highest SOD activity when Cd content is 600 mg.kg~-1, to Pb, it is 300 mg.kg~-1; POD activity increased and there was a large increasing in the rosette stage; content of MDA and membrance permeability also increased, the correlativity between MDA content, membrance permeability and concentration of Cd and Pb in soil assumed bally plus pertinency; as increasing of the content of Cd and Pb in soil, content of GSH, the activity of ATPase and root activity decreased and assumed negative pertinency, especially, content of GSH, the activity of ATPase, root activity and concentration of Pb assumed bally negative pertinency.Secondly, the effect of Cd, Pb pollution in soil on photosynthesis and fluorescence characters was studied, results showed that, as increasing of the content of Cd and Pb in soil, the net photosynthetic rate (Pn), stoma guide rate (Gs), PSII activity (Fv/Fo), maximal PSII light energy transformation efficiency (Fv/Fm), the photochemical quenching coefficient (qP), the non-photochemical quenching coefficient (qN),the apparent photosynthetic electron transport rate(ETR) ,and the ratio of photochemical quantum yield of PSII (O2) decreased; as increasing of the content of Cd in soil, CO2 concentration in internal cells (Ci) increased, however, as increasing of the content of Pb in soil, CO2 concentration in internal cells (Ci) decreased.Thirdly, the effect of Cd and Pb pollution on the amount of soil microbe in tobacco root extent and the quality of tobacco leaves indicated that, the more Cd and Pb in soil , the less soil microbe in tobacco root extent. The degressive degree of soil microbe was maximal on low level of Cd ( ≤ 10 mg kg~-1) and Pb (≤300 mg kg~-1); the indexes of quality of tobacco leaves, the ratios of Reductive Sugar/Nicotine and Total-N/Nicotine increased, and the scales of the main compo-...