Effect of Mercury Stress in Soil on the Contents and Correlation of Mineral Elements of Flue-cured Tobacco Leaves

Differences of mineral elements content in flue-cured tobacco leaves under the stress of heavy metal mercury( Hg) were studied by the outdoor pot experiment in which five mercury concentrations( 0,10,30,50,100 mg / kg) were set. The results showed that the content dynamic changes of eight kinds of mineral elements in flue-cured tobacco leaves under Hg stress were not the same. With the development of growth period of tobacco,the contents of K,P,Ca and Mg in leaves gradually decreased; the contents of B and Fe in leaves firstly decreased,then increased,and reached the highest at 30 d after transplanting; the content of B reduced to the minimum at 45 d after transplanting and the content of Fe reduced to the minimum at 60 d after transplanting; the contents of Cu and Zn first decreased,then increased,and decreased again,both reached the highest at 30 d after transplanting and reduced to the minimum at 45 d after transplanting. The Hg content in middle leaves of tobacco gradually increased as Hg concentration in soil increased. As a whole,the eight kinds of mineral elements in tobacco leaves decreased as Hg concentration increased. There existed very significant correlation among K,Mg and Fe contents in tobacco leavesunder Hg stress.