BIOLOGICAL CHARACTERISTICS OF RHIZOBIUM ISOLATED FROM TWO CASSIA SPECIES FROM GUANGDONG
广东两种决明属（Cassia）植物根瘤菌的生物学特性

Nodulation of ten Cassia species from Guangdong province was surveyed. It wasshown that the nodules could appear only in Cassia mimosoides and C. rotundifolia. Tworhizobial strains were isolated each from C. mimosoides and C. rotundifolia and identifiedas slow-growing Rhizobium. Among ten Cassia species tested, the two rhizobial strains fromCassia failed to nodulate the other eight Cassia species, however, they are capable ofnodulating C. mimosoides and C. rotundifolia. Likewise, three rhizobial strains fromMimosaceae and three from Papilionaceae were unable to nodulate other eight Cassia speciesexcept C. mimosoides and C. rotundifolia. Moreover, the two rhizobial strains from Cassiawere able to nodulate four legumes of Mimosaceae and five legumes of Papilionaceae. Thetwo isolates from Cassia were similar to three isolates from Mimosaceae and three fromPapilonaceae in utilization of carbon sources, salt tolerance, PH tolerance and five enzymeactivities.