Changes in population occupancy of bradyrhizobia under different temperature regimes.

To elucidate how temperature affects bradyrhizobial ecology, long-term incubations of Bradyrhizobium japonicum USDA 6T, 38, and 123 and of Bradyrhizobium elkanii USDA 76T were conducted under various temperature conditions. Proliferative traits in liquid culture and population occupancies in soil microcosms were compared. The occupancies of USDA 76T and USDA 123 in soil microcosms during long-term incubation changed with the temperature conditions. These results suggest that temperature is an environmental factor affecting the ecology and occupancy of bradyrhizobia in soils.