Effect of Arbuscular Mycorrhizal Fungal Inoculation on Heavy Metal Accumulation of Maize Grown in a Naturally Contaminated Soil

Abstract

A pot culture experiment was carried out to study heavy metal (HM) phytoaccumulation from soil contaminated with Cu, Zn, Pb, and Cd by maize (Zea mays L.) inoculated with arbuscular mycorrhizal (AM) fungi (AMF). Two AM fungal inocula—MI containing only one AM fungal strain (Glomus caledonium 90036) and MII consisting of Gigaspora margarita ZJ37, Gigaspora decipens ZJ38, Scutellospora gilmori ZJ39, Acaulospora spp., and Glomus spp.—were applied to the soil under unsterilized conditions. The control received no mycorrhizal inoculation. The maize plants were harvested after 10 wk of growth. MI-treated plants had higher mycorrhizal colonization than MII-treated plants. Both MI and MII increased P concentrations in roots, but not in shoots. Neither MI nor MII had significant effects on shoot or root dry weight (DW). Compared with the control, shoot Cu, Zn, Pb, and Cd concentrations were decreased by MI but increased by MII. Cu, Zn, Pb, and Cd uptake into shoots and roots all increased in MII-treated plants, while in MI-treated plants Cu, Zn, and Pb uptake into shoots and Cd uptake into roots decreased but Cu, Zn, and Pb uptake into roots and Cd into shoots increased. MII was more effective than MI in promoting HM extraction efficiencies. The results indicate that MII can benefit HMphytoextraction and, therefore, show potential in the phytoremediation of HM-contaminated soils.

KEY WORDS:

• arbuscular mycorrhiza
• heavy metal contamination
• phytoremediation
• Zea mays

ACKNOWLEDGEMENTS

This work is supported by the National High Technology Research and Development Program (863 Program, No. 2001AA640501) of P. R. China, Innovative Research International Partnership Project of Chinese Academy of Sciences (CXTD-Z2005-4), and Talent Foundation of Henan University of Science and Technology (05-008), Henan Province, P.R. China.

Notes

∗C uninoculated, MI inoculated with Glomus caledonium 90036, MII inoculated with a mixture of several AM fungal species.

∗∗Mean values are presented with standard errors of eight replicates in parentheses. Different letters in the same column show a significant difference by Duncan's multiple range test at P < 0.05.

∗C uninoculated, MI inoculated with Glomus caledonium 90036, MII inoculated with a mixture of several AM fungal species.

∗∗Mean values are presented with standard errors of eight replicates in parentheses. Different letters in the same row show a significant difference by Duncan's multiple range test at P < 0.05.