Ecophysiological Effects of Nickel on Boston Fern (Nephrolepis exaltata) under Hydroponic Conditions
Background Objective: Rapid urbanization in recent times has led to increase in heavy metal pollution. Human exposure to various environmental contaminants has increased tremendously over the years. This study investigated the effects of trace concentration of nickel on Nephrolepis exaltata and also determined its suitability as a bio-indicator of Ni in water body. Materials and Methods: Fifteen (15) Nephrolepis exaltata plants were exposed to increasing concentrations of nickel solutions (0.01, 0.1 and 1 ppm) and controls for sixty (60) days. The root, shoot and leaf lengths of the fern at 0, 30 and 60 days were measured. Determination of Leaf chemical contents were carried out as well as Chlorosis and necrosis examination. Results: The findings indicated that Nephrolepis exaltata showed increased root length only after 60 days of administering 0.01 ppm treatment; increased leaf length at day 60 upon treatments with 0.1 ppm and 0.01 ppm of Ni. Nephrolepis exaltata showed significant increase in chlorophyll production at low concentrations (0.1 ppm and 0.01 ppm). Visible signs of toxicity (Chlorosis, frond disconnection and necrosis) were seen in Nephrolepis exaltata only at higher concentration. Conclusion: This study revealed that Nephrolepis exaltata cannot be used as a bio-indicator of Nickel in the environment since it shows toxicity at ≥ 1 ppm. However, the study revealed little sensitivity of the Nephrolepis exaltata (Boston fern) to trace amounts of Ni metal.
Atunwa Bukola Taiwo, Adebayo Alaba Joseph, Oyebanji Adedayo Olamide and Oguntimehin Ilemobayo Ifedayo