Effects Of Different PH On Heavy Metal Absorption Of Blueberry

The research was carried out in tissue culture, pot culture and field culture experiment, of two blueberry species--Northblue and Blomidon. Heavy metal elements were added into the soil and its pH was adjusted to 5.8,4.8,3.8. After several days of cultivation, the contents of heavy metal (Pb, Cd, Hg, Cr) in roots, leaves as well as fruits were measured by ICP-MS after samples were digested by acid mixture.The results of tissue culture indicated that the growth conditions of blueberries were not obviously affected by combined pollution of four heavy metal elements. Two spices of blueberries acted merely the same in heavy metal absorption, despite that the amount absorbed by Northblue was slightly higher. The concentration of Pb, Hg, Cr in blueberries were lower at pH 4.8, than at pH5.3; the situation of Cd was not evident.The pot and the field culture experiment showed that the heavy metal absorption ability stayed the same despite of the blueberries under combined heavy metal pollution or simple one. The experiment also pointed out that the living conditions of blueberries were affected when the soil pH went low enough, in this case, pH3.8. The heavy metal elements absorbed by blueberries were mainly accumulated in roots, in which had a concentration 10 to 20 times more than those in leaves, and over 100 times more than in fruits. The results were true in both species. As the soil pH went lower, the concentration of Pb, Hg, Cr in blueberries grew larger, whereas the situation of Cd was opposite.After 100 days cultivation, the Cd or Hg absorbed by blueberry fruits was within the limit of healthy food standard (GB2762-2005). The element of Cr, however, made its contents as many as 1.6 times of the standard when a third of the standard amount (GB 15618-1995) was added into the soil, and for Pb, the contents in fruits reached a half amount of the standard level when this element in soil was only 1/8 of the limited value. pH adjustment can lower the Pb content in blueberry leaves used for healthy tea processing.