Bradyrhizobium lablabi sp. nov., isolated from effective nodules of Lablab purpureus and Arachis hypogaea

Abstract

Five strains isolated from root nodules of Lablab purpureus and Arachis hypogaea grown in the Anhui and Sichuan provinces of China were classified as members of the genus Bradyrhizobium. These strains had identical 16S rRNA gene sequences which shared 99.48 %, 99.48 % and 99.22 % similarity with the most closely related strains of Bradyrhizobium jicamae PAC68 T , Bradyrhizobium pachyrhizi PAC48 T and Bradyrhizobium elkanii USDA 76 T , respectively. A study using a polyphasic approach, including 16S rRNA gene RFLP, IGS-RFLP, BOX-PCR, comparative sequence analysis of the 16S-23S rRNA intergenic spacer (IGS) and the recA, atpD and glnII genes, DNA-DNA hybridization and phenotypic tests, showed that the five strains clustered into a coherent group that differentiated them from all recognized species of the genus Bradyrhizobium. Sequencing of nifH and nodC genes and cross-nodulation tests showed that the representative strains CCBAU 23086 T , CCBAU 23160 and CCBAU 61434, isolated from different plants, had identical nifH and nodC gene sequences and were all able to nodulate Lablab purpureus, Arachis hypogaea and Vigna unguiculata. Based upon these results, the name Bradyrhizobium lablabi sp. nov. is proposed for this novel species and strain CCBAU 23086 T (5LMG 25572 T 5HAMBI 3052 T ) is designated as the type strain. The DNA G+C mol% is 60.14 (T m ).

Polyphasic evidence supporting the reclassification of Bradyrhizobium japonicum group Ia strains as Bradyrhizobium diazoefficiens sp. nov.

“…Menna et al, Chang et al, 2011;Zhang et al, 2012), and our results support the use of this methodology for such purposes. Group Ia strains formed distinct and well-supported clades in single-gene phylogenies of atpD, recA and glnII, for which sequences of all described Bradyrhizobium species are available (data not shown).…”

“…Menna et al, 2009; Moulin et al, 2004;Stepkowski et al, 2005;Vinuesa et al, 2008). Recently, sequences of at least three housekeeping genes were used for phylogenetic analysis and taxonomic classification of bradyrhizobia (Chahboune et al, 2011(Chahboune et al, , 2012Chang et al, 2011;Zhang et al, 2012), and our results support the use of this methodology for such purposes. Group Ia strains formed distinct and well-supported clades in single-gene phylogenies of atpD, recA and glnII, for which sequences of all described Bradyrhizobium species are available (data not shown).…”

Nodulation in Dimorphandra wilsonii Rizz. (Caesalpinioideae), a Threatened Species Native to the Brazilian Cerrado

“…The D. wilsonii bradyrhizobial strain DW10.1 (which is in rrs gene group II) belongs to an ITS subgroup supported by a bootstrap of 99% that includes the type strains of B. elkanii USDA 76 T , which was isolated from soybean nodules, B. lablabi which was isolated from Lablab purpureus [37], and B. pachyrhizi PAC48 T and B. jicamae PAC68 T , which were isolated from Pachyrhizus nodules [38]. Strains from the genospecies × and XI of [35] are close to the aforementioned strains, and together with them they form a wide group that also contains strain SEMIA 6099 which was isolated from Dimorphandra jorgei [5] and which has an identity value of 94.4% with respect to DW10.1.…”

Symbiotic efficiency and genetic diversity of soybean bradyrhizobia in Brazilian soils

“…Soybean is the species most commonly used in nodulation tests in studies describing novel Bradyrhizobium species (Jordan, 1982;Kuykendall et al, 1992;Xu et al, 1995;Yao et al, 2002;Rivas et al, 2004;Vinuesa et al, 2005a;Van Berkum et al, 2006;Ramírez-Bahena et al, 2009Chahboune et al, 2011Chahboune et al, , 2012Chang et al, 2011;Wang et al, 2012Wang et al, , 2013Zhang et al, 2012;Guerrouj et al, 2013;Delamuta et al, 2013). The use of soybean in nodulation tests to describe novel species is probably related with its economic importance and the fact that the first described Bradyrhizobium species were isolated from this crop.…”

“…Currently, there are 29 described Bradyrhizobium species: B. japonicum (Jordan, 1982), B. elkanii (Kuykendall et al, 1992), B. liaoningense (Xu et al, 1995), B. yuanmingense (Yao et al, 2002), B. betae (Rivas et al, 2004), B. canariense (Vinuesa et al, 2005a), B. denitrificans (Van Berkum et al, 2006), B. pachyrhizi and B. jicamae (Ramírez-Bahena et al, 2009), B. iriomotense (Islam et al, 2008), B. cytisi (Chahboune et al, 2011), B. lablabi (Chang et al, 2011), B. daqingense , B. huanghuaihaiense , B. oligotrophicum , B. rifense , B. arachidis (Wang et al, 2013), B. retamae (Guerrouj et al, 2013), B. diazoefficiens (Delamuta et al, 2013), B. ganzhouense, (Lu et al, 2014), B. paxllaeri and B.…”