Résumé:
The plant's need for trace elements falls within a range between a deficiency threshold and a toxicity threshold. Plants also take up trace elements in their environment that have no known metabolic function to date (e.g. Cd, Hg, Pb, As, etc.) and are therefore considered non-essential.
Our study was carried out with the aim of determining the effects of four doses of lead nitrate ((Pb(No3)2) at different doses (0.03 g/l and 0.3g/l and 3.3g/l) on some anatomical and physiological parameters of germination (percentage of germination and average germination time).
The average values of the length of the tigellae present respectfully (1, 3, 5, 7.10 cm) in the plants treated with four doses of lead nitrate ((Pb(No3)2) at different doses (0.03 g/l and 0.3g/l and 3.3g/l) compared to the control with the highest value (11cm) and average values of the length of the radicles reveal a decrease for the doses (33.12 and 331.2 and 3312 ppm).
There was a remarkable decrease compared to the control with a slight increase for the dose of 3.3g/l of lead nitrate ((Pb(No3)2).This explains why this metal (lead) has a depressing effect on the germination of the tomato Lycopersicon esculentum Mill.
