Two strains were isolated from nodules of Phaseolus vulgaris growing in Southeast Spain. The symbiovar phaseoli is present in Agrobacterium leguminum sp. nov., and nodulates Phaseolus vulgaris in Spain

Agrobacterial strains are common endophytes in root nodules from leguminous plants, but its ability to nodulate and establish nitrogen-fixing symbiosis is controversial. Two strains were isolated from nodules of Phaseolus vulgaris growing in Southeast Spain whose 16S rRNA gene sequences showed 99.5% similarity with Agrobacterium radiobacter ATCC 19358T and 99.2% with A. pusense NCIMB 14639T. Multilocus sequence analysis (MLSA) based on partial sequences of recA and atpD genes suggested that these two strains represent a new Agrobacterium species with < 95% similarity with the housekeeping genes of A. radiobacter and A. pusense type strains. PCR amplification of the telA gene, involved in synthesis of protelomerase, confirmed affiliation of strains MOPV5 and MOPV6 to genus Agrobacterium. Both strains nodulated P. vulgaris and the nodC gene analysis showed that they belong to a new and first symbiovar in Agrobacterium genus for which we propose the name phaseoli. DNA-DNA hybridization and phenotypic characterization allowed their differentiation from closely related species. Based on these results we propose the classification of the strain MOPV5 isolated from P. vulgaris into the novel species Agrobacterium leguminum (sv. phaseoli) sp. nov. (type strain MOPV5T