Investigation of morphological and enzymatic reactions of some Lemna species against boron (B) and their bioremediation potentials

In this study, growth parameters, antioxidant enzyme activities and bioremediation potentials of Lemna minor L. and Lemna gibba L. (Lemnaceae) exposed to waters with 2, 4, 8, 16, 32, 64 and 128 ppm boron (B) concentrations were investigated under laboratory conditions. To reach this aim, both the plant species were cultured and grown in various B concentrations according to OECD, 2002 test protocol during 7-day test period. Results showed that B accumulation of both plants gradually increased when compared with their B concentration before starting the experiments. Minimum B concentration in dry weight of L. gibba and L. minor were determined in control group as 700.6 and 859.6 mg kg-1 respectively and maximum values were 4007.5 and 5091.7 mg kg-1 in the experiment set with 128 ppm B concentration respectively. However, relative growth rates decreased since the experiment set with 16 ppm B concentration. Results demonstrated that 16 ppm B concentration in water seemed to be a suspectibal endpoint for both plant species that could be used as a critical bioindicator level of B contaminated water. As a result, this study demonstrated an effective and environmentally friendly model for the areas with B pollution to monitor useful B levels in the environment