02336naa a2200253 a 450000100080000000500110000800800410001902200140006002400530007410000190012724501870014626000090033352015090034265000140185165300130186565300200187870000170189870000250191570000170194070000170195770000170197470000140199177300770200521359492021-11-09       2021    bl uuuu     u00u1 u    #d  a0723-20207 ahttps://doi.org/10.1016/j.syapm.2021.1262682DOI1 aRHEM, M. F. K.  aThe large mimosoid genus Inga Mill. (tribe Ingeae, Caesalpinioideae) is nodulated by diverse Bradyrhizobium strains in its main centers of diversity in Brazil.h[electronic resource]  c2021  aInga (Caesalpinioideae) is the type genus of the Ingeae tribe in the mimosoid clade. It comprises about 300 species, all trees or treelets, and has an exclusively neotropical distribution, with Brazil as its main center of diversity. In this study, we analyzed the diversity of 40 strains of rhizobia isolated from root nodules collected from ten species of Inga belonging to different types of vegetation in Brazil. Sequences of their housekeeping genes (dnaK, recA, rpoB, gyrB and glnII), 16S rRNA genes, internal transcribed spacer (ITS) regions, as well as their symbiosis-essential genes (nodC and nifH) were used to characterize them genetically. The ability of the rhizobia to form nodules on Inga spp., and on the promiscuous legume siratro (Macroptilium atropurpureum) was also evaluated. A multilocus sequence analysis (MLSA) combined with an analysis of the ITS region showed that the isolates were distributed into four main groups (A-D) within the large genus Bradyrhizobium. Analysis of the nodC and nifH genes showed that the isolates formed a separate branch from all described species of Bradyrhizobium, except for B. ingae. Most of the tested isolates formed nodules on siratro and all isolates tested nodulated Inga spp. Our results suggest a unique co-evolutionary history of Bradyrhizobium and Inga and demonstrate the existence of potential new species of microsymbionts nodulating this important and representative genus of leguminous tree from the Caesalpinioideae mimosoid clade.  aPhylogeny  aRhizobia  aSymbiotic genes1 aSILVA, V. C.1 aSANTOS, J. M. F. dos1 aZILLI, J. E.1 aJAMES, E. K.1 aSIMON, M. F.1 aGROSS, E.  tSystematic and Applied Microbiologygv. 44, n. 6, 126268, November 2021.