Study on the effects of Cr+3 accumulation on growth and some mineral nutrients concentrations in parsley (Petroselin um crispum)

Trivalent chromium is an essential trace element in balancing human and animals diet. Because of the role of this ion in carbohydrate and lipid metabolism, its deficiency causes appearance of diabetes symptoms and cardio-vascular diseases. For preventing chromium deficiency and undesirable effects resulting from using chemical supplements of Cr+3, chromium accumulator plants can be used as complementary food. For this purpose, effects of various concentrations of Cr+3 on growth and some mineral nutrients content in parsley (Petroselinum crispum) plants were studied. Parsley seedlings were grown on hydroponic culture (Hoagland) containing various levels of Cr+3 (0.1, 0.25, 0.75, 1, 1.5, 2 and 3 mg/l). After 5 weeks, the influence of Cr+3 on growth rate (root and shoot dry weight, root and shoot length and total biomass) and concentrations of Ca+2, K+, Na+ and P in roots and shoots were measured. Chromium accumulation was also determined in roots and shoots. Results showed that with increasing Cr+3 concentrations in medium, the root and shoot dry weights and lengths and content of mentioned mineral nutrients decreased. Significant decrease in the root and shoot dry weights were observed at 3 mg/l and 2-3 mg/lCr+3, respectively. Chromium caused significant decrease in the root and shoot lengths from 0.75 mg/l up to 3 mg/l. In high concentrations of Cr+3 (2 and 3 mg/l) Ca+2 content of the root and shoot decreased significantly. Significant decrease in K+ concentration in the root and shoot was observed at 3 mg/lCr+3. Treatments with 3 mg/lCr+3 caused significant decrease in Na+ concentrations of root. With increasing Cr+3 concentrations in medium, P content in the root and shoot increased that was significant from 0.75 mg/lCr+3 to 3 mg/lCr+3. With enhancing Cr+3 levels in medium, the concentration of this ion in the roots and shoots increased significantly. Chromium accumulation in the root was much higher than the shoots.