Phytoaccumulation of Copper from Irrigation Water and Its Effect on the Internal Structure of Lettuce

There is much concern about the cleanup of toxic contaminants in the environment as human activities increase. The objective of this research was to study the effects of different rates (0, 0.3 and 0.5 g·L −1 ) of (CuCl 2 ) used for irrigation and its translocation in shoots and roots of three varieties: Romaine lettuce (local), Redina lettuce (red) and iceberg lettuce ( Lactuca sativa L.) after 97 days. There was a significant difference in fresh weight and dry weigh for all varieties of lettuce. Differential accumulation and translocation of copper (Cu) in the root and leaf of vegetables were investigated using atomic absorption spectrophotometer. Red plant accumulated higher amounts of Cu (1.89 mg·kg −1 ) in root and (0.71 mg·kg −1 ) in shoot compared to the other three plant species. The accumulation coefficient (AC) and translocation factor (TF) of Cu in three varieties was higher in red followed by local and iceberg. At high concentrations (CuCl 2 : 0.5 g·L −1 ), the light micrographs obtained from the leaf samples of copper-treated plants showed changes and a reduction in the number and the distribution of chloroplasts in palisade and spongy parenchyma cells. All cultivars were able to accumulate significant amounts of Cu, but they have severe symptoms of phytotoxicity when the copper concentration was high.