Arbuscular mycorrhiza contribution to the growth performance and heavy metal uptake of Helianthus annuus LINN in pot culture

Abstract

A greenhouse experiment was conducted to assess the arbuscular mycorrhiza contribution to the growth performance and heavy metals (Cd and Pb) uptake of Helianthus annuus L. from polluted soils. Cadmium sulfate (CdSO₄.8H₂O) and lead acetate ((CH₃COO)₂Pb.3H₂O) were applied at the concentrations: Cd- 0,20,40,60,80 mg kg^-1 and Pb-0,250,500,750,1000 mg kg^-1 in 90 plastic pots filled with 5 kg of topsoil each. Propagules of Glomus mosseae (GM) and Glomus intraradices (GI) at 25 g per pot were applied. Non-inoculated pots served as controls. Each treatment was replicated thrice in completely randomized design. Data were analysed using ANOVA and descriptive statistics. Results showed that arbuscular mycorrhiza (AM) fungi significantly (p ≤ 0.05) influenced the number of leaves, plant height and stem girth of sunflower plants only at 80 mg Cd kg^-1 concentration. Highest values of 0.11 mg Cd kg^-1 and 0.29 mg Pb kg^-1 were obtained with GI in the dry shoot of Helianthus annuus while 0.05 mg Cd kg^-1 and 0.23 mg Pb kg^-1 were remediated with GM application. Least values of Cd and Pb were removed when no AM was applied. GM and GI fungi enhanced the growth of Helianthus annuus and the uptake of Cd and Pb; but GI performed better. Also, a significant (p < 0.05) reduction of AM fungi colonization percentage was obtained with increase in Cd and Pb concentrations.

Key words: Glomus mosseae, Glomus intraradices, Helianthus annuus, phytoremediation, polluted soil.