Heavy Metal Contamination and Risk of Sunflower Germination and Heavy Metal Translocation

Background: Heavy metal contamination in soils adversely affects plant growth, particularly in crops used for phytoremediation, such as sunflower (Helianthus annuus L.). Understanding the response of different sunflower varieties to heavy metal stress is crucial for developing effective phytoremediation strategies.Objective: This study aimed to evaluate the impact of nickel (Ni), cadmium (Cd), and lead (Pb) on the germination, growth attributes, and metal translocation of two sunflower varieties, Hysun-33 and FH-533.Methods: Sunflower seeds of Hysun-33 and FH-533 were sown in sand-filled pots treated with 0, 50, 100, 150, and 200 mM of Ni, Cd, and Pb. Germination rates, shoot and root lengths, and dry biomass were measured after 20 days. Metal concentrations in roots and shoots were analyzed using atomic absorption spectroscopy, and statistical analyses, including ANOVA and regression, were performed to assess the effects of metal concentrations.Results: Germination rates for Hysun-33 decreased from 79% at 0 mM to 0% at 200 mM, while FH-533 dropped from 75% to 5%. Shoot lengths decreased by 47% at 150 mM Ni, and root biomass was reduced by 62% under 200 mM Cd for both varieties.Conclusion: Cadmium posed the greatest threat to sunflower growth, emphasizing the need for enhanced metal tolerance in phytoremediation applications. Reducing heavy metal contamination in crops is vital for improving food safety and public health.