Screening of most potential candidate among different lemongrass varieties for phytoremediation of tannery sludge contaminated sites

Abstract

One of the most sustainable approaches for reclamation of heavy metal contaminated sites is by phytoremediation. Cultivation of aromatic plants in such areas has been proposed by a number of researchers as it fulfills the purpose of phytoremediation alongside monetary benefits. A pot experiment was conducted to screen out most potential candidate among different lemongrass varieties which can be recommended to be grown in tannery effluent contaminated sites. Four consecutive harvests of nine varieties of lemongrass were tested. Translocation factor (TF) < 1 for chromium and cadmium whereas >1 for nickel and lead was observed in all varieties. Bioconcentration factor (BF) > 1 was observed for chromium in Suwarna variety. Photosynthetic pigments, growth parameters, antioxidants, oil content, and yield were highly correlated. Neighbor joining (NJ) cluster analysis was performed to predict the relationship between varieties according to their chromium uptake potential. Endurance of varieties towards metal stress was assessed using chlorophyll a fluorescence kinetics. Maximum reduction potential of chromium (70.07%), lead (85.29%), and cadmium (77.36%) was observed in Suwarna variety. Our study indicated that lemongrass acts as potential phytoextractor for nickel and lead. Suwarna variety appeared to be the best candidate among all the varieties tested owing to its higher biomass and metal uptake potential.