A novel rhizobial group cluster 9 defined in previous research Tan Z. Y., Wang E. T., Peng G. X. Zhu M.E., Martinez-ROMERO E Chen W. X. (1999) Int J Syst Bacteriol 49 1457-1469 was further characterized by determination of DNA base composition whole-cell protein SDS-PAGE analysis DNA-DNA hybridization 165 rRNA gene sequencing and host specificity These isolates were collected from the wild legumes Amphicarpaea trisperma Coronilla varia and Gueldenstaedtia multiflora growing in arid and semi-arid regions in north-wesern China lsolated within cluster 9 grouped into a single cluster above a similarity level of 90.6% in a cluster analysis based on protein SDS-PAGE and they were differentiated from defined rhizobial species comparative analysis of 165 rRNA gene sequences showed that isolate CCBAU 71623, representing cluster 9 was most related to Rhizobium gallicum and Rhizobium mongolense The DNA-DNA homologies were lower thatn 42.4% among cluster 9 and defined species including R. gallicum and R. MONGOLENSE Theese data indicated that cluster 9 was a unique genomic species lsoateds within this cluster could share their host plants They clould nt nodulate Galega orientalis and Leucarena leucocephala and formed inefeective nodulels on phaseolus vuaris This Group could also be differentiated from defined species by phenotypic characteristics it is therefore proposed as a new species Rhizobium yanglingense with isolate CCBAU 71623 as the type strain.

Eight fast-growing rhizobial isolated from xinjinag soils were identified as Sinorhizobium xinjiangense by analyses of 16S Rrna gene sequences SDS-PAGE of proteins intergenic spacer sequences an DNA-DNA hybridization. Based on all of the results these isolates and the reference strains for S. xinjianggense were a distinct genomic species although the 16S Rrna genes were closely related to that of Sinorhizobium fredii.

A fast-growing rhizobial group isolated from teguminous plants in Hainan Province a tropical region of China is prouposed as a new Rhizobium species on the basis of 16S rRNA gene sequencing DNA-DNA hybridization andphenotypic characterization This new species belongs to the phylogenetic branch which includes Rhizobium leguminosarum We propose the name Rhizoblum hainanense sp. Nov. for this species The strain CCBAU 57015 (166) is the type strain; it has been deposited in the cluture collection of Beijing Agricultural University People's Republic of China

Forty-eight rhizobial isolates from root nodules of Indigofera and Kummerowia, two genera of annual or perennial wild legumes growing in the Loess Plateau in north-western China, were characterized by a polyphasic approach, Two main goups cluster 1 and cluster 2, were defined based upon the results of numerical taxonomy SDS-PAGE of whole-cell proteins and DNA relatedness All the isolates within cluster 1 were isolated from Indigofera and they were identified as Rhizobium strins by 165 Rrna gene analysis DNA relatedness of 29.5-48.9% was obtained among the cluster 1 isotates and the reference strains for defined Rhizobium specties Cluster 2 consisted of isolates from Kummerowia stipulacea and was identified as belonging to Sinorhizobium by 165 Rrna gene analyses DNA relatedness varied from 5.2 to 41.7% among the isolates of cluster 2 and reference strains for Sinorhizbium species considering the existence of distinctive features among these two groups and related species within the genera Rhizobium and Sinohizobium we propose two novel species Rhizobium indigoferae sp. Nov for cluster 1, with isolate CCBAU 71714(=AS 1.3046') as the type strain and Sinorhizobium kummerowiae sp. Nov. for cluster 2, with isolate CCBAU 71042' (=AS 1.3045') as the type strain.

Fifty-five Chinese isolates form nodules of Amorpha fruticosa were characterized and compared with the type strains of teh species and genera of baceria which form nitrogen-fixing symbioses with teguminous host plants A polyphasic approach which inclued RFLP of PCR-amplifiod 165 rRNA genes, multiolcus enzyme elctrophoresis (MLEE) DNA-DNA hybrization 165 rRNA gene sequencing electrophorestic plasmid profiles cross-nodulation and a phenotypic study was used in teh comparatie analysis The isolated originated from several different sites in China and they varaied in their phenotypic and genetic characteristics The majority of teh isolates had moderate to slow growth rates produced acid on YMA and harboured a 930kb symbiotic plasmid (pSym) Five different RFLP patterns were idnetified among the 165 rRNA genes of all lthe isolates isolates grouped by PCR-RFLP of the 165 rRNA genes were also separated into groups by variation in MLEE profiles and by DNA-DNA hybrizdization A representatie isolate from each of these DNA homology groups had a separated position in a phylogenetic tree as determined from sequencing analyss of teh 165 rRNA genes A new species Mesorhizobium amorphae is proposed for th majority of the isolates which belonged to a moderatly slow-to slow-growing acid-producing group based upon their distinct hylogenctic position their unique electrophoretic type, their low DNA homology with reference strains representing the species within the genus Mesorhizobium and their distinct phenotypic features Strain ACCCC 19665 was cholsen as the type strain for M. amorphae sp. nov.