Synergistic effect of <i>Glomus fasciculatum</i> and <i>Trichoderma pseudokoningii</i> on <i>Heliathus annuus</i> to decontaminate tannery sludge from toxic metals

Abstract

The effect of two soil amendments of tannery sludge (10% and 20%) on growth and metal uptake of Helianthus annuus L. was studied under three treatments of rhizosphere and mycorrhizal fungi. Trichoderma pseudokoningii Rifai was used as rhizosphere fungal inoculum (F) and Glomus fasciculatum (Thax.) Gerd. & Trappe as the mycorrhizal inoculum (M). The third treatment comprised of combined inoculation (F+M). The control (C) treatment was without any inoculum of the fungi. The plants given both the fungus and mycorrhizal (F+M) treatment showed the maximum growth among all treatments. Plants given only fungus (F) and only mycorrhizal (M) treatment also showed significantly better growth as compared with control (C) treatment. Among the two sludge amendments, the statistical analyses of the results showed increase in all growth parameters in lower (10%) sludge amendment ratio. The accumulation of potentially toxic metals (Cd, Cr, Na and Zn) in different parts of H. annuus grown on tannery sludge amended soil increased with increasing concentration of sludge in the soil. The plants treated with both fungus and mycorrhizal (F+M) treatment showed the maximum uptake of metals and thus the synergistic effect of these fungi can be exploited in decontamination of metals from tannery sludge.

Key words: Phytoextraction, tannery sludge, heavy metals, resistant  rhizosphere fungi, Arbuscular mycorrhizal fungi.