Study on the Role of Zinc Solubilizing Bacteria in Continuance Cultivation of Wheat and Corn by Using 65Zn

Some microorganisms can increase the solublity of relatively insoluble forms of zinc(Zn) in soils and fulfil the requirements of plants. As evidance for this hypothesis, an experiment was conducted in 2009-10 in a sand culture whitout zinc. In this experiment, factors included two kinds of inoculants with microorganisms and three kinds of zinc sources. Inoculants included pseudomonas fluorescent strain 187 and pseudomonas aeruginosa strain MPFM1; factors of zinc sources included zinc sulfate (ZnSO4), zinc oxid (ZnO) and zinc carbonate (ZnCO3). For detection of Zinc element in plants, (n,γ) reaction was used to convert 64Zn to 65Zn in reactor of Atomic Energy Organization of Iran. Wheat (Triticum aestivum L.) and corn (Zea mays L.) were planted and after growth seasons, 65Zn was computed in all members of plants and all kinds of treatments with the use of High Resolution Germanium Spectrometry (HRGS). The results revealed that: a) in inoculation treatments, the mean of 65Zn activity was more than the treatments whithout inoculation, b) inoculation by zinc solubilizing bacteria (ZnSB) increased the amount of Zn uptake from relatively insoluble Zn and sources, and c) the abilities of these microorganisms to release Zn from relatively insoluble Zn compounds were found to be different.