Excess Nickel Alters Growth, Metabolism, and Translocation of Certain Nutrients in Potato

ABSTRACT

To elucidate the deleterious effects of excess nickel (Ni) on potato (Solanum tuberosum) cv. ‘Chandramukhi’, plants were grown in refined sand in a complete nutrient solution for 40 days. On the 41st day, excess Ni was superimposed to potato plants at 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 mM for 108 days. A set of plants with a complete nutrient solution (0.0001 mM Ni) was maintained as control for the same period. After 12 days of metal supply (d52), in addition to growth depression plants at 0.5 mM Ni developed chlorosis on young leaves initiating from the base, gradually spreading downward. With increase in age chlorosis intensified and brown necrotic areas developed irregularly on the affected lamina. Later the similar symptoms appeared at lower supply of excess Ni (>0.3 mM) but the intensity was comparatively milder. Exposure of potato plants to excess Ni show retarded growth, decreased chlorophyll concentration, concentration of zinc (Zn) and iron (Fe) (except roots in both) and activities of antioxidative heme enzymes whereas increased the concentration of Ni, phosphorus (P) (except roots) and sulfur (S) (except roots) in different plant parts of potato.

Keywords:

• potato
• Ni toxicity
• chlorophyll concentration
• enzyme activities

ACKNOWLEDGMENT

The authors are grateful to Prof. C. Chatterjee for valuable suggestions during the course of experiment.