Effect of vanadium on plant growth and its accumulation in plant tissues

Hydroponic experiments were conducted to investigate vanadium uptake by Chinese green mustard and tomato plants and its effect on their growth. Twenty-eight (Chinese green mustard) and 79 days (tomato) after germination, the plants were exposed for a further seven days to a solution containing six different concentrations of ammonium metavanadate (0-80 mg/l NH4VO3). The vanadium accumulated in the plant tissues were determined by ion-interaction high performance liquid chromatography, with confirmation by magnetic sector ICP-MS. The results indicated that nutrient solution containing more than 40 mg/l NH4VO3 affected plant growth for both Chinese green mustard and tomato plant. Chinese green mustard grown in the solution containing NH4VO3 at the concentrations of 40 and 80 mg/l had stem length, number of leaves, dry weight of leaf, stem and root significantly lower than those of plants grown in the solution containing 0-20 mg/l NH4VO3. Tomato plants were observed to wilt after four days in contact with the nutrient solutions containing 40 and 80 mg/l NH4VO3. As the vanadium concentrations increased, a resultant decrease in the stem length, root fresh weight, and fruit fresh weight were noted. The accumulation of vanadium was higher in the root compared with leaf, stem, or fruit. Measured levels of vanadium, from a nutrient solution containing 40 mg/l NH4VO3, were 328, 340, and 9.66x10 g/g in the leaf, stem and root for Chinese green mustard, and 4.04 and 4.01x10 g/g in the fruit and roots for tomato plants, respectively.