Combined toxic effects of cadmium and acid rain on Vicia faba L.

Abstract

Soil sample for this pot experiment was collected from Changsha County, an unpolluted area, and contained low heavy metal contents. The soil sample was air-dried, passed through a 2 mm sieve, and weighed 5.0 kg to each of 15 plastic tubs. These 15 tubs were divided into three groups. Cd(CH2COOh (pure) Was added to each group to make external Cd2+ contents he 0.0, 4.0, 6.0, 8.0, 10.0 mg/kg, respectively. Two weeks later 10 Vicia faba L. seedlings (Qidou 2) were planted in each tub. The first group was watered with distiIIed water (dw), the second and third groups were watered with sirnulated acid rain (pH 4.5 and 3.5, respectively. Heights of the Vicia faba L. plants were measured 90 days later. Before blossoming, injured symptorns were recorded (photos were taken), protective enzymes (surperoxide dismutase SOD and peroxidase POD) in the leaf and root tissues were determined, and the ultra-structures of leaf cells were observed on transmission electronic microscope H600.