红壤中丛枝菌根真菌对污泥态铜生物有效性的影响

EFFECT OF ARBUSCULAR MYCORRHIZAL FUNGI ON BIOAVAILABILITY OF COPPER IN SEWAGE-SLUDGE-AMENDED RED SOIL

以玉米为宿主植物 ,研究了不同污泥量 (0、1 %、4% )施入红壤后接种丛枝菌根真菌Acaulosporalaevis、Glomuscaledonium和Glomusmanihotis对菌根侵染率、孢子密度、玉米生长和铜生物有效性的影响。结果表明 ,施用 1 %的污泥可增加接种A laevis的菌根侵染率和孢子密度 ,其玉米地上部和地下部生物量也有显著增加 ,而不接种 (含土著菌根真菌 )、接种G caledonium和G manihotis的菌根侵染率、孢子密度、玉米地上部和地下部生物量却有显著下降 (p<0 0 5 )。施用 1 %的污泥时接种A laevis降低了玉米地上部铜浓度 ,而接种G caledonium和G manihotis却增加了玉米地上部铜浓度 ,另外 ,接种处理增加玉米根部对铜的吸收总量。不同的菌根真菌对重金属的耐受力是不同的 ,只有施入一定的污泥量即在一定污染程度下才能发挥菌根真菌A

The effect of different sewage sludge levels (0%, 1%, 4%) on mycorrhizal infections, spore densities, root and shoot biomass, Cu uptake by maize inoculated with three arbuscular mycorrhizal fungi (A. laevis, G. caledonium and G. manihotis) in the red soil was studied. Mycorrhizal infection, spore densities, root and shoot biomass were increased by 1% sewage sludge in comparison to no sewage sludge when the maize was inoculated with A. laevis, however, mycorrhizal infection, spore densities, and root and shoot biomass were greatly reduced in the three other treatments (p<0.05). When the red soil was amended with 1% sewage sludge the Cu concentrations in the shoot of the maize were NM (noninoculation)>G. manihotis>G. caledonium>A. laevis, and the total Cu content in the root of the maize infected with the three mycorrhizal fungi was higher than that under nonmycorrhizal treatment. The results showed that the tolerance of different arbuscular mycorrhizal fungi to heavy metals varied and A. laevis could remediate heavy metal contaminated soil when the heavy metal concentrations were not very high.