Embryogenic callus from unfertilized lime ovules, was subcultured on MT basal medium supplemented with 1000 mg/l malt extract (ME). The calli were exposed to gamma irradiation at 60, 80, 100 and 120 Gy doses. Percentage of cell viability was determined through tetrazolium assay. The highest viability of cells was 73.72% in 60 Gy, and further increase in gamma dose, decreased cell viability. Embryogenesis resulted when calli cultured on MT medium containing 1 mgl-1 GA3. during the study, embryo formation from the calli was difficult, however the calli habituated to growth after 8 months. Calli when subcultured on MT medium without sucrose for 4 weeks as a stress, then subcultured on MT+GA3 medium resulted in stimulated embryogenesis. Mean embryo formation from each 250 mg callus, was approximately 150 after 2 weeks. Addition of high concentrations of GA3 and BA to habituated calli inhibited embryogenesis and then produced callus from pseudobulbils. In irradiated calli, the perentage of embryos from 60 and 100 Gy treatments were 70 and 85 and embryogenesis did not happen at 120 Gy. Activity of peroxidase in irradiated and non-irradiated calli was assessed. Maximum activity of peroxidase was 1.72 in non-irradiated calli. Increase in gamma dose, decreased activity of peroxidase.
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