RT Journal Article SR Electronic(1) A1 Zheng, Wen Tao A1 Li, Ying A1 Wang, Rui A1 Sui, Xin Hua A1 Zhang, Xiao Xia A1 Zhang, Jun Jie A1 Wang, En Tao A1 Chen, Wen XinYR 2013 T1 Mesorhizobium qingshengii sp. nov., isolated from effective nodules of Astragalus sinicus JF International Journal of Systematic and Evolutionary Microbiology, VO 63 IS Pt_6 SP 2002 OP 2007 DO https://doi.org/10.1099/ijs.0.044362-0 PB Microbiology Society, SN 1466-5034, AB In a study on the diversity of rhizobia isolated from root nodules of Astragalus sinicus, five strains showed identical 16S rRNA gene sequences. They were related most closely to the type strains of Mesorhizobium loti , Mesorhizobium shangrilense , Mesorhizobium ciceri and Mesorhizobium australicum , with sequence similarities of 99.6–99.8 %. A polyphasic approach, including 16S–23S intergenic spacer (IGS) RFLP, comparative sequence analysis of 16S rRNA, atpD, glnII and recA genes, DNA–DNA hybridization and phenotypic tests, clustered the five isolates into a coherent group distinct from all recognized Mesorhizobium species. Except for strain CCBAU 33446, from which no symbiotic gene was detected, the four remaining strains shared identical nifH and nodC gene sequences and nodulated with Astragalus sinicus. In addition, these five strains showed similar but different fingerprints in IGS-RFLP and BOX-repeat-based PCR, indicating that they were not clones of the same strain. They were also distinguished from recognized Mesorhizobium species by several phenotypic features and fatty acid profiles. Based upon all the results, we suggest that the five strains represent a novel species for which the name Mesorhizobium qingshengii sp. nov. is proposed. The type strain is CCBAU 33460T ( = CGMCC 1.12097T = LMG 26793T = HAMBI 3277T). The DNA G+C content of the type strain is 59.52 mol% (T m)., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.044362-0