Iron oxide deposition on axenic and non‐axenic roots of rice seedlings(oryza satival.)1

Wetland plant roots are often coated with iron oxides. The aim of this study was to determine if micro‐organisms growing in the rhizoplane affect the amount of iron oxide deposition. Methods were developed to compare axenic and non‐axenic rice plants grown in environmental chambers and exposed to solutions of ferrous iron. Axenic roots accumulated significantly (p < 0.05) more iron oxides than did non‐axenic roots. The pH of iron solutions after exposure to axenic and non‐axenic seedlings was significantly different. Roots exposed to micro‐organisms from two different soils did not significantly differ in iron oxide deposition or pH of iron solutions. It is therefore hypothesized that although the results show that micro‐organisms have the potential to decrease the amount of iron oxide deposition, this decrease may not result in site‐to‐site differences in iron oxide deposition on wetland plant roots.