Abstract: The following three soybean genotypes: Gmx 92-6-10, Gmx 92-5-4E and TGX. 87D1303 were subjected to 0, 50, 00, 50, 00, 50 or 300 Gy of 60Co gamma irradiation at the Ghana Atomic Energy Commission, Kwabenya and sown at the Arable Crops Research Farm of Kwame Nkrumah University of Science and Technology, Kumasi, Ghana to study their dosage response. The 250 Gy dose (LD50 ) reduced both percentage emergence and seedling height by about 50% relative to the 0 Gy dose which served as the control and was therefore used as the dosage appropriate for induced mutations for the genotypes. The bulk of the seeds from the three genotypes were irradiated using the 250 Gy dose and variants from the M2 and M3 generations screened by storing either threshed seeds (Category A) or unthreshed seeds (Category B) at a temperature range of 22-25°C and relative humidity of 30-35% on laboratory wooden shelves for 4 months. Variants which had 80% germination or above after the storage period were selected and considered as putative mutants. Improvement in storability created through mutagenesis was calculated as gain in selection expressed as the difference in the mean percentage germination of the M3 and M2 populations (M3-M2). Genotype Gmx 92-6-10 produced the largest proportion of variants with improved storability particularly at the M2 generation whilst TGX 87D-1303 produced the highest gain in selection at the M3 generation. Variability associated with Category A was higher than that by Category B and this gave room for selecting many variants with improved storability from Category A.