La réversibilité des effets du cadmium sur les différents paramètres de la croissance chez la tomate cultivée en présence de NO3 − ou NH4 +

Abstract In order to understand the effects of heavy metals in morphological and physiological parameters affecting the growth of a plant, we followed the evolution of these same parameters in Cd pre—stressed tomato seedlings after Cd had been removed from nutrient solution. Seven day—old seedlings were grown for one week on hydroponic culture medium containing 5 mM NO3 − or NH4 + and enriched by 25 μM Cd for 8 days. After that, plants were transferred on the same media without Cd. Results obtained show that regardless the nitrogen form used Cd suppression results in resumption of growth activity in all organs. Parallel, we observe a resumption of foliar area, roots growth and increasing contents in Ca, ammonium and soluble total proteins in all plants issued from either nitric or ammoniacal nutrition. The resumption of the different parameters was shown important in plants received ammonium nutrient.