Slow-growing Bradyrhizobium japonicum strain S32 formed effective nodules on tap and lateral roots of Glycine max cv. 'Kitamusume'. In contrast, strain S32 formed a few large nodules with pink interior and several small nodule-like structures only on the lateral roots of 'Toyosuzu' cultivars. Although acetylene-reduction activity was detected in the nodules of Toyosuzu, the top of the plant showed no response. A color difference between the two cultivars with S32 was observed 25 days after seeding and inoculating.