Lead (Pb) toxicity affects seed germination and early seedling growth of Solanum lycopersicum l

Abstract

Lead (Pb) contamination may impair seed germination and early plant development, affecting crop establishment. This study evaluated the effects of increasing Pb concentrations on seed germination and early seedling growth of Solanum lycopersicum. Seeds were exposed to 0, 200, 400, and 800 mg L⁻¹ Pb in a randomized block design with split plots and four replications. Evaluations were performed from the 5th to the 14th day after sowing. Normal and abnormal seedlings, primary root length, shoot length, and seedling dry mass were determined. Data were subjected to analysis of variance at 5% probability and polynomial regression when appropriate. Increasing Pb concentrations reduced the percentage of normal seedlings, primary root length, and dry mass. Shoot growth was less sensitive, with the strongest restriction at 800 mg L⁻¹. Pb compromised S. lycopersicum seedling establishment, particularly root development and biomass accumulation, with responses varying according to concentration and evaluation time.