GENETIC DIVERSITY OF FAST-GROWING AND SLOW-GROWING SOYBEAN RHIZOBIA DETERMINED BY RANDOM AMPLIFIED POLYMORPHIC DNA ANALYSIS

The genetic relationships among six strains of rhizobia, including thr ee strains of Rhizobium fredii and three strains of Bradyrhizobium jap onicum, was determined using random amplified polymorphic DNA (RAPD) t echnique. In this study, 46 arbitrary 10mer primers were employed for RAPD, generating a total of 251 informative fragments. A dendrogram of phylogenetic relationships among the six strains was constructed. The results indicated that geographical distribution may affect phylogeny , as there were closer relationships among the four Taiwanese strains. SB138, SB562, SB368 and SB651, than between these strains and USDA192 , which originated from mainland China. The strain USDA110, obtained f rom the United States, was used in the parsimony analysis. The greates t similarity (55.6%), existed between two strains of B., japonicum, SB 562 and SB138, which both, and the lowest R. fredii (44.4%) between tw o strains of R. fredii, SB368 and USDA192. We also found a RAPD marker specific to the four Taiwanese SE strains used in the study. The RAPD technique is a potential tool for the identification of the genetics and systematics of different populations.