Effects of cadmium stress on physiology and growth of different tobacco varieties

【Objective】Pot experiment was carried out to study the effects of Cd addition on physiology and the growth of three tobacco varieties.【Method】Three main tobacco varieties in Fujian,Cuibi 1,K326 and Yunyan 87,were selected to study the effects of different Cd additions on chlorophyll content,active oxygen metabolism,chlorophyll fluorescence,and height and biomass of tobacco varieties.【Result】Cd increased the content of photosynthetic pigment of Cuibi 1,while inhibited those of K326 and Yunyan 87.With the increase of Cd addition,activities of SOD and POD of three varieties increased firstly followed by a decrease.Cd addition increased MDA contents of all the three varieties without significant difference.The activity of photosynthetic reaction center in tobacco leaves decreased significantly under Cd stress and the inhibition on photosynthetic activity of K326 was the strongest.The growth of Cuibi 1and Yunyan 87 was promoted with low Cd additions whereas it was inhibited with high Cd additions.The growth of K326 was suppressed regardless of Cd additions.【Conclusion】Different tobacco varieties showed different sensitivities to Cd stress,and K326 and Yunyan 87 were more sensitive than Cuibi 1.