Survival of Rhizobium trifolii strains on inoculated seed held at 35°C

Abstract

Fifteen Rhizobium trifolii strains, selected from 62 isolations from naturalized white clover (Trifolium repens) plants on the far north coast of New South Wales, were tested for their tolerance to high temperature. They were compared with TAI (the current commercial strain) and CC275e, when used as peat cultures to inoculate seed held at 35°C. TAI showed the most rapid decline and its death rate was significantly higher than that of all except one of the isolates. CC275e showed good survival, and its death rate was similar to the lowest in two out of the three groups in which it was included. Differences between local isolates were small except for two which showed poorer survival.