Uptake of atrazine by hyphae of Glomus vesicular-arbuscular mycorrhizae and root systems of corn (Zea mays L.)
1992
Nelson, S.D. | Khan, S.U.
A system, including a specialized treatment vessel for pesticide uptake studies, was developed and experiments were carried out to determine the ability of Glomus intraradices (Schenck & Smith), G. vesiculiferium (Thaxter), and indigenous vesicular-arbuscular mycorrhizae (VAM) fungi to influence 14C-atrazine uptake and transfer to corn. Uptake by root systems with and without VAM infection was compared to uptake by VAM hyphal systems by controlling access to 14C-atrazine-treated soil. Hyphal systems of Glomus species were able to remove 14C-residue from soil and transfer these to corn. Amount of 14C-residue transferred to corn through hyphal systems was highly correlated to the level of VAM root infection which varied among VAM species. In root systems, variations in 14C-residue uptake resulting from mycorrhization were largely explained in terms of the negative correlation between level of infection and root mass located in 14C-atrazine-treated soil. Allocation of 14C-residue to shoot tissues of corn was greater when 14C-residues were taken up through root systems rather than through hyphal systems. There were significant effects of VAM species on 14C-residue compartmentalization between methanol extractable and nonextractable portions of corn tissues. Data from these experiments in a confined soil system were related to VAM cost-benefit relationships and indicate a significant role for VAM in determining atrazine fate in agricultural systems.
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