Impact of Mycorrhizae Formation on the Phosphorus and Heavy-Metal Uptake of Alfalfa

Abstract

Three pot experiments were set up to determine how efficiently mycorrhizal fungi affect the uptake, translocation, and distribution of labeled phosphorus (32P), phosphorus (P), and heavy metals in alfalfa (Medicago sativa L.). In experiments 1 and 2, the efficiencies of different arbuscular mycorrhizal fungi (AMF) species including Glomus mosseae, G. etunicatum, G. intraradices and a mixed strain (G. mosseae, Gigaspora hartiga, and G. fasciculatum) on uptake, translocation, and distribution of 32P and P in alfalfa were investigated, respectively. In a third experiment, the efficiency of G. mosseae on uptake and distribution of heavy metals [cadmium (Cd), cobalt (Co), lead (Pb), and combinations] was tested. Results of experiments 1 and 2 suggest that G. mosseae was the most effective at increasing the uptake of 32P and P. Experiment 3 result showed that in the triple-metal-contaminated soil, inoculated plants had greater Co (32.56 mg kg−1) and Pb (289.50 mg kg−1) concentration and G. mosseae enhanced the translocation of heavy metals to shoot. Hence, mycorrhizal alfalfa in symbiosis with G. mosseae can be used for remediation of heavy metals polluted soils with high efficiency.