Heavy Metal Bioaccumulation in Leek (Allium porrum L.) Cultivars

Abstract

This study investigated the elemental composition and cultivar-dependent variability in the accumulation of heavy metals in leek (Allium porrum L.) grown under field conditions. The aim of the research was to assess how different leek cultivars accumulate essential and potentially toxic elements and to identify genotypic traits influencing heavy-metal uptake under similar environmental conditions. Four cultivars (Albos, De Carentan, Elefant, Lungo Della Riviera) were analyzed for Fe, Mn, Zn, Cu, Co, Ni, Cr, Pb, and Cd contents using atomic absorption spectrometry. Among cultivars, Elefant exhibited the highest Fe, Cu, and Cd contents, while De Carentan accumulated more Zn and Pb. When recalculated to fresh mass, Cd concentrations in leek tissues remained below the permissible limit (0.04 mg.kg⁻¹ fresh matter), whereas Pb levels exceeded the threshold (0.10 mg.kg⁻¹ fresh matter). Principal component analysis (PCA) explained 76.1% of the total variance and revealed distinct clustering of cultivars according to their elemental profiles. Zn, Cu, Pb, and Co were the major contributors to PC1, while Mn and Cr influenced PC2. The findings demonstrate that both soil properties and genetic factors significantly affect heavy-metal uptake and accumulation in leek. Although the analyzed soil was moderately fertile and suitable for vegetable production, elevated Cd and Pb levels underline the need for continuous environmental monitoring, the implementation of soil remediation measures, and careful selection of cultivars with lower accumulation potential to ensure the safety and quality of vegetable produce.