Effects of pH and nitrogen on cadmium uptake in potato

Abstract

This study investigated the effects of pH and nitrogen form and concentration on cadmium (Cd) uptake by potato (Solanum tuberosum L.) grown in hydroponic culture. Potato plants grown in a pH-buffered nutrient solution for 10 d were exposed for 24 h to 25 nM CdCl2 labelled with 109Cd. Plants showed a significantly higher Cd uptake and accumulation at pH 6.5 than at pH 4.5 and 5.5. Nitrogen supplied as nitrate (NO3-) generally resulted in a higher Cd uptake and accumulation than N supplied as ammonium (NH4+). This effect was most pronounced at pH 6.5. The N concentration increasing from 6.5 to 26 mM resulted in a decreased Cd influx when either NO3- or NH4+ was used. Cd translocation to the shoot was increased when NO3- was used as the sole N source. In conclusion, pH had a strong influence on Cd uptake by roots and N form is especially important for Cd translocation within the potato plant. © 2013 Springer Science+Business Media Dordrecht.