[Biodiversity of Rhizobia associated with Acacia melanoxylon grown in South China].

OBJECTIVE

This study aimed to investigate the genetic diversity of 174 isolates of symbiotic bacteria associated with Acacia melanoxylon obtained from 15 sampling sites in Guangdong, Fujian and Jiangxi provinces of China.

METHODS

The 16S rDNA restriction fragment length polymorphism (RFLP) and phylogenetic analyses of the 16S rDNA and housekeeping genes (recA, glnII and atpD).

RESULTS

In the 16S rDNA PCR-RFLP analysis, 9 rDNA types were identified among the 174 isolates; Phylogenetic analyses based on 16S rDNA and housekeeping gene sequences indicated that 34 representative isolates belonged to the genus Bradyrhizobium, Rhizobium, Mesorhizobium in Alpha-Proteobacteria, and the most closely related strains are Bradyrhizobium liaoningense, Bradyrhizobium betae, Bradyrhizobium cytisi, Rhizobium multihospitium and Mesorhizobium plurifarium.

CONCLUSION

All of the isolates could be identified to general, and Bradyrhizobium, Rhizobium or Mesorhizobium could be the dominant microsymbiont. The microsymbionts associated with Acacia melanoxylon showed relative genetic diversity.