An assessment of the tolerance of Ligustrum ovalifolium Hassk. to traffic-generated Pb using physiological and biochemical markers

This study examined the leaf Pb content, chlorophyll fluorescence parameters (Fo, Fm, Fv, Fv/Fm, Fm/Fo and t1/2), photopigments (Chl a, Chl b, Chl a+b, the Chl a/b ratio, and total carotenoids), as well as total phenolics (free and bound) in privet (Ligustrum ovalifolium Hassk.) in ‘Stara Zvezdara’ Park, located along the avenue with heavy traffic flow (polluted site), and the Arboretum of Belgrade's Faculty of Forestry (control site). Site-dependent variations were observed for all the parameters examined. It was found that Pb accumulated in leaf tissues (3.5–4.2 μg/g) originates from traffic. Results obtained showed that privet is tolerant to the accumulation of Pb generated by traffic, because it maintains optimal photosynthesis and is characterized by active protection mechanisms due to increase in leaf phenolics, which enable it to survive in habitats exposed to chronic Pb pollution stress. Therefore, L. ovalifolium has great potential for urban landscaping.